249,426 results on '"010502 geochemistry & geophysics"'
Search Results
2. Mbi Crater (Cameroon) illustrates the relations between mountain and lowland forests over the past 15,000 years in western equatorial Africa
- Author
-
Kenji Izumi, Gaston Achoundong, Anne-Marie Lézine, Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU), Variabilité à long terme du climat de l'océan (VALCO), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Paris (UP)-Institut de Recherche pour le Développement (IRD)-Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), School of Geographical Sciences [Bristol], University of Bristol [Bristol], Institut de Recherche Agricole pour le Développement [Yaoundé] (IRAD), ANR-06-BDIV-0014,IFORA,Les îles forestières africaines : modèles d'une nouvelle approche de la dynamique de structuration de la biodiversité(2006), ANR-09-PEXT-0001,C3A,Et si la 6ème extinction avait déjà eu lieu ? Causes et Conséquences de la dernière grande ' Crise ' environnementale (3000 ans BP) en Afrique équatoriale atlantique.(2009), ANR-15-MASC-0003,VULPES,VULnerability of Populations under Extreme Scenarios(2015), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)
- Subjects
010506 paleontology ,geography.geographical_feature_category ,Biome ,Biodiversity ,[SDU.STU]Sciences of the Universe [physics]/Earth Sciences ,Climate change ,Ecotone ,Vegetation ,15. Life on land ,010502 geochemistry & geophysics ,01 natural sciences ,Grassland ,Geography ,13. Climate action ,14. Life underwater ,Physical geography ,Younger Dryas ,ComputingMilieux_MISCELLANEOUS ,Sea level ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Pollen-based vegetation, biodiversity, and biome reconstructions over the last 15,500 years from sediment core data at Mbi Crater in the Cameroon highlands (6.089273° N, 10.348549° E; 2015 m above sea level) are used to discuss the behavior of the lower edge of the Afromontane forest facing climate change. The data reveal that the post-glacial forest change gradually happened at Mbi and that the forest-wooded grassland ecotone was highly influenced by the climate variability related to the North Atlantic. The forest disruption and diversity loss intermittently occurred over the whole period, and their vegetation changes temporally match dry-cold events at the northern latitudes during the Younger Dryas, at 9.5–9.1 ka, 8.6–8.0 ka, 6.7–6.0 ka, 3.2 ka, and during the Little Ice Age (LIA). During the LIA, the mountain forest was subject to unprecedented levels of disturbance at all altitudes, unlike the seasonal lowland forests, which appears to have been only marginally affected.
- Published
- 2023
3. After the emergence of the Acheulean at Melka Kunture (Upper Awash, Ethiopia): From Gombore IB (1.6 Ma) to Gombore Iγ (1.4 Ma), Gombore Iδ (1.3 Ma) and Gombore II OAM Test Pit C (1.2 Ma)
- Author
-
Rita Teresa Melis, Flavio Altamura, Margherita Mussi, Laura Pioli, Giancarlo Ruta, Eduardo Méndez-Quintas, Flavia Piarulli, Denis Geraads, Luca Di Bianco, Sabine Gaudzinski-Windheuser, Joaquín Panera, Sol Sánchez-Dehesa Galán, Raymonde Bonnefille, Muséum national d'Histoire naturelle (MNHN), Università degli Studi di Roma 'La Sapienza' = Sapienza University [Rome] (UNIROMA), Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Johannes Gutenberg - Universität Mainz = Johannes Gutenberg University (JGU), Centre de Recherche en Paléontologie - Paris (CR2P), Muséum national d'Histoire naturelle (MNHN)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Università degli Studi di Cagliari = University of Cagliari (UniCa), Centro Nacional de Investigación sobre la Evolución Humana (CENIEH), Università degli Studi di Ferrara = University of Ferrara (UniFE), Universitat Rovira i Virgili, and University of Vigo [ Pontevedra]
- Subjects
010506 paleontology ,biology ,Pleistocene ,Melka Kunture ,Vegetation ,Homo erectus/Ergaster adaptation ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Archaeology ,Geography ,Volcanism ,Human evolution ,[SHS.ENVIR]Humanities and Social Sciences/Environmental studies ,East africa ,Period (geology) ,Assemblage (archaeology) ,Homo erectus ,Lower Pleistocene ,ComputingMilieux_MISCELLANEOUS ,Acheulean ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
International audience; While the emergence of the Acheulean is well documented in East Africa at ~1.7 Ma, subsequent developments are less well understood and to some extent controversial. Here, we provide robust evidence regarding the time period between 1.6 Ma and 1.2 Ma, based on an interdisciplinary approach to the stratigraphic sequences exposed in the Gombore gully of Melka Kunture, in the upper Awash Valley of Ethiopia. Throughout the Pleistocene, the environment differed significantly from elsewhere in Africa because of the elevation at 2000 m asl, the cooler and rainy climate, the Afromontane vegetation, the development of endemic animal species, and the recurrent impact of volcanic activity. At Gombore IB, dated ~1.6 Ma, remains of Homo erectus/ergaster have been discovered, associated with a rich early Acheulean assemblage. The techno-typological analysis of the lithic record from Gombore Iγ (~1.4 Ma) and Gombore Iδ (~1.3 Ma), where substantial areas have been excavated, and the contrasting evidence from Gombore OAM Test Pit C (~1.2 Ma), suggest that the scarcity or lack of large flakes and large cutting tools at the two earlier sites is possibly not just the outcome of sampling bias, but rather of the adaptation of H. erectus/ergaster to the local resources, in a relatively isolated environment. The sites of Gombore gully provide new evidence on the complex pattern of human evolution and adaptation in East Africa during the Lower Pleistocene.
- Published
- 2023
4. Speleothem growth phases in the central Eastern Desert of Egypt reveal enhanced humidity throughout MIS 5
- Author
-
Andrea Schröder-Ritzrau, Norbert Frank, Olaf Bubenzer, Karin Kindermann, René Eichstädter, Daniel Herwartz, Felix Henselowsky, and Ahmed Almoazamy
- Subjects
Mediterranean climate ,010506 paleontology ,geography.geographical_feature_category ,Speleothem ,010502 geochemistry & geophysics ,Monsoon ,01 natural sciences ,Arid ,Geography ,Tropical climate ,Temperate climate ,Stadial ,Precipitation ,Physical geography ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Speleothem deposits in nowadays arid environments are important climate archives, as they indicate phases of enhanced precipitation and can precisely be dated by uranium-series dating. So far only very few of such archives have been found in the today hyper-arid Saharo-Arabian Desert (SAD). Therefore, the study at hand fills a gap that exists for speleothem climate archives in Northeast Africa. A new record from Saqia Cave (Central Eastern Desert, Egypt) documents for the first-time speleothem growth in Egypt for all sub-stages of MIS 5 and singular phases during MIS 6. Most important growth phases occur during periods of strong increase and maximum orbitally-forced northern hemisphere insolation, but also during phases of low insolation, which are in general attributed to aridity in North Africa. Here, at least semi-arid climate conditions are proposed for periods of low insolation during stadials of MIS 5. This suggests an impact of different possible sources of precipitation, apart from large scale shifts of the African monsoon, such as Red Sea Troughs, tropical plums and a larger spatial extent of the Mediterranean winter-rainfall zone. Concerning the spatial rainfall pattern in Egypt, we propose a considerable east to west rainfall gradient in Egypt for the Last Interglacial and suggest a stronger impact of variable moisture sources in the Eastern Desert near the Mediterranean and Red Sea in comparison to the more continental Western Desert of Egypt. This reveals more favorable pre-conditions for an enhanced land use potential in the past. Therefore, the more sustaining wetter climate in the Eastern Desert point to a recurring feasible dispersal corridor for Homo sapiens from the tropical climate into the temperate climate regime throughout MIS 5. Such a more humid climate provided an ideal basis for long-term, favorable environmental conditions east of the Nile Valley, creating a kind of contiguous landscape corridor that may have been attractive to humans and wildlife alike, linking the East African tropical climate regime with that of the temperate zone in Northeast Africa and Eurasia.
- Published
- 2023
5. Archaeobotanical record from dental calculus of a Roman individual affected by bilateral temporo-mandibular joint ankylosis
- Author
-
Flavio De Angelis, Angelo Gismondi, Olga Rickards, Francesco Scuderi, Gabriele Di Marco, Paola Catalano, Alessia D’Agostino, and Antonella Canini
- Subjects
010506 paleontology ,Settore BIO/01 ,Poeae ,Cereals ,010502 geochemistry & geophysics ,01 natural sciences ,Temporo mandibular joint ,Natural (archaeology) ,Dental calculus ,Tribe ,Ankylosis ,medicine ,Calculus ,Bilateral ankylosis of the temporo-mandibular joint ,Light microscopy ,Calculus (medicine) ,0105 earth and related environmental sciences ,Earth-Surface Processes ,biology ,Secondary metabolites ,food and beverages ,Male individual ,biology.organism_classification ,medicine.disease ,Urticaceae ,Geography ,Pollen - Abstract
Ancient dental calculus represents one of the most recent and innovative sources of archaeobotanical record. Exploring this matrix, diet, past ecology, and ethnobotanical practices of antique communities may be elucidated. In the present case-study, the tartar of an Imperial Roman man, likely a salt worker, found in the necropolis of Castel Malnome (Rome, Latium, Italy) and affected by bilateral temporo-mandibular joint ankylosis, was investigated. Despite his rare and extremely disabling affection, this male individual reached adulthood thanks to the forced removal of the anterior teeth, which allowed him to eat. Starches of Poeae and Triticeae tribe were detected, although the largest amount of the granules appeared gelatinized, suggesting that maybe the inhumate consumed well-cooked and semi-liquid stuff, due to his non-functional masticatory activity. Urticaceae and clover pollen grains documented unintentional aspiration or voluntary use of these plants as ingredients for meals and therapeutic decoctions. Indeed, since Roman times, written sources have documented nettle as an anti-inflammatory remedy to treat joint and muscle pains. Finally, the identification of secondary metabolites ascribable to the Brassicaceae family, Artemisia L., and Ephedra L. genera, paves the way for hypothesizing the consumption of these Mediterranean species with several nutritional and nutraceutical properties. All this evidence opens a picture window onto the life of this man, which should be well integrated into his community and natural environment despite the functional impairment.
- Published
- 2023
6. Do I have something in my teeth? The trouble with genetic analyses of diet from archaeological dental calculus
- Author
-
Courtney A. Hofman, Zandra Fagernäs, Allison E. Mann, Rita M. Austin, James A. Fellows Yates, and Elizabeth A. Nelson
- Subjects
010506 paleontology ,Biology ,010502 geochemistry & geophysics ,medicine.disease ,01 natural sciences ,Archaeology ,stomatognathic diseases ,Ancient DNA ,Metagenomics ,medicine ,Calculus ,Identification (biology) ,Microbiome ,Calculus (medicine) ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Dental calculus and other preserved microbiome substrates are an attractive target for dietary reconstruction in past populations through a variety of physical, chemical, and molecular means. Recently, studies have attempted to reconstruct diet from archaeological dental calculus using archaeogenetic techniques. While dental calculus may provide a relatively stable environment for DNA preservation, the detection of plants and animals possibly consumed by an individual through DNA analysis is primarily hindered by microbial richness and incomplete reference databases. Moreover, high genomic similarity within eukaryotic groups 1. Introduction 2. Materials and methods 3. Results 3.1. Effects of low read counts on damage patterns 3.2. Identification of dietary reads from synthetic datasets 3.3. Identification of dietary reads from real datasets 4. Discussion and conclusions 4.1. Checklist for authors and reviewers 4.1.1. Field/storage contamination 4.1.2. Is the laboratory methodology suitable for aDNA authentication? 4.1.3. Is the database and pipeline suitable? 4.1.4. Is the taxonomic resolution analyzed sufficient for reliable interpretation? 4.1.5. Have unexpected taxa been reported and evaluated? 4.1.6. Have laboratory controls been evaluated alongside samples? 4.1.7. Has evidence of aDNA authenticity been provided? 4.1.8. Is there other evidence supporting that dietary organisms were consumed?
- Published
- 2023
7. Changes in patterns of mineral and chemical elements in bottom sediments of Lake Baikal (Russia) as high-resolution records of moisture for the past 31–16 ka BP
- Author
-
Ekaterina V. Parkhomchuk, A. P. Fedotov, O. G. Stepanova, T.O. Zheleznyakova, V. A. Trunova, S. M. Krapivina, A.A. Legkodymov, and S. S. Vorobyeva
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Pleistocene ,Estuary ,Glacier ,010502 geochemistry & geophysics ,01 natural sciences ,Clastic rock ,Tributary ,Physical geography ,Meltwater ,Bay ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The high-resolution biochemical records (SRXRF, ICP-MS and FTIR analyses) of bottom sediments were used for the reconstruction of clastic flux into Lake Baikal via the Barguzin River as moisture and glacier indexes from 1631 ka BP. According to the obtained data, proxies of a high supply of clastic flux by the river are high: the content of feldspar and LREE/HREE, Rb/Sr and Th/Mo ratios. We sampled a sediment core extremely close to the estuary of the Barguzin River. It seems that the water budget of the Baikal tributaries dramatically reduced ca. 34–30 ka BP, and the lake water level was minimum (less than 35–40 m compared to the present) for the last 34 ka. The lake water level has gradually increased from ca. 30 to 25–23 ka BP, and it was likely linked with the activity of the East Asia Monsoon. The very contrasting changes in chemical and mineralogical records were ca. 29.5 ka BP, and these changes were very likely associated with the Heinrich-3; however, there were no significant changes in the records around the Heinrich-2. Our records revealed some intensification of the clastic flux of the Barguzin River into the Barguzin Bay ca. 25–23 ka BP. The Baikal event ca. 21.5–22.5 ka BP was characterized by a sharp reduction of the influx of clastic material into the Barguzin Bay. The time span of 19.5–18 ka BP was the last time that the Barguzin River inflow increased during the Late Pleistocene. This increase in the water budget was at arid regional conditions, and we assumed it could occur due to the contribution of meltwater from glaciers of the Barguzin Ridge. It is most likely that at the regional Late Pleistocene/Holocene transition (around 12–13 ka BP), a rapid rise of the water budget of the Barguzin River occurred, while the lake level was not high, and the sediments deposited from 12(13)–16.5 ka BP could be directly eroded by a kill of the Barguzin River. In general, the obtained records show that an increase in the water budget of the Barguzin River was gradual. The duration of high inflow into the Barguzin Bay was ca. 1.5 ka, while the reductions of this inflow were dramatic.
- Published
- 2023
8. The middle to Late Holocene environment on the Iturup Island (Kurils, North Western Pacific)
- Author
-
Boris K. Biskaborn, Philipp Hoelzmann, Nadezhda G. Razjigaeva, Tatiana R. Makarova, Bernhard Diekmann, L. V. Golovatyuk, Larisa Nazarova, Marina S. Lyashevskaya, and Larisa A. Ganzey
- Subjects
010506 paleontology ,biology ,Sediment ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Diatom ,13. Climate action ,Stage (stratigraphy) ,Period (geology) ,14. Life underwater ,Physical geography ,Bay ,Geology ,Holocene ,Sea level ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Marine transgression - Abstract
The Kuril Islands stretch southwest from Kamchatka, Russia, to Hokkaido, Japan and separate the Sea of Okhotsk from the northern Pacific Ocean. A series of transgressions and regressions linked to variations in climatically affected global ice volume are among the most important drivers of Holocene environmental changes in the region. Despite a long research history, reconstructions of the Holocene palaeoenvironment are sparse with inconsistent interpretations, arising from insufficient dating control, different temporal resolutions, and specific local geographical features, such as high tectonic activity and the isolated nature of the area. We have investigated a 550 cm lake sediment section from Iturup Island, the largest among the Kuril Islands. The 6600 year old sediment section was studied using sedimentological, geochemical, chironomid, diatom, and pollen analyses to reconstruct environmental and climatic changes and sea level fluctuations (transgression – regression stages). During the warm late phase of the Middle Holocene (6600–4400 cal BP) an open bay or lagoon with shallow overgrown littorals existed at the sampling site. The cooling between 5600 and 4400 cal BP can be correlated with Neoglacial cooling. The cool period between 4200 and 3200 cal BP was a transition towards the formation of a freshwater lagoon and can be related to a decline of the Japan Late Jomon transgression (Sakaguchi, 1983). Between 3200 and 2800 cal BP the lagoon separated from the marine environment in response to a further sea level decrease during the Japan Latest Jomon cold stage and regression. The following increase in the share of broad-leaved pollen indicated a slight warming (Yayoi transition stage) that was interrupted by a short-term cooling spell between 1500 and 1400 cal BP (cold Japan Kofun stage). The period between ca 1100 and 800 cal BP can be related to the European Medieval Climate Anomaly (MCA) or relatively dry Japan Nara-Heian-Kamakura warm stage. The Little Ice Age cooling and Edo regression were evident after ca 800 cal BP. Modern warming however is not well seen in the investigated core.
- Published
- 2023
9. Review of speleothem records of the late Holocene: Indian summer monsoon variability & interplay between the solar and oceanic forcing
- Author
-
Raghavan Krishnan, Phanindra Reddy A, and Naveen Gandhi
- Subjects
Wet season ,010506 paleontology ,geography ,geography.geographical_feature_category ,Intertropical Convergence Zone ,Northern Hemisphere ,Speleothem ,010502 geochemistry & geophysics ,Monsoon ,01 natural sciences ,Sea surface temperature ,Climatology ,Roman Warm Period ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Indian summer monsoon (ISM) variability in the late Holocene (last 4000 years) is of great interest as the arid phase of ISM and cultivation of kharif (rainy season) crops started in this period. The present study aims to revisit the available speleothem records to study ISM rainfall variations and possible controlling factors in different Indian regions viz., core monsoon zone (CMZ), peninsular, the Himalaya, and the Bay of Bengal in the last 4000 years. The late Holocene encompasses notable global warm periods viz., Medieval Climate Anomaly, Roman Warm Period (RWP) & Minoan Warm Period, and cold periods viz., Dark Age cold period and Little Ice Age (LIA). ISM rainfall declines until the middle of RWP in all the regions. The decline is linked with the southward migration of the Intertropical convergence zone caused by the northern Hemisphere summer insolation. Though the Solar insolation follows the same trend, all the records show large variability with the disappearance of the declining trend around the middle of RWP. This change coincided with the reversal in the north Atlantic Sea surface temperature (SST) trend, northern hemisphere temperature, and abrupt changes in the southeastern Indian Ocean SST. This period also witnessed high El-Nino Southern Oscillation activities. This synergy of ISM variations in the characterized zones falls apart during the pre-LIA with a slight increasing (decreasing) trend in CMZ and Bay of Bengal (peninsular and Himalayan). The spatially variable response of ISM rainfall in recent centuries might be caused by the interaction between internal variability and external forcing and also by anthropogenic-induced warming and aerosol forcing.
- Published
- 2022
10. Paleo-glacial and paleo-equilibrium line altitude reconstruction from the Late Quaternary glacier features in the Pir Panjal Range, NW Himalayas
- Author
-
Reyaz Ahmad Dar, Omar Jaan Paul, and Shakil Ahmad Romshoo
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Cirque ,Last Glacial Maximum ,Glacier ,010502 geochemistry & geophysics ,01 natural sciences ,Altitude ,Loess ,Deglaciation ,Glacial period ,Physical geography ,Quaternary ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Paleoclimatic constraints from mountain ranges separating major climate systems are important in understanding past climatic changes. Using the present-day glacial geomorphology combined with the GlaRe model, the last glacial maximum (LGM) of seven representative valley glaciers of the Pir Panjal Range (PPR), Kashmir Himalaya was reconstructed. The Range lies at the interface of the tropical and temperate climates in the NW Himalayas. The glacier reconstructions showed that the glaciers in the Range advanced ~10 km down the present-day cirque margins and attained a thickness of more than 200 m during the LGM. Using six different methods, the equilibrium line altitude (ELA) changes in the selected valleys of the PPR were estimated for which the LGM was reconstructed. ELA depressions calculated for the LGM vary from 374 m to 416 m with a mean of 395 m. The weighted average ELA of the Range lies at an altitude of 3922 m a.s.l showing a general increasing trend from SE to NW of the Range. The published chronology of the loess deposits, a proxy for glacial aridity, shows the evidence of significant glacial advances starting around 350 kya in the valley, which is consistent with the evidence of both the pre- and post-LGM advances observed in this study. The presence of extensive glacier features all across the PPR and the presence of a few small heavily debris-covered glaciers in the Range points towards the rapid deglaciation in the area.
- Published
- 2022
11. The equatorial Indian Ocean upper water-column structure influenced by cross-basinal water exchange over the last ~40000 years
- Author
-
Ramanand Yadav, Jayu Narvekar, and Sushant S. Naik
- Subjects
Marine isotope stage ,010506 paleontology ,biology ,Mixed layer ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Foraminifera ,Water column ,Oceanography ,Deglaciation ,Photic zone ,Thermocline ,Holocene ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The central equatorial Indian Ocean (CEIO) is influenced by both, summer and winter monsoon and is known for cross basin exchange of water between the Arabian Sea (AS) and the Bay of Bengal (BoB). Here, we present planktic foraminiferal assemblage record from a sediment core (SSD-044/GC-01, 5°N; 77°E) from the CEIO, which is in the pathway of this cross-basin water exchange, in order to reconstruct changes in upper water column structure during the last 43 ka, at millennial year timescales. Our data displays an increase in ratio of mixed layer eutrophic to mixed layer oligotrophic foraminifer species from MIS (Marine Isotope Stage) 3 to MIS 2 which further decreased sharply during the last deglaciation and remained low thereafter. This trend matches well with the sedimentary Corg content which is interpreted as a productivity signal, in line with other studies from this region. Furthermore, the relative abundance of thermocline foraminifer species displayed highest values during MIS 3, a decrease through the MIS 2, a sharp decrease through the early deglaciation and an increase thereafter into the Holocene. Our records suggest that the increased productivity at this site seems to be fed by nutrient injection from nutricline to the photic zone which manifests in a corresponding increase in thermocline foraminifera species. The nutrient injection to the photic zone maybe a result of increased vertical/convective mixing due to increased flow of cooler/high-salinity BoB water probably caused by decreased freshening of the BoB during glacials. Furthermore, our data suggests a warm, stratified upper water column and low surface nutrient (oligotrophic) conditions during the last deglaciation and the Holocene.
- Published
- 2022
12. Reconstruction of the Persian Gulf SST variability over the last five millennia
- Author
-
Ezatollah Safarkhani, Dariush Yarahmadi, Siyamack Sharafi, and Mohammad Ali Hamzeh
- Subjects
010506 paleontology ,biology ,Terrigenous sediment ,Northern Hemisphere ,Tropics ,Globigerina bulloides ,010502 geochemistry & geophysics ,biology.organism_classification ,Convergence zone ,01 natural sciences ,Foraminifera ,Sea surface temperature ,Oceanography ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Sea surface temperature (SST) variation in the Persian Gulf (PG) is investigated based on Mg/Ca ratio measured in the planktonic foraminifera Globigerina bulloides tests from a sediment core spanning the past 5000 years recovered from west of the Strait of Hormoz. The Mg/Ca SST data indicate a 3 °C fluctuation range with an overall temperature increase trend since the mid-Holocene. The average SST of the PG in the intervals of 5–4.2, 4.2–3, 3–1.8, 1.8–1 and 1 cal kyr BP to present, was 26.1, 26.8, 25.8, 26.3 and 26.7 °C, respectively. SST increase trend in the PG is attributed to seasonally opposing insolation changes led to northern hemisphere extra-tropics cooling and tropics warming. The short spells of decreased (increased) SST indicate a high correlation with an increase (decrease) in terrigenous silt deposited in the PG, representing humid (dry) climate conditions in the Middle East. Likely, northward migration of the Inter-tropical convergence zone during the warmer episodes of the mid to late Holocene results in a change to a drier climatic regime in S Iran. Although Arabian Sea SST has a considerable role in SST variations in the PG, however, SST of this landlocked water body is mainly controlled by a continental climate.
- Published
- 2022
13. Sediment dynamics and post-glacial evolution of the continental shelf around the Blanes submarine canyon head (NW Mediterranean)
- Author
-
Ruth Durán, José Luis Sanz, Rut Pedrosa-Pàmies, Galderic Lastras, David Amblas, Aaron Micallef, and Miquel Canals
- Subjects
Canyon ,geography ,geography.geographical_feature_category ,010504 meteorology & atmospheric sciences ,Terrigenous sediment ,Continental shelf ,Sediment ,Geology ,Continental shelf pump ,Submarine canyon ,Sede Central IEO ,Aquatic Science ,010502 geochemistry & geophysics ,01 natural sciences ,Sedimentary depositional environment ,Oceanography ,Continental margin ,13. Climate action ,14. Life underwater ,Medio Marino ,0105 earth and related environmental sciences - Abstract
The Blanes submarine canyon (BC) deeply incises the Catalan continental shelf in the NW Mediterranean Sea. As a consequence of the closeness (only 4 km) of its head to the coastline and the mouth of the Tordera River, the canyon has a direct influence on the shelf dispersal system as it collects large amounts of sediment, mainly during high-energy events. Multibeam bathymetry, backscatter imagery and very-high resolution seismic reflection profiles have allowed characterizing the morphology of the continental shelf around the canyon head, also identifying sediment sources and transport pathways into the canyon. The morphological data have also been used to reconstruct the evolution of the continental shelf during the last sea-level transgression so that the current understanding of shelf-to-canyon sediment exchanges through time could be improved. The continental shelf surrounding the BC consists of both depositional and erosional or non-depositional areas. Depositional areas display prominent sediment bodies, a generally smooth bathymetry and variable backscatter. These include: (i) an area of modern coarse-grained sediment accumulation that comprises the inner shelf; (ii) a modern fine-grained sedimentation area on the middle shelf offshore Tossa de Mar; and (iii) a modern sediment depleted area that covers most of the middle and outer shelf to the west of the canyon head. Erosional and non-depositional areas display a rough topography and high backscatter, and occur primarily to the east of the canyon head, where the arrival of river-fed inputs is very small. In agreement with this pattern, the continental shelf north and west of the canyon head likely is the main source of shelf sediment into the canyon. To the north, a pattern of very high backscatter extends from the coastline to the canyon head, suggesting the remobilization and off-shelf export of fines. Additionally, relict near-shore sand bodies developed over the Barcelona shelf that extend to the canyon head rim constitute a source of coarse sediment. High-energy processes, namely river floods and coastal storms, are the main controls over the river-shelf-canyon sediment exchange. River floods increase the delivery of terrigenous particles to the coastal system. Storms, mainly from the east, remobilize the sediment temporarily accumulated on the shelf towards the canyon head, so that the finer fractions are preferentially removed and a coarse lag is normally left on the shelf floor. Exceptionally, very strong storms also remove the coarse fractions from the shelf drive them into the canyon. Processes like dense shelf water cascading, which is much more intense in canyons to the north of BC, and the Northern Current also contribute to the transport of suspended sediment from far distant northern sources. During the last post-glacial transgression the BC had a strong influence on the evolution of the inner continental margin, as it interrupted the shelf sediment dispersal system by isolating the shelves to its north and south, named La Planassa and Barcelona shelves, respectively.
- Published
- 2023
14. Landscape evolution around the oppidum of Bibracte (Northern Massif Central, France) from the Late Iron Age to the Post-Mediaeval period
- Author
-
Petra Goláňová, Libor Petr, Romana Kočárová, Vincent Guichard, Isabelle Jouffroy-Bapicot, Petr Kočár, Katarína Adameková, Jan Petřík, Laboratoire Chrono-environnement - CNRS - UBFC (UMR 6249) (LCE), Centre National de la Recherche Scientifique (CNRS)-Université de Franche-Comté (UFC), Université Bourgogne Franche-Comté [COMUE] (UBFC)-Université Bourgogne Franche-Comté [COMUE] (UBFC), and BIBRACTE EPCC
- Subjects
010506 paleontology ,geography.geographical_feature_category ,[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory ,Cultural landscape ,Pastoralism ,Forest management ,Drainage basin ,Massif ,15. Life on land ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,Mosaic ,Geography ,Period (geology) ,Sedimentary rock ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The considerable intensification of human activity in the second and first centuries BC in Central Europe was related to the sudden appearance of a network of large fortified towns, which are known as oppida. Bibracte was one of the most important oppida in France, but knowledge about the evolution of its hinterland is still incomplete. This article addresses the evolution of the landscape surrounding this oppidum. Our research was based on a study of sedimentary profiles sampled around the archaeological site and examined by physical, geochemical and palaeoecological analyses. Sediment sequences indicate that the earliest human-induced erosion associated with geomorphological change occurred in the 4th–1st century BC. Geochemical results indicate ancient mining and metallurgy in the catchment during the same time. Palaeoecological proxies from the same period point to a mosaic of an open cultural landscape with locally suppressed forest vegetation and prevailing pastoralism. Anthropogenic impact resurged in the 11th–13th centuries AD and was associated with livestock grazing and rye (Secale cereale) cultivation. Thereafter, the reconstructed human impact from the 15th century AD onwards was probably related to forest management focused on timber floating as well as to the cultivation of chestnut (Castanea sativa) and hemp (Cannabis sativa).
- Published
- 2022
15. Environmental changes during the Late-Glacial and Early Holocene at the Gourd des Aillères mire in the Monts du Forez Mountains (Massif Central, France)
- Author
-
André-Marie Dendievel, Yun Deng-Amiot, Karen K. Serieyssol, Jean Nicolas Haas, Franck Fassion, Célia Beaudouin, Irka Hajdas, Jacqueline Argant, Christine Oberlin, and Hervé Cubizolle
- Subjects
010506 paleontology ,Oldest Dryas ,Macrofossil ,Older Dryas ,010502 geochemistry & geophysics ,01 natural sciences ,Allerød oscillation ,Preboreal ,Physical geography ,Glacial period ,Younger Dryas ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
In the granitic part of the eastern Massif Central (France), the Gourd des Ailleres (GDA) mire provides one of the only Late-Glacial and Early Holocene sequences with a continuous sedimentation since the Oldest Dryas around 16000 years calibrated Before Present (16 ka cal. BP). Bioclimatic and hydrological changes were reconstructed based on sedimentological parameters, as well as by means of plant and animal macrofossils, pollen, and diatoms analyses through time. The environmental history of this site started with a small lake formed behind a moraine-dam. The multi-proxy study of the sedimentary sequence demonstrated that the coldest conditions took place around 14.3 ka cal. BP, at the very end of the Oldest Dryas. The Bolling period (14.2–13.9 ka cal. BP) was obviously warmer than the Allerod period (13.9–12.8 ka cal. BP) in the Monts du Forez Mountains. However, both chronozones presented a short cooling phase: the Intra Bolling Cold Period (IBCP) and the Intra Allerod Cold Period (IACP), respectively. The Older Dryas (14–13.9 ka cal. BP) was identified for the first time in this region based on pollen and diatom indicators. Thereafter, the Younger Dryas (12.9–11.7 ka cal. BP) was characterised by major temperature fluctuations. Windy conditions prevailed as indirectly demonstrated by the high frequency of Aulacoseira diatoms in the sequence. The onset of the Holocene was dated to 11.7 ka cal. BP. Peat-forming processes started thereafter due to the quick postglacial warming and the former GDA lake finally evolved into a limnogenous mire at the end of the Preboreal (10.4 ka cal. BP).
- Published
- 2022
16. Upper Palaeolithic sites and where to find them: A predictive modelling approach to assess site expectancy in the Southern Levant
- Author
-
Hannah Parow-Souchon, Mirijam Zickel, and Heiko Manner
- Subjects
010506 paleontology ,geography.geographical_feature_category ,Elevation ,Terrain ,Vegetation ,010502 geochemistry & geophysics ,Spatial distribution ,01 natural sciences ,Natural (archaeology) ,Geography ,Spatial analysis ,Cartography ,Predictive modelling ,Wadi ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Site preservation and associated terrain characteristics are among the major agents controlling the spatial distribution and discoverability of late Quaternary archaeological sites. However, site expectancy in extensive areas can be determined using a combination of geoarchaeological investigation and digital spatial analysis. In that sense a prediction model, respectively the result of a Multi Criteria Decision Analysis (MCDA), is presented to highlight areas with a high potential to contain Upper Palaeolithic sites in the Eastern Mediterranean and bordering arid margins. Based on detailed on-site analysis in the Wadi Sabra region, with its many sites and the location of other well-known sites in the southern Levant, eight individual parameters, aspect (cardinal point), elevation, geomorphology, hydrogeology, drainage network, slope inclination, vegetation, and a terrain ruggedness index (TRI) are evaluated and tested for significance. The statistical results confirm a significant divergence of the spatial distribution of Upper Palaeolithic sites from the distribution of natural terrain position factors. This allows for a definition of parameter classes with a high site expectancy and their use in a predictive model. For the results map, the site expectancy factors determined in this way were intersected with each other, thus enabling a distinction between areas with a high and low site occurrence probability. The accuracy of the presented result is assessed by the implementation of another MCDA pass based on an independent dataset of archaeological survey sites and compared to the original. Both datasets complement each other and can show the potential for further investigations with more numerous site datasets as well as more detailed spatial information. A local classification based on high-resolution elevation information and field data is evaluated for the Wadi Sabra, Southern Jordan, which can confirm yet further specify the result from the MCDA.
- Published
- 2022
17. Evaluating Holocene natural hazards in the French Massif Central from a regional lake sediment approach
- Author
-
Victor Arricau, Anthony Foucher, Sébastien Salvador-Blanes, Marlène Lavrieux, Léo Chassiot, Wender Fleurdeus, Emmanuel Chapron, Laurent Perdereaux, Mikael Motelica-Heino, and Isabelle Gay-Ovejero
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Geochemistry ,Outburst flood ,Massif ,Mass wasting ,Fault (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Maar ,law.invention ,law ,Glacial period ,Radiocarbon dating ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Geophysical surveys in the Lakes Tazenat, Aydat, Chambon and Lacassou combined with a multiproxy study of sediment cores highlight Late Holocene abrupt environmental changes in the northern part of the French Massif Central (FMC). Dating landslide-induced dust layers and subaqueous slope failures impacting lake basin sedimentary fills suggest regional triggering by palaeo-earthquakes (cluster of events) either in the Puy-de-Sancy volcano area, or along the regional Limagne fault. In the present study, a cluster of palaeo-earthquakes occurring in the Sancy area between AD 1243 and 1270 are documented in the Lakes Montcineyre, Chauvet, Pavin and Guery, as well as by the formation of Lake Lacassou following the last emplacement of the Dent du Marais landslide in the Chaudefour glacial valley around AD 1250 ± 30. Former cluster of earthquakes occurring near the Limagne fault between AD 580 and 650 are evidenced in Lake Tazenat and in maar Lake Pavin. Lake Pavin present lake-level was similarly favoured by the cluster of earthquakes between AD 1243 and 1270 and the occurrence of a slump and an outburst flood event resulting in the bypassing of a palaeo-outlet. Holocene earthquakes near the Limagne fault are suggested in maar Lake Tazenat by coeval mass wasting deposits (MWDs) around 2250 ± 50 cal. BP and around 2730 ± 30 cal. BP. A landslide-induced dust layer dated between 2760 and 2520 cal. BP at the transition from paludal to lacustrine deposits in the Chaudefour glacial valley is suggesting that the formation of Lake Chambon resulted from a first emplacement of the Dent du Marais landslide. Radionuclides and radiocarbon dating in Lake Tazenat suggest variable sedimentation rates over the last millennia due to: (i) floods during the Little Ice Age, (ii) coeval MWDs at the basin edges and an erosive turbidite in the central basin between AD 575 and 625, and (iii) lake eutrophication since AD 1945. More gravity cores are needed to directly sample and date the youngest generation of coeval MWDs detected on seismic profiles in order to test the impact in this lake of the cluster of major historical earthquakes in the FMC between AD 1450 and 1490 near the Limagne fault.
- Published
- 2022
18. Static and seismic bearing capacity of shallow strip foundations on slopes
- Author
-
Giovanni Biondi, Orazio Casablanca, Ernesto Cascone, and Giuseppe Di Filippo
- Subjects
Method of characteristics ,0211 other engineering and technologies ,Earth and Planetary Sciences (miscellaneous) ,Geotechnical engineering ,02 engineering and technology ,Bearing capacity ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,Bearing capacity earthquakes finite-element modelling footing/foundation slopes stress analysis ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
In this paper the static and seismic values of bearing capacity factors for shallow strip foundations adjacent to slopes have been evaluated using the method of characteristics, accounting, through the pseudo-static approach, for the effect of horizontal and vertical inertia forces arising in the soil and transmitted by the superstructure. Differently from most of the available studies, the effect of the inertia forces in the soil, due to the seismic wave propagation, and the effect of inertia forces acting in the superstructure, due to the structural seismic response, are dealt with independently. It was also demonstrated that the above-mentioned effects can be superimposed without significant error. Original empirical formulas and, in some cases, closed-form solutions, have been provided to calculate bearing capacity factors or suitable corrective coefficients which allow accounting for slope inclination and for horizontal and vertical seismic accelerations in the soil and in the superstructure. The proposed solutions, obtained assuming Hill's and Prandtl's failure mechanisms, have been checked against those obtained through finite-element analyses and compared with results already available in the literature.
- Published
- 2022
19. Toxicological effects of nanoplastics and phenanthrene to zebrafish (Danio rerio)
- Author
-
Kaihang Xu, Liyan Tian, Didi Liu, Zhuozhan Zhuang, Wenjie Ai, Jun Wang, and Qiuping Wang
- Subjects
Pollutant ,animal structures ,Single exposure ,Spinal curvature ,010504 meteorology & atmospheric sciences ,biology ,fungi ,Danio ,Geology ,Phenanthrene ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Andrology ,chemistry.chemical_compound ,Human fertilization ,chemistry ,embryonic structures ,Toxicity ,Zebrafish ,0105 earth and related environmental sciences - Abstract
Despite the known hazards to wildlife, plastic waste to waterways and oceans continues to increase at alarming rates every year. Nanoplastics are a breakdown product of plastic debris in the environment (0.1–100 nm). Their small size renders them bioavailable, and they are likely to accumulate/adsorb persistent organic pollutants, which could increase their toxicity. In this study, we evaluated the effects of nanoplastics and phenanthrene on the early life stages of zebrafish. Zebrafish embryos were exposed to fluorescent nanoparticles and observed with fluorescence microscopy. Polystyrene nanoplastics (80 nm) attached to the embryonic chorionic membrane and were ingested when zebrafish reached 144 h after fertilization, the point at which they first open their mouth, as observed by the fluorescence in their intestines. Exposure alone or in combination with phenanthrene resulted in zebrafish pericardial edema, spinal curvature, increased embryonic heart rate, shortened body length, and increased mortality. Co-exposure to 5 mg/L nanoplastics and 0.1 mg/L phenanthrene caused more negative effects on length, teratogenicity and mortality of zebrafish embryos than the corresponding concentrations of single exposure. This study provides clear evidence that nanoplastics can be ingested by zebrafish larvae, thus future work to assess the toxicological effects is important to marine wildlife management.
- Published
- 2022
20. Visualization and digitization of model tunnel deformation via transparent soil testing technique
- Author
-
Zhikai Zeng, Wengang Zhang, Daifeng Wu, Haiyi Zhong, Yuzhou Xiang, and Zhang Yanmei
- Subjects
Soil test ,Settlement (structural) ,0211 other engineering and technologies ,Trough (geology) ,Process (computing) ,Excavation ,02 engineering and technology ,Building and Construction ,Deformation (meteorology) ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,Visualization ,Geotechnical engineering ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Civil and Structural Engineering ,Stratum - Abstract
With the increasing demand for transportation infrastructure, the construction of urban tunnel systems linking different areas is indispensable. The deformation and the failure process during a tunnel excavation are essential concerns for geotechnical engineers. However, few studies have systematically investigated the effect of the ground loss ratio on tunnel deformation and the inequality between the ground loss ratio and the volume of the settlement trough. An experimental study using the transparent soil testing technique is performed herein for better visualization and digitization purposes. The three dimensional vertical and horizontal deformation patterns of a single tunnel are investigated for both the surface and the stratum right below considering different ground loss ratios. The relationship among the empirical constant of the settlement trough width, buried depth, depth–diameter ratio, and ground loss ratio is presented.
- Published
- 2022
21. Transient thermal response of a thermally activated pile during a long-term maintained load test at Lambeth College, London
- Author
-
P.J. Bourne-Webb
- Subjects
0211 other engineering and technologies ,02 engineering and technology ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,computer.software_genre ,01 natural sciences ,Test (assessment) ,Term (time) ,Load testing ,Thermal ,Earth and Planetary Sciences (miscellaneous) ,Environmental science ,Geotechnical engineering ,Full scale test ,Transient (oscillation) ,Pile ,computer ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences - Abstract
The energy pile test at Lambeth College, London was first reported just over 10 years ago; however, the original appraisal of the test only looked at the thermal response at the end of extended cooling and heating stages, and did not examine the transient response within these stages or in the daily cyclic thermal loading stage that followed. This paper revisits the earlier results, allowing for concrete creep under sustained load and using a revised strain-dependent pile modulus. The strong influence of the latter and the possible importance of stiffness changes during load reversal is highlighted. Detailed evaluation of the long-term transient results suggests that within a given thermal loading interval the thermal effects are similar, but there is some further discrepancy in the results, possibly due to an underestimation of the concrete creep. This re-evaluation has mitigated pile head displacement and increased thermal stress in the cooling phase, with the reverse occurring in the heating phase, and appears to be in better agreement with back-analysis reported by others. The transient response within the thermal loading stages illustrates that the development of the thermal stress–displacement response is related to the time for heat to diffuse through the pile body – around 3 days in this case.
- Published
- 2022
22. Stability of aqueous Fe(III) chloride complexes and the solubility of hematite between 150 and 300 °C
- Author
-
Nicholas C. Allin and Christopher H. Gammons
- Subjects
Aqueous solution ,010504 meteorology & atmospheric sciences ,Chemistry ,Inorganic chemistry ,Hematite ,010502 geochemistry & geophysics ,01 natural sciences ,Redox ,Chloride ,Ferrous ,Geochemistry and Petrology ,visual_art ,visual_art.visual_art_medium ,medicine ,Ferric ,Solubility ,Dissolution ,0105 earth and related environmental sciences ,medicine.drug - Abstract
Three sets of experiments were performed to test the stability and geologic importance of ferric (FeIII) chloride complexes in acidic, Cl-rich solutions at 150–300 °C, p = psat. Experiment Set A used the change in solubility of AgCl(s) in the presence of FeCl3 or FeCl2 to determine the stoichiometry of Fe(III) and Fe(II) chloride complexes at ΣCl = 0.1–3.0 molal. Results show that FeCl4− and FeCl2(aq) are the dominant Fe(III) and Fe(II) species, respectively, at T > 200 °C and ΣCl ≥ 1 m. Set B experiments used the solubility of elemental gold as a redox sensor to determine the aO2 of the FeCl4−/FeCl2(aq) boundary and log K values of +6.56 and +7.19 for the following reaction at 250 and 300 °C, respectively: FeCl2(aq) + ¼O2(g) + 2Cl− + H+ = FeCl4− + ½H2O(l). Ferric chloride complexes are stable under conditions of aCl−, aO2, and pH where gold is soluble as AuCl2−. Set C experiments measured the solubility of hematite in NaCl-HCl solutions at 200–300 °C by preparing a series of silica tubes with identical matrix chemistry (0.9 m NaCl + 0.1 m HCl) and increasing concentration of FeCl3. Hematite saturation was constrained by the tube with the lowest FeCl3 concentration that precipitated hematite at high temperature. Set C results were used to compute log K values of +3.6, +5.2, and + 7.4 for the following reaction at 200, 250 and 300 °C, respectively: 0.5Fe2O3(s) + 4Cl− + 3H+ = FeCl4− + 1.5H2O. Hematite solubility as FeCl4− is independent of redox state, and increases quickly with an increase in temperature, increase in Cl− concentration (power of 4), and decrease in pH (power of 3). Concentrations in excess of 100 mg/L ΣFe are attainable under geologically realistic conditions. Once formed, FeCl4− is an extremely effective oxidizing agent, capable of destabilizing any sulfide mineral and dissolving Fe, Au, and other metals (e.g., Cu, Pt, Pd) as chloride complexes. In deep hydrothermal systems, FeCl4− is a more viable oxidant than dissolved O2 gas, although its presence requires a source area with abundant hematite and a lack of reductants such as organic carbon, sulfides, or silicate minerals containing ferrous iron. Dissolved ferric chloride could be an important and previously overlooked reactant in the formation of certain types of hematite-rich hydrothermal mineral deposits, including iron oxide-copper–gold (IOCG) deposits.
- Published
- 2022
23. Syn-kinematic sedimentation between ice margin-parallel thrust-bounded ridges of the Glacitectonic Complex of Jasmund (Rügen Island, SW Baltic Sea, Weichselian)
- Author
-
Heiko Hüneke, Michael Kenzler, and Nils Plonka
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Alluvial fan ,Anticline ,Structural basin ,010502 geochemistry & geophysics ,01 natural sciences ,Paleontology ,Thrust fault ,Syncline ,Ice sheet ,Meltwater ,Piggyback basin ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Piggyback basins are common and well-studied features of thrust belts, but they are also known to form in front of advancing ice sheets. However, these glacitectonically developed basins and their syn-glacitectonic fillings have so far received little attention. Here, we present a detailed study of a cliff section on Jasmund peninsula, SW Baltic Sea, where syn-kinematic deposits of Late Weichselian age (MIS2) accumulated in a piggyback basin. Sedimentological analyses, including micromorphology and field studies, resulted in a distinction of at least five tectono-depositional sequences of syn-glacitectonic basin fills. The sediment record indicates a stepwise evolution of the basin, controlled by propagating thrust faults and the resulting thrust-bound ridge morphology. A fast-changing depositional environment with glacifluvial, glacilacustrine, alluvial fan and fan delta depositional systems, show a rapid transformation of the overall morphology of the study area. The main controlling factors are the propagating thrust faults (determining anticline and syncline orientations) and the advancing ice margin, which caused sudden changes or even temporal obstruction of the meltwater drainage system. The proposed stages of basin evolution illustrate the dynamic formation and stepwise syn-tectonic fill of piggyback basins in glacitectonic complexes. Our evolutionary model will increase our understanding of basin fills on glacitectonic thrust- and fold-belts that were formed by approaching ice sheets in ice-marginal settings.
- Published
- 2022
24. The sediment distribution characteristics and transport pattern in the eastern China seas
- Author
-
Xi Mei, Beibei Mi, and Yong Zhang
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Pleistocene ,Terrigenous sediment ,Geochemistry ,Sediment ,010502 geochemistry & geophysics ,Spatial distribution ,01 natural sciences ,Sink (geography) ,Grain size ,Sedimentary depositional environment ,Sediment transport ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
As one of the most important margin seas around the west Pacific, the eastern China seas are important sink for terrigenous materials and forms multiple geology structures. So research the composition and spatial distribution of sediments could help us to understand the dynamics mechanism of the marine sedimentary environment, further to comprehend the land-sea interaction process. Based on high spatial resolution sediment survey in the eastern China seas, the distribution diagram of the sediment types was compiled to reveal the space regularities of sediment. In this study, the Principal Component Analysis (PCA) method was used to identify the controlling factors that are the main controls of the sediment distribution in the study area, which revealed three factors (F1, F2 and –F1) representing grain size categories of >5.75φ, 4.25–5.75φ and 1.50–3.00φ, respectively. F1 represents fine sediments (>5.75φ), -F1 represents coarse sediments (1.50–3.00φ), and F2 represents intermediate-sized sediments (4.25–5.75φ). The sediment transport patterns of the different grain size categories in the eastern China seas are discussed in the context of a comprehensive analysis of sediment grain size composition, material sources, flow patterns, and other factors. The results show that fine-grained sediments represent a “distant” sink of terrigenous material that formed in a stable and low-energy sedimentary environment. The coarse sediment deposits were formed in the late Pleistocene when the hydrodynamic conditions were relatively strong, and the intermediate-sized sediments were distributed in an area with a high concentration of suspension representative of mid-strength hydrodynamic conditions.
- Published
- 2022
25. Stratigraphy of the Late Glacial and Holocene aeolian series in different sedimentary zones related to the Last Glacial maximum in Poland
- Author
-
Paweł Zieliński, Michał Łopuch, Zdzisław Jary, Jacek Skurzyński, Piotr Moska, Konrad Tudyka, Grzegorz Poręba, Agnieszka Szymak, Jerzy Raczyk, Robert J. Sokołowski, and Marcin Krawczyk
- Subjects
010506 paleontology ,Oldest Dryas ,Older Dryas ,010502 geochemistry & geophysics ,01 natural sciences ,Allerød oscillation ,Paleontology ,Preboreal ,Aeolian processes ,Glacial period ,Younger Dryas ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Lateglacial and Holocene sandy aeolian sequences with palaeosol horizons located in different sedimentary zones in western-central Poland were analysed in order to establish their regional stratigraphical and palaeoenvironmental significance. Results of sedimentological, geomorphological and absolute dating methods from 3 representative profiles from an extraglacial zone (Leszczyca site), a glaciomarginal zone (Barczyglow site) and a glaciated zone (Godzieba site) are presented. A compilation of 31 luminescence dates from aeolian sands and 7 14C-dates from palaeosols formed the basement for establishing the stratigraphic position of the analysed deposits. The obtained results were correlated with reference to Greenland ice-core chronology, which has the best resolution for the Northern Hemisphere. In the extraglacial zone, aeolian deposition started in the Oldest Dryas and continued throughout the Older Dryas (main phase of dune built) with limited deposition in the Younger Dryas and finished in Preboreal. Aeolian deposition was interrupted by pedogenic processes in the Bolling and Allerod interstadials as well as in the Younger Dryas-Preboreal transition. Whereas in the glaciomarginal zone aeolian deposition started in the Younger Dryas and continued to the Early Boreal with a weakly expressed pedogenic process in the Early Preboreal. In the glaciated zone, aeolian deposition took place in the Younger Dryas. At the Barczyglow and Godzieba sites palaeosols of the Roman Period and 19th century were detected, covered by aeolian sands. The Subatlantic aeolian episodes were induced by human activity and registered forest fires. Identified periods of aeolian activity and pedogenic processes were correlated with other profiles from central and western Europe.
- Published
- 2022
26. The solubility of thorium in carbonate-bearing solutions at hydrothermal conditions
- Author
-
Anthony E. Williams-Jones, Haylea Nisbet, Hongwu Xu, Vincent J. van Hinsberg, Artas Migdisov, and Robert Roback
- Subjects
Aqueous solution ,010504 meteorology & atmospheric sciences ,Chemistry ,Ligand ,Inorganic chemistry ,Thorium ,chemistry.chemical_element ,010502 geochemistry & geophysics ,01 natural sciences ,Mineralization (biology) ,Hydrothermal circulation ,chemistry.chemical_compound ,Geochemistry and Petrology ,Stability constants of complexes ,Carbonate ,Solubility ,0105 earth and related environmental sciences - Abstract
Thorium mineralization is frequently hosted in carbonate-bearing rocks, and thorium commonly substitutes into the structures of carbonate-bearing minerals that have precipitated from or been modified by hydrothermal fluids. Given this common association, it is reasonable to consider the hypothesis that the presence of carbonate ligands in hydrothermal solutions promotes the transport of Th through the formation of stable aqueous complexes. Our ability to evaluate this hypothesis, however, is hindered by the lack of experimental data for Th-carbonate species at conditions beyond ambient. The low-temperature data indicate that carbonate is a strong complexing agent for Th. In this contribution, we investigate the solubility of Th in carbonate-bearing fluids relevant to natural systems (0.05–0.5 m NaHCO3/Na2CO3; pHT ~ 7.8–9.8) at elevated temperature (175–250 °C). We demonstrate that, in contrast to the behavior of Th at low temperature, the stability of Th-carbonate complexes is not sufficient for them to predominate at these conditions. Instead, the solubility of Th is governed by hydrolysis reactions. Under the experimental conditions investigated, the predominant hydroxyl complexes are Th(OH)40 and Th(OH)5−. Thermodynamic formation constants were derived for these species at the temperatures considered in our experiments (log β4 = 43.34 and 44.31 at 175 and 200 °C, respectively, and log β5 = 46.15 and 47.9 at 225 and 250 °C, respectively) to permit forward modeling of Th mobility in natural systems. Our study indicates that carbonate ions are unlikely to play a role in transporting Th in hydrothermal fluids. Summarizing the results of this study and our previous studies of the solubility of Th in hydrothermal fluids, we conclude that SO42− is the primary ligand responsible for the hydrothermal transport of Th.
- Published
- 2022
27. Heavy metals in the 'plastisphere' of marine microplastics: adsorption mechanisms and composite risk
- Author
-
Chenxi Wu, Shaopeng Xu, Danyang Tao, Luoluo Chen, Paul K.S. Lam, Meng Yan, Yuan Liu, Kai Zhang, Yong Wei, and Guijian Liu
- Subjects
Microplastics ,010504 meteorology & atmospheric sciences ,fungi ,Geology ,Particulates ,Plankton ,010502 geochemistry & geophysics ,01 natural sciences ,Partition coefficient ,Metal ,Adsorption ,Environmental chemistry ,Specific surface area ,visual_art ,visual_art.visual_art_medium ,Seawater ,0105 earth and related environmental sciences - Abstract
Heavy metals that are adhered to the surfaces of microplastics in the natural marine environment pose potential threats to marine life. However, little is known about their adsorption mechanisms and composite risks. This study collected seawater, suspended particulate matter (SPM), plankton, and microplastic samples from the waters surrounding Hong Kong, established a method for analyzing 13 heavy metals in the plastisphere, and explored the extrinsic and intrinsic sources of the heavy metals by analyzing natural matrices (seawater, SPM, and plankton) and anthropogenic plastics. We found that heavy metals in the plastisphere were significantly affected by the surrounding matrices, as indicated by its positive correlations with the heavy metals in SPM and plankton at most of the sampling sites. Heavy metals in plankton usually occurred as traces of oxides such as As2O3 and ZnO. The partition coefficients of the studied heavy metals between seawater and the plastisphere were identical to those between the SPM and the plastisphere. No correlations were found between the concentrations of heavy metals in the plastisphere and the heavy metal concentrations, masses, quantities, or surface areas of the microplastics, although some polymer types contained extremely high Cd (676 mg/kg), Pb (1,742 mg/kg), and Zn (1,712 mg/kg) concentrations. Only the Cr, Cu, and Ni concentrations were positively correlated with the specific surface area of the microplastics. A cluster analysis showed that Cr, Cu, and Ni were derived from anthropogenic sources, indicating that adventive heavy metals could be adsorbed by plastics with large specific surface areas. We also established a new composite risk assessment method for heavy metals and microplastics that leverages the specific surface areas of microplastics. The assessment results showed that Cd from Tolo Harbor had a strong ecological risk, while As and Cd from the eastern waters off Hong Kong had moderate composite ecological risks.
- Published
- 2022
28. A new mode of mineral replacement reactions involving the synergy between fluid-induced solid-state diffusion and dissolution-reprecipitation: A case study of the replacement of bornite by copper sulfides
- Author
-
Fang Xia, Idowu A. Adegoke, Joël Brugger, Mark A. Pearce, Malcolm P. Roberts, and Artur P. Deditius
- Subjects
Mineral ,010504 meteorology & atmospheric sciences ,Diffusion ,chemistry.chemical_element ,engineering.material ,010502 geochemistry & geophysics ,01 natural sciences ,Copper ,Geochemical cycle ,Atomic diffusion ,chemistry ,Chemical engineering ,Geochemistry and Petrology ,Bornite ,engineering ,Dissolution ,Earth (classical element) ,0105 earth and related environmental sciences - Abstract
Mineral replacement reactions are one of the most important phenomena controlling the geochemical cycle of elements on Earth. In the early years, solid-state diffusion was proposed as the main mechanism for mineral replacement reactions, but over the past 20 years the importance of the coupled dissolution-reprecipitation (CDR) mechanism has been recognized. In the presence of a fluid phase and at low temperatures (e.g.
- Published
- 2022
29. Late Quaternary vegetation shifts and climate change in the sub-alpine belt of the Parvati Valley, Himachal Pradesh, India
- Author
-
Prithavi Singh Rathore, Anjali Trivedi, M. S. Chauhan, Kamlesh Kumar, David K. Ferguson, and Anupam Sharma
- Subjects
Total organic carbon ,010506 paleontology ,geography ,geography.geographical_feature_category ,Drainage basin ,Sediment ,Climate change ,Vegetation ,010502 geochemistry & geophysics ,medicine.disease_cause ,01 natural sciences ,Agronomy ,Total inorganic carbon ,Pollen ,medicine ,Environmental science ,Quaternary ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Pollen, sediment texture, moisture, organic/inorganic carbon content and geochemical analyses of a 1.2m in-depth sediment profile from upper Tundabhuj Lake in the Parvati Valley show that the region supported alpine-scrub vegetation. The forest elements largely consisted of Betula and its broad-leaved allies viz., Quercus, Corylus and Carpinus interspersed with meadow grasses, Asteraceae, Impatiens, etc. under a warm and moderately humid climate from around 17,100 to 14,700 cal yr BP. Additionally, the increase in organic carbon, enrichment of immobile elements (TiO2, Al2O3, Fe2O3) and moderate values of the Chemical Index of Alteration (CIA = ~72) reinforce the warm and moderately humid climate in the catchment. Subsequently, at around 14,700 to 10,600 cal yr BP, an increase in alpine-scrub vegetation dominated by Betula, Corylus and Carpinus was observed. The enrichment of (TiO2, Ni and Cr) and slightly higher CIA values (72–78) indicated relatively more humid conditions than earlier climatic conditions. The climate turned cold and dry between 10,600 and 5400 cal yr BP as deduced from the abrupt reduction in the alpine-scrubs and meadow constituents. During this period immobile elements (Al2O3, TiO2, Fe2O3, and Cr) also decreased. In contrast, mobile elements (CaO, Na2O, Sr, and Ba) increased along with a gradual decrease in CIA (minimum at 42.5 cm) and organic carbon content supporting cold and dry climatic conditions. From around 5400 until ~1600 cal yr BP, the region saw a return of alpine-scrubs and conifers, indicating a relatively warm and humid climate. Increasing CIA values, organic carbon, and concentration of immobile elements also reaffirm relatively warm and humid climatic conditions. In the most recent phase (around 1600 cal yr BP to present), the climate deteriorated as reflected by the depletion of Betula and broad-leaved associates and an increase in dry elements such as Juniperus and Ephedra. The decrease in CIA values, organic carbon and immobile elements (TiO2, Al2O3, and Fe2O3) substantiate this observation.
- Published
- 2022
30. Review of transparent soil model testing technique for underground construction: Ground visualization and result digitalization
- Author
-
Wengang Zhang, Xin Gu, Xuanming Ding, Zhitao Ma, and Wenhan Zhong
- Subjects
Soil model ,0211 other engineering and technologies ,Excavation ,02 engineering and technology ,Building and Construction ,Stress distribution ,010502 geochemistry & geophysics ,Geotechnical Engineering and Engineering Geology ,01 natural sciences ,Civil engineering ,Visualization ,Soil water ,Pile ,Geology ,021101 geological & geomatics engineering ,0105 earth and related environmental sciences ,Civil and Structural Engineering - Abstract
In geotechnical engineering, the transparent soil (also called transparent media) technique is an effective tool for conducting experimental tests and investigating the displacement characteristics and stress distribution of soils. It plays a vital role in the observation of internal soil deformations. This study aims to briefly review the current state of some of the common materials used to formulate transparent soil models and the application of the transparent soil technique to underground construction over the last 20 years. To this end, the basic concepts of transparent soils are introduced. Then, several representative applications of transparent soil in underground construction (i.e., soil deformations induced by the penetration of pile foundations, tunnel excavation-induced movements, and structural responses caused by braced excavations) are presented. Because some research gaps may exist, certain potential research topics are proposed. This review can serve as a guideline for researchers performing experiments using transparent soils.
- Published
- 2022
31. Paleomonsoonal shifts during ∼13700 to 3100 yr BP in the central Ganga Basin, India with a severe arid phase at ∼4.2 ka
- Author
-
Anil K. Gupta, Santosh K. Rai, Shweta Singh, Ajoy K. Bhaumik, Pankaj Kumar, and Suman Rawat
- Subjects
Monsoon of South Asia ,010506 paleontology ,Structural basin ,010502 geochemistry & geophysics ,Monsoon ,Convergence zone ,01 natural sciences ,Arid ,Aridification ,Physical geography ,Precipitation ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Chronology - Abstract
We present a multiproxy record of grain size and stable carbon isotope from the Lilaur lake, Ganga Basin, India to understand the history of lake formation linked to changes in Indian monsoon precipitation during ~13714 to 3073 calibrated year before Present (cal yr BP). A comparison is made between Lilaur lake proxy record with those from other parts of South Asia as well as North Atlantic to understand extent and causes of monsoon variability and its influence on the fauna and flora of the region. Chronology of lake core was constrained using AMS 14C and optically stimulated luminescence (OSL) dates. This study suggests a transition from river to lake during ~5800 to 5189 cal yr BP which is supported by reduced precipitation with weakening of the Indian summer monsoon (ISM). This river to lake transition culminated in a severe arid phase during 4250 to 4050 cal yr BP (4.2 ka event), corresponding to enhanced El Nino activity, southward shift of the Inter-Tropical Convergence Zone, and aridification of India when the ISM was weak.
- Published
- 2022
32. Mapping of large-scale diapir structures at the paleo-ice tongue bed in western Latvia from geophysical investigations and borehole data
- Author
-
Jānis Karušs, Jurijs Ješkins, A. Stūrmane, Kristaps Lamsters, and P. Džeriņš
- Subjects
010506 paleontology ,Outcrop ,Ice stream ,Borehole ,Sediment ,Geophysics ,Diapir ,010502 geochemistry & geophysics ,01 natural sciences ,Ice tongue ,Sedimentary rock ,Electrical resistivity tomography ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This study comprises the investigation of the complex and deformed Late Pleistocene sedimentary sequence in western Latvia composed of sandy sediments that are protruded by large-scale clayey silt diapirs and covered by glaciotectonically disturbed discontinuous patches of the Late Weichselian till. We use detailed measurements by ground-penetrating radar (GPR) and electrical resistivity tomography (ERT) combined with borehole data and sedimentological investigations at the Baltic Sea cliffs to map and characterize the large-scale deformation structures and discontinuous till patches. We distinguish the intriguing and previously not detected characteristics of the spatial distribution pattern of discontinuous till layer represented as elongated, up to 150 m long and up to 50 m wide patches, parallel to the seacoast and perpendicular to the latest ice flow direction. The upper surface of till patches is flat and not inclined in any direction that is partially explainable by the postglacial erosion of the Baltic Ice Lake. The possible locations of diapirs inland are drawn from GPR data. We relate the formation of observed large-scale deformations to subglacial diapirism induced by the ice loading of the advancing Apriķi Ice Tongue: clayey silt sediments become loaded and overpressurized, and flowed upwards intruding into the overlying sandy sediments. The initial deposition and deformation of till layer could have been affected by the diapirism process and preferred accretion of till in inter diapir spaces. We demonstrate that the geophysical methods can greatly supplement traditional geological investigations in the field revealing characteristics of deformed sediment sequences that are not recognizable from the outcrop data only and thus can have significant implications on the interpretation of deformation processes.
- Published
- 2022
33. The thermodynamics of rare earth element liberation, mobilization and supergene enrichment during groundwater-regolith interaction
- Author
-
Mei-Fu Zhou, Anthony E. Williams-Jones, Martin Yan Hei Li, and Hiu Tung Kwong
- Subjects
Supergene (geology) ,010504 meteorology & atmospheric sciences ,Chemistry ,Rare-earth element ,Geochemistry ,Eudialyte ,Weathering ,engineering.material ,010502 geochemistry & geophysics ,Fergusonite ,01 natural sciences ,Regolith ,chemistry.chemical_compound ,Geochemistry and Petrology ,engineering ,Carbonate ,Clay minerals ,0105 earth and related environmental sciences - Abstract
Rare earth elements (REEs) mobilize, fractionate, and are re-distributed during supergene processes, and thus provide a powerful tool with which to quantitatively reconstruct the effects of chemical weathering. Moreover, under certain conditions, the REEs can concentrate to levels in the regolith sufficient to form giant regolith-hosted REE deposits, that are now responsible for much of the World’s production of heavy REEs (HREEs). Understanding the supergene behavior of the REEs is an important first step towards applying the REEs as a geochemical tool and meeting the growing global demand of the REEs. Thermodynamic calculations predict that dissolution of the main REE minerals in REE-rich protoliths, namely synchysite-(Y), gadolinite-(Y), hingganite-(Y), yttrialite-(Y), allanite-(Ce), eudialyte, chevkinite-(Ce), britholite, euxenite and loparite-(Ce), should occur spontaneously during weathering. It therefore follows that a high abundance of these minerals in the protolith implies high mobility of the REEs during weathering and consequently a high potential for the discovery of economic REE resources. Dissolution of apatite is promoted by metamictization or structural distortion and could be also important at low pH. In contrast, some LREE-fluorocarbonate minerals, notably bastnasite-(Ce) and parisite-(Ce), and monazite-(Ce) are likely thermodynamically stable in acidic environments. Thus, they would be preserved in the regolith. Zircon, titanite, aeschynite, fergusonite, and xenotime-(Y) are resistant to acidic dissolution, consistent with their common occurrence as residual minerals. In the cases of the world-class regolith-hosted REE deposits in South China, the groundwater is mildly acidic to circumneutral and carbonate-rich. The REEs are consequently transported dominantly as hydrated cations and carbonate complexes, depending on the pH. The general inheritance of the REE pattern of the regolith groundwater in the clay-sorbed fraction in the regolith indicates that the REEs in regolith are scavenged from the regolith groundwater. Elemental anomalies of specific REEs in the clay-sorbed fraction are very likely caused by an anomalously high REECO3+ fraction in the corresponding regolith groundwater, suggesting a preferential uptake of the REECO3+ complexes by the clay minerals, feasibly by halloysite through intercalation as interlayer complexes. This reaction is expected to be particularly important for the sorption and enrichment of the HREEs in the regolith. Depending on the pH and carbonate concentration of the water, surface complexation on clay minerals or interlayer intercalation particularly in halloysite control the pattern of REE enrichment. Mixing of the regolith groundwater with the alkaline and carbonate-rich aquifer groundwater increases the pH and carbonate concentration and, in turn, affects the ability of the mixed water to transport the HREEs. Interplay of aqueous complexation with the regolith mineralogy significantly affects the REE fractionation and re-distribution during groundwater-regolith interaction.
- Published
- 2022
34. Palaeo-ecological development and interpretation of the macrofauna inventory (Bivalvia and Gastropoda) in marine Eemian deposits at Warnow Bay (NE Germany)
- Author
-
Ulrich C Müller, Jaqueline Strahl, Stefan Meng, Andreas Börner, and Holger Menzel-Harloff
- Subjects
010506 paleontology ,Eemian ,Fauna ,Fluvial ,010502 geochemistry & geophysics ,01 natural sciences ,Oceanography ,Indicator species ,Interglacial ,Sandpit ,Weichselian glaciation ,Bay ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
For the palaeo-ecological development and interpretation of the macrofauna (Bivalvia and Gastropoda) of the Eemian Sea in the southwestern Baltic Sea region (NE Germany), up to date studies and summarising assessments are largely missing. With the main goal of revising the Eemian marine fauna, the authors have undertaken numerous new samplings in recent years. This study begins by focusing on the Warnow Bay in today's Warnow valley near Rostock. In addition to examining older data from the literature, the sandpit at Schwaan and drillings of the State Geological Survey from Boitin, Reez and Rostock were studied. Parallel to this, was also undertaken pollen analyses. Despite hundreds of drillings from the region of the former Warnow Bay, evidence of the marine Eemian was relatively rare. Apparently the sandy sediments were reworked and redistributed by glaciotectonic, glaciofluvial and fluvial processes during the Weichselian glaciation. There is as yet no definite proof of autochthonous marine sediments. They are predominantly shallow-marine sands several meters thick which are found mostly at a depth of about 30–20 m b.s.l. but more rarely also relatively close to the surface in opencast mining or cliff sections. The sands are rich in marine mollusc fauna of which 29 species have been identified so far and which also include Lusitanian specimens such as Acanthocardia paucicostata, Lucinella divaricata or Polititapes senescens. Account was also taken of accompanying marine fauna such as barnacles and echinoderms. In addition, the sediments contain fresh water molluscs also including the interglacial indicator species Belgrandia germanica.
- Published
- 2022
35. The Lateglacial and Early Holocene vegetation dynamics: New multi-proxy data from the central Belarus
- Author
-
Boris P. Vlasov, Domas Uogintas, Vaida Šeirienė, Gražyna Kluczynska, Miglė Stančikaitė, Žana Skuratovič, Neringa Gastevičienė, Valentina Zernitskaya, Žilvinas Ežerinskis, Justina Šapolaitė, Laura Gedminienė, and Darius Valūnas
- Subjects
010506 paleontology ,Macrofossil ,Vegetation ,010502 geochemistry & geophysics ,01 natural sciences ,Allerød oscillation ,Physical geography ,Glacial period ,Younger Dryas ,Weichselian glaciation ,Geology ,Holocene ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Gyttja - Abstract
Detailed knowledge of the periglacial flora is essential to assess the vegetation dynamics in deglaciated regions of northern and north eastern Europe, previously covered by the ice sheet of the Late Weichselian Glaciation. Therefore, the territory of Belarus, which stretches in the periglacial zone of the Last Glaciation and the most part of which was free of ice during the Last Glacial maximum, is off particular importance in analysing the postglacial floral establishment and the subsequent vegetation dynamics in this part of the continent. In this study, results of palaeobotanical (pollen and plant macrofossil), lithological (measurements of magnetic susceptibility, MS) and isotopic (14C) investigations were obtained to fill the existing gap in reconstructing the peculiarities of the terrestrial and aquatic vegetation dynamics throughout the Lateglacial - Early Holocene period in the central Belarus. The investigated sediment profile, comprising organically enriched gyttja at 13,400–13,100 cal yr BP, carbon enriched and sandy gyttja at 13,100–9700 cal yr BP and unconsolidated mud after 9500 cal yr BP, provides clear evidence proving the flourishing of a pine-birch predominated forest with occasional spruce stands during the Allerod in area. Three occasions of change in the vegetation structure were noted within the Younger Dryas, i.e. 12,900–12,700 cal yr BP, 12,200–12,000 cal yr BP and 11,900–11,700 cal yr BP, suggesting negative climatic excursion taken place in area and facilitating flourishing of a Picea-predominating forest that culminated at about 12,300 and 12,000 cal yr BP. Pollen record suggests the Early Holocene vegetation shifts occurring at about 11,300–11,200 cal yr BP, 10,800–10,600 cal yr BP and 10,300–10,100 cal yr BP evidence the general response to the global-scale climatic events i.e. Preborael Oscillation or “10,2 ka” while fluctuations triggered by local or regional-scale climatic events have been identified as well. About 10,800–10,700 cal yr BP, formation of the forest with an increasing representation of thermophilous taxa (Ulmus, Tilia, Quercus) started in area.
- Published
- 2022
36. Polygenesis of loamy soils in North-West Siberia in the context of environmental history of the Eurasian Artic region during the Late Quaternary
- Author
-
Andrey Yurtaev, Alexander S. Pechkin, Sergey Sedov, Lilit Pogosyan, Vladimir Sheinkman, Sofia N. Lessovaia, and Alexey Rusakov
- Subjects
Marine isotope stage ,010506 paleontology ,Pleistocene ,Earth science ,Solifluction ,010502 geochemistry & geophysics ,01 natural sciences ,Paleosol ,Pedogenesis ,Stadial ,Quaternary ,Holocene ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This research provided a model of genesis of soils in North-West Siberia connecting the stages of their development to the main environmental changes over the Late Pleistocene and the Holocene. The “soil memory” showed that the studied soils had a complex polygenetic origin. A gleyed paleosol with signs of solifluction found at a depth of 2 m was most probably formed during the Marine Isotope Stage (MIS) 3 that is the Karginsky interstadial. The following stage, i.e., MIS2 – the Sartanian cryochron was characterized by the eolian sedimentation of silty material. In the Late Sartanian, new soil formation began in the silty parent material, with a strong platy cryogenic aggregation and grain size sorting. The warmer and more humid climate in the early Holocene induced clay illuviation and allowed for the formation of the argic horizon. Finally, the modern climatic conditions have caused ooidal cryogenic aggregation within upper horizons, however recent frost action has not been as strong as it was during the previous cold stage. Additionally, the modern pedogenesis included spodic and stagnic processes as well as clay mineral transformation. We suppose that such a model of soil evolution could be extrapolated to the northern Cis-Ural region, but not to the west in the Baltic region, where the dynamics of pedogenesis were different.
- Published
- 2022
37. Characterization of storm surge deposits along the shore of the Gulf of Gdańsk (Baltic Sea) applying heavy mineral analysis
- Author
-
Przemysław Mroczek, Witold Szczuciński, and Damian Moskalewicz
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Heavy mineral ,Coastal plain ,animal diseases ,Sorting (sediment) ,Geochemistry ,Storm surge ,Storm ,010502 geochemistry & geophysics ,01 natural sciences ,Sedimentary depositional environment ,Sedimentary rock ,Overwash ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Recent studies along the southern Baltic Sea coast have revealed sedimentary records of catastrophic storm surges that significantly exceed the magnitude of storms documented by instrumental measurements. The present study aimed to apply heavy mineral analysis for storm surge deposits along coasts of Gulf of Gdansk (southern Baltic), as well as for contemporary marine, beach, dune and coastal plain sediments, to test the applicability of the method and to provide new insights into the depositional processes and sediment sources of the storm deposits. The transparent, 0.125–0.25 mm heavy mineral fraction (>2.85 g/cm3) in 118 sediment samples was investigated, and the results were subjected to multivariate statistical analyses (cluster, PCA, LDA). Storm deposits showed higher concentrations of heavy minerals comprising enrichment in garnet, zircon, and rutile. General heavy mineral assemblage depended on regional provenance and primary sediment sources. However, flooding regime (overwash or inundation) played a key role in selective hydrodynamic sorting of grains and mineralogical composition of storm deposits. Interpretation of deposits formed in inundation regime was more certain than deposits formed in overwash regime. In the latter case, deposits showed more similarities to adjacent mineral provinces. Statistical analyses proofed that heavy minerals together with other sedimentological descriptors may be a promising proxy for recognition of deposits related to defined sedimentary environment or identification of particular sedimentological process, e.g. event layers resulted from storm surges.
- Published
- 2022
38. Luminescence dating of a dammed lake formed by Ashegong landslide on the northeastern Tibetan Plateau
- Author
-
Jiuchuan Wei, Zhaojun Song, and Xiaohua Guo
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Plateau ,Optically stimulated luminescence ,Thermoluminescence dating ,Landslide ,010502 geochemistry & geophysics ,01 natural sciences ,Isotopes of oxygen ,Tectonic uplift ,Tributary ,Physical geography ,Stage (hydrology) ,Geology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
A landslide, Ashegong, blocked the Garang River, a tributary of the Yellow River on the northeastern Tibetan Plateau. Six optically stimulated luminescence (OSL) samples were collected from ~35-m-thick lacustrine sediments of the landslide-dammed lake deposited on the bank of Garang River in this study. Samples yielded 40.3 ± 2.7 ka at the top of the lacustrine section and 21.8 ± 1.4 ka at the base of lacustrine layer, which indicated that the dammed lake last approximate 18.5 ka. This landslide dammed lake forming at 40.3 ± 2.7 ka, appeared to be associated with the wetter conditions and extensive rainfall affected by paleomonsoon during marine oxygen isotope stage (MIS) 3 on the northeastern Tibetan Plateau. The blockage by Ashegong landslide had a vital role in shaping river network such as causing the river diversion. Understanding the geomorphic process of landslide damming event is benefit for reflecting paleoclimatic change, tectonic uplift, forecast and mitigate hazards in mountainous area.
- Published
- 2022
39. Reconstruction of pre-monsoon relative humidity since 1800 C.E. based on tree-ring data of Pinus roxburghii Sarg. (chir–pine) from Pithoragarh, Western Himalaya
- Author
-
Rupesh Dhyani, Rajesh Joshi, P. S. Ranhotra, Amalava Bhattacharyya, Shyamal K. Nandi, Mayank Shekhar, Shinny Thakur, and Ashish K. Pal
- Subjects
010506 paleontology ,biology ,Global warming ,Climate change ,Subtropics ,010502 geochemistry & geophysics ,Atmospheric sciences ,biology.organism_classification ,01 natural sciences ,Pre monsoon ,Tree (data structure) ,Environmental science ,Relative humidity ,Tree ring data ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Pinus roxburghii - Abstract
Relative humidity (RH), an important climatic element influencing tree growth, is also crucial in assessing the General Circulation Models (GCMs) on global warming. However, in the absence of a relatively long record of RH in the Himalayan region, precise modelling of the climate change related processes and their impacts on this region are not well established. Here we present a new RH reconstruction for the pre-monsoon months (February–May) starting from 1800 C.E. using the tree-ring width data of subtropical Pinus roxburghii (chir-pine) from Pithoragarh, Western Himalaya, India. We found significant positive correlation between tree growth and pre-monsoon RH (n = 67, r = +0.569, p
- Published
- 2022
40. Evolution of sediment provenances and transport processes in the central Bay of Bengal since the Last Glacial Maximum
- Author
-
Xisheng Fang, Wenxing Ye, Xuefa Shi, Peng Cao, Somkiat Khokiattiwong, Hui-Juan Pan, Shengfa Liu, Jingrui Li, Dejiang Fan, Xiaoyan Li, Hui Zhang, and Narumol Kornkanitnan
- Subjects
010506 paleontology ,geography ,geography.geographical_feature_category ,Continental shelf ,Terrigenous sediment ,Sediment ,Last Glacial Maximum ,Submarine canyon ,010502 geochemistry & geophysics ,01 natural sciences ,Deposition (geology) ,Oceanography ,Sedimentary rock ,Geology ,Sea level ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
To investigate the evolution of sediment provenances and transport processes in the central Bay of Bengal (BoB) since the Last Glacial Maximum, we present a comprehensive study on the grain size, clay minerals, rare earth elements, and accelerator mass spectrometry (AMS)14C analyses of the core BoB-24 sediments. Six AMS14C dates were obtained from planktonic foraminiferal Neogloboquedrina dutertrei (N. dutertrei) extracted from the core to reconstruct a reliable age model. The assemblage of clay minerals and the (La/Yb)UCC–δEu relationship indicated that the core contained a mixture of sediments from the Himalayas and Indian Peninsula. These results showed that the Himalayas were the main source of erosional materials during 25–6.5 ka BP, whereas those from the Indian Peninsula increased since the mid-Holocene. Between 25 ka BP and 12 ka BP, the sea level was relatively low, and a large amount of terrigenous detrital material were directly transported from the Himalayas and the Tibet Plateau to the study area by submarine canyons, forming a deposition center on the Bengal Fan. Between 12 ka BP and 6.5 ka BP, the sea level gradually rose and the Indian summer monsoon gradually strengthened, whereas the sedimentation rate and the amount of material transported from the Ganges–Brahmaputra River decreased greatly; the deposition center transferred from the Bengal Fan to the shelf of the BoB. Since 6.5 ka BP, the sea level has risen, reaching its present position. A high sea level and a strengthened East Indian Coastal Current resulted in an increase of material contribution from India, while the deposition center was on the shelf of the BoB. Overall, this study confirmed that both sea level fluctuations and variations of the Indian summer monsoon controlled the evolution of sediment provenances in the central BoB and transfer of the deposition center from the Bengal Fan to the continental shelf. This typical sedimentary pattern observed in the northeastern Indian Ocean improves our general understanding of past land–sea interactions.
- Published
- 2022
41. The role of birds in Upper Palaeolithic sites: Zooarchaeological and taphonomic analysis of the avian remains from Arbreda Cave (Serinyà, northeast Iberia)
- Author
-
Julià Maroto, Mario Marqueta, Narcís Soler, Lluís Lloveras, Joaquim Soler, and Lluís Garcia
- Subjects
Mediterranean climate ,Biotope ,010506 paleontology ,Taphonomy ,geography.geographical_feature_category ,Environmental change ,Ecology ,Archaeological record ,010502 geochemistry & geophysics ,01 natural sciences ,Grassland ,Geography ,Cave ,Feather ,visual_art ,visual_art.visual_art_medium ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Intensification in the procurement of small game, including different taxa of birds, has been proposed as one of the indicators of dietary shifts occurring in western Mediterranean regions during the Upper Palaeolithic as a consequence of both increased human hunting pressures and environmental change. In this paper, avian remains recovered from the Upper Palaeolithic levels of Arbreda Cave (Serinya, northeast Iberia) are analysed. Our results evidence a high diversity of bird taxa in most levels, with the presence of a minimum of 50 species, including birds that inhabit a variety of biotopes such as cliffs, rivers and wetlands, and open grassland, along with coniferous and mixed forests. Taphonomic analysis of the bird bones from all levels indicates a mixed origin for the material, humans being one of the agents responsible for the accumulations. The results show that birds were caught for consumption. However, wing feathers and phalanges were also extracted, probably for ornamental or ceremonial purposes. A significant number of tooth/beak-marked bones and digested remains also evidence the participation of different species of raptors and, to a lesser degree, of small terrestrial carnivores in creating these assemblages. Finally, some birds died naturally and were then incorporated into the archaeological record. This study contributes to the discussion of the importance of the exploitation of birds by hunter-gatherers during the Upper Palaeolithic in the region.
- Published
- 2022
42. Goose in the hole! A collection of goose bones from a medieval kiln site in Norfolk
- Author
-
Antony R.R. Mustchin and Julia E.M. Cussans
- Subjects
010506 paleontology ,Geography ,Goose ,Medullary cavity ,biology ,Kiln ,biology.animal ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
A large collection of goose bones was recovered from excavations at Wheatcroft Farm, Bradwell, Norfolk. The goose bones were of particular interest due to the large quantity present and the presence of medullary bone in some of the specimens. All of the goose bones derived from two 11th-12th century contexts found in close association with a grain drying kiln and related sunken structure. The majority of the bones came from a single posthole. Evidence from body part representation, butchery marks and the occurrence of medullary bone is examined. Domestic geese are common on medieval sites in England and the element distribution and butchery marks are suggestive of waste from carcass preparation for cooking, with the meatiest elements largely having been removed. It seems possible that goose ‘crowns’ were being prepared and then cooked in or close to the kiln. The presence of medullary bone is unusual due to the more seasonal laying behaviour of geese compared to chickens and is examined in detail.
- Published
- 2022
43. The role of birds in the Chalcolithic: The avian material culture from the late fifth millennium BCE in the Southern Levant
- Author
-
Ben Greet
- Subjects
010506 paleontology ,History ,Sculpture ,Southern Levant ,Context (language use) ,Chalcolithic ,Ancient history ,010502 geochemistry & geophysics ,01 natural sciences ,Ossuary ,Sherd ,Pottery ,Iconography ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
There is an inherent contradiction in the position of birds within the Ghassulian culture of the Late Chalcolithic Southern Levant. Whilst they are almost completely absent from the zooarchaeological record, they appear as the second most common animal representation within Ghassulian iconography, with only caprids appearing more often. This has led some scholars to posit that birds played a significant role within the spiritual life of the Chalcolithic. This paper will re-examine this avian iconography, through a collation, exploration, and re-evaluation of each object, emphasising their specific context and integrating their interpretation with both biological/ecological and/or zooarchaeological evidence where possible. Through this type of examination, we can not only shed light on the meaning of these avian images, but hopefully on the role of birds within the societies of the Late Chalcolithic. The study collates and examines each piece of avian material culture uncovered from the Late Chalcolithic: the bird fresco from Building 78 and a painted pottery sherd, both found at Teleilat Ghassul; the avian standard, ‘crown’ no. 7, and the decorated horn-like vessels from Nahal Mishmar; the ritual ostrich egg deposits from Gilat; a possible bird sculpture on an ossuary; bird-shaped ivory pins from Abu Matar and Shiqmim; the bird-shaped vessels from Palmahim; and two unstratified objects: a vessel with sculpted birds on the rim and two avian sculptures. Due to the ritual function and/or context of this avian material culture, it is clear that avian imagery had meaning within Ghassulian spiritual thought. Previous scholars have linked this to an Inanna-like fertility deity, but the objects do not provide enough evidence for this connection. Instead, through historical and ethnographic parallels, I propose a more abstract interpretation of these avian images as symbols of spiritual liminality, i.e. crossing the boundary between the mortal and the spiritual.
- Published
- 2022
44. Fowling on the banks of the Scheldt river in the recent Neolithic (France, 3300-2900 cal BC)
- Author
-
Gilles Leroy, Pierre Gil Salvador, and Tarek Oueslati
- Subjects
010506 paleontology ,biology ,Fauna ,Subsistence agriculture ,Context (language use) ,Excavation ,010502 geochemistry & geophysics ,biology.organism_classification ,01 natural sciences ,Archaeology ,Geography ,Waterfowl ,Palaeochannel ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
The site of Bouchain is the first recent Neolithic site excavated in northern France. The four excavation campaigns have revealed an activity zone on the bank of a palaeochannel of the Scheldt river. The fauna comprising 1892 bone remains buried in a waterlogged sediment is very well preserved revealing surface modifications including cutting, breakage and cooking. Wild mammals and birds are important components of the subsistence strategy summing up to 43% of vertebrate remains. Fowling constitutes 15% of exploited wild resources with a focus on waterfowl, primarily mallard. No equivalent pattern of fowling could be found in the final Neolithic nor in the middle Neolithic sites of the regional context. The closest subsistence strategies to the one of Bouchain was found in the Netherlands within contemporaneous sites where hunting for mammals and waterfowl played a major role in the diet.
- Published
- 2022
45. Worked goose radii from medieval England: What were they used for?
- Author
-
Lena Strid
- Subjects
010506 paleontology ,Goose ,Geography ,biology ,biology.animal ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
This paper examines an artefact type of unknown function, found in several places across medieval England. These artefacts are mostly made from goose radii, but other species, such as chicken and hare, are also known. The worked radii have often been interpreted as being related to writing, but a closer examination suggests that they are more likely to be awls.
- Published
- 2022
46. Bird exploitation from the epigravettian site of Riparo Dalmeri (Trento, Italy)
- Author
-
Antonio Tagliacozzo, Monica Gala, Ivana Fiore, Rossella Duches, and Giampaolo Dalmeri
- Subjects
Stone tool ,010506 paleontology ,Taphonomy ,Resource (biology) ,Epigravettian ,engineering.material ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,Geography ,engineering ,Assemblage (archaeology) ,Rock shelter ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Riparo Dalmeri is an Epigravettian high altitude rock shelter, seasonally occupied for specialized ibex hunting. Its occupation pattern indicates the mobility of human groups from the lowlands to the mountains, in order to exploit a territory which is inaccessible during the winter. This work presents the results of the taphonomic study carried out on the bird bone assemblages from Riparo Dalmeri, where birds play a secondary role as an economic resource, when compared to the intense seasonal exploitation of ibex. Despite its small size, the bird bone assemblage still provides valuable ecological information as well as information about anthropic traces connected with food exploitation and other resources. The most common human modifications detected on the bird bones are those related to butchery: stone tool cut-marks, fresh bone fracture, peeling, crushing, wrenching, and, more rarely, notches or chop-marks. Localized burning traces have also been detected.
- Published
- 2022
47. The Bronze Age birds in Greece. A zooarchaeological perspective
- Author
-
Dimitra Mylona
- Subjects
010506 paleontology ,Geography ,Osteology ,Bronze Age ,Perspective (graphical) ,Period (geology) ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Bird bones are rare finds in Bronze Age excavations in Greece, though, the presence of bird representations in art of the same period is remarkable. This paper examines this paradox from a zooarchaeological perspective. It records and presents the osteological evidence for bird exploitation by Bronze Age communities in Greece and examines the characteristics of the bird bone assemblages, emphasizing the need for nuance and methodological rigor in interpreting these data. This evidence is then viewed against the contemporary birds’ representations record from the same area. From such a comparative approach, a number of similarities and differences emerge regarding the intensity of human-bird interactions, the preferred bird types or the significance of particular types of birds across the study area. Further study of these discrepancies may offer a better understanding of the role of birds in Bronze Age Aegean.
- Published
- 2022
48. Bird exploitation in Viljandi (Estonia) from the Late Iron Age to the early modern period (c. 950–1700)
- Author
-
Freydis Ehrlich, Eve Rannamäe, and Heiki Valk
- Subjects
010506 paleontology ,education.field_of_study ,Population ,010502 geochemistry & geophysics ,01 natural sciences ,Prehistory ,Geography ,Hawking ,Habitat ,Early modern period ,Period (geology) ,Ethnology ,Rural settlement ,education ,0105 earth and related environmental sciences ,Earth-Surface Processes ,Social status - Abstract
This paper examines archaeological bird bones from Viljandi – one of the strongest centres in prehistoric and medieval Estonia – and covers material from the Late Iron Age to Early Modern Period, c. 950–1700. Over 5000 bird bones were analysed in this study. Our main aim was to explore the role of birds in people's diet and its relevance to social status, but also to explore the birds' habitats and environmental background, including commensalism and seasonal occurrence. This study highlighted differences between the four areas of Viljandi – the prehistoric rural settlement, historic castle, town, and suburb. We discuss diachronic trends in the utilisation of birds in these areas, largely determined by the 13th century Baltic Crusades and the transition from the Prehistoric to the Middle Ages, but also by population expansion and the social divergence that followed. In Prehistory, we witnessed more chicken exploitation, while wild birds seem to have played a smaller role. In the Historic Period, on the contrary, the utilised species are more diverse – probably to manifest social status. The main use of birds was for meat, eggs, and other products. Some species might have been used for hawking.
- Published
- 2022
49. Birds as status symbols in northern France: Boves Castle during the High Middle Ages, in its regional context
- Author
-
Benoît Clavel, Colin Duval, Cités, Territoires, Environnement et Sociétés (CITERES), Centre National de la Recherche Scientifique (CNRS)-Université de Tours (UT), Archéozoologie, archéobotanique : sociétés, pratiques et environnements (AASPE), Muséum national d'Histoire naturelle (MNHN)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Université de Tours
- Subjects
010506 paleontology ,geography.geographical_feature_category ,[SHS.ARCHEO]Humanities and Social Sciences/Archaeology and Prehistory ,Feature (archaeology) ,Status symbol ,[SHS.ANTHRO-BIO]Humanities and Social Sciences/Biological anthropology ,Excavation ,Wetland ,Context (language use) ,Consumption (sociology) ,010502 geochemistry & geophysics ,01 natural sciences ,Archaeology ,Geography ,Middle Ages ,ComputingMilieux_MISCELLANEOUS ,0105 earth and related environmental sciences ,Earth-Surface Processes - Abstract
Boves Castle, located in northern France, was occupied between the 9th and 16th centuries AD. Under excavation since 1996, this high-status site has yielded more than six tons of faunal remains. Until now, archaeozoological studies have focused on the early occupation of the site (10th and 11th centuries AD), revealing specific supply and consumption strategies, widely based around birds. Aside from the very large amount of domestic fowl, Boves Castle is distinguished by the number and diversity of wild birds from various environments, including wetland, coastal, forested and anthropized areas. However, the special feature of this site is the importance of freshwater birds, especially large waders, which remained a status symbol until modern times in this region. On the basis of this outstanding example, and other high-status sites from the same region, we aim to discuss the importance and status of various domestic and game bird categories in northern France during the High Middle Ages. We will also address the subject of controlled hunting areas around castles and other high-status consumer sites, for a better understanding of the link between power and consumption during the medieval period.
- Published
- 2022
50. Sparse Deconvolution of Pulsatile Growth Hormone Secretion in Adolescents
- Author
-
Elizabeth B. Klerman, Jon Xavier Genty, Natalie D Shaw, Rose T. Faghih, and Rafiul Amin
- Subjects
medicine.medical_specialty ,Adolescent ,010504 meteorology & atmospheric sciences ,Human Growth Hormone ,Applied Mathematics ,Pulsatile flow ,Biology ,010502 geochemistry & geophysics ,01 natural sciences ,Growth hormone secretion ,Basal (phylogenetics) ,Endocrinology ,medicine.anatomical_structure ,Anterior pituitary ,Hypothalamus ,Growth Hormone ,Internal medicine ,Genetics ,medicine ,Humans ,Secretion ,Deconvolution ,0105 earth and related environmental sciences ,Biotechnology ,Hormone - Abstract
Growth hormone (GH) is secreted by cells in the anterior pituitary on two time scales: discrete pulses over minutes that occur within a 24-hr pattern. Secretion reflects the balance of stimulatory and inhibitory inputs from the hypothalamus and is influenced by gonadal steroids, stress, nutrition, and sleep/wake states. We propose a novel approach for the analysis of GH data and use this approach to quantify (i) the timing, amplitude and the number of GH pulses and (ii) GH infusion, clearance and basal secretion (i.e., time invariant) rates, using serum GH sampled every 10 minutes during an 8-hour sleep study in 18 adolescents. In our method, we approximate hormonal secretory events by deconvolving GH data via a two-step coordinate descent approach. The first step utilizes a sparse-recovery approach to estimate the timing and amplitude of GH secretory events. The second step estimates physiological parameters. Our method identifies the timing and amplitude of GH pulses and system parameters from experimental and simulated data, with a median R^2 of 0.93, among experimental data. Recovering GH pulses and model parameters using this approach may improve the quantification of GH parameters under different physiological and pathological conditions and the design and monitoring of interventions.
- Published
- 2022
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.