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This research presents an in-depth analysis of large mammal remains first discovered in 1932 in the archaeological area of ancient Rome, central Italy, during the work for the opening of Via dell'Impero (VFI). This work describes the faunal assemblage, its current preservation status, and uses tephrochronology to assess its age. Additionally, it provides paleoecological insights into the evolution of the mammalian fauna in Latium, central Italy, from MIS 13 to MIS 7. Analysis of the fossils updates the identification previously proposed by De Angelis d'Ossat, confirming the presence of Palaeoloxodon antiquus, Cervus elaphus, and Bos primigenius. However, in contrast to the previous author, the hippopotamus remains are assigned to Hippopotamus cf. antiquus, and a second deer is identified as Dama sp.. Furthermore, gnawing marks on the hippopotamus femur suggest the presence of a middle-sized carnivore. Tephrochronological investigation was conducted on pumice retrieved from the VFI fossiliferous layer and ash extracted from sediments adhering to the fossil surfaces. The major element composition of the glass from all pumice/ash samples shows a strong affinity with the Vico β unit, allowing correlation with the Fucino record and constraining the deposition of the VFI fossiliferous level between <406.5 ± 1.3 ka and >405.7 + 1.5/−1.6 ka. Radiometric dating is particularly useful for large mammal faunas of MIS 11-MIS 7, a period lacking significant faunal renewals, as Latium mammalian faunas are often dominated by species (elephants, red deer, aurochs) with broad chronological ranges. [ABSTRACT FROM AUTHOR]

Pollen analysis was carried out on the infilling succession of the Fossa San Vito sinkhole, at the NE foothills of the Sarno Plain (Italy). Four 14C dates and six tephra layers constrain the pollen sequence between ca. 6000 and 500 cal yr BP. A forested environment, with a few signs of human activities, characterizes the pre-protohistoric period (ca. 6000–2750 yr BP). Stability of the arboreal pollen grains to non-arboreal pollen grains (AP/NAP) curve is due to climate-related opposite oscillations of deciduous and evergreen forest. In this period, the pyroclastic products from Neapolitan volcanoes that reached the upper Sarno Plain seem to have affected neither vegetation nor human activities. In the archaic and classic periods (ca. 2750–1500 yr BP), intensive deforestation and increase in anthropogenic indicators indicate the occurrence of grazing and crop activities managed by the main urban centers located in the plain: Pompeii, Stabiae, and Nuceria. After the Pompeii eruption in CE 79, a rapid re-afforestation and decline in all anthropogenic indicators testify to the temporary abandonment of the area, linked to the disastrous demise of the main economic centers. The upper plain was repopulated and exploited in the Late Ancient and Middle Ages (ca. 1700–500 yr BP), as indicated by the increase in all crop and grazing indicators. [ABSTRACT FROM AUTHOR]

Volcanic ash (tephra) preserved in terrestrial environments and lake sediments contains information about volcanic processes and can be used to infer eruptive parameters and frequency of past eruptions, contributing to the understanding of volcanic hazards. However, tephra deposits can undergo transformation from their initial fallout sedimentation to being preserved as a tephra layer in the sedimentary record. The process is likely to be different in lakes and in terrestrial (soil) sequences. Here we compare the thickness, mass loading and grain size of tephra layers from the 1991 eruption of Cerro Hudson, Chile, from small lakes and adjacent terrestrial settings to measurements of the tephra made shortly after the eruption. We analysed samples from 35 cores in total from six small lakes (<0.25 km2), located 76 and 109 km from the volcano in two contrasting climatic areas (cool and humid northern site, and warm and dry southern site), and made 73 measurements of tephra thickness and 11 measurements of grain size in adjacent terrestrial areas. The major element geochemistry of our samples confirmed they were from the 1991 Hudson eruption. We found that some of the measured characteristics of the preserved tephra layers were comparable to those recorded in 1991 shortly after initial deposition, but that there was considerable variability within and between locations. This variability was not predictable and lake sediments did not preserve a notably more accurate record of the fallout than terrestrial sites. However, in aggregate the characteristics of the preserved tephra was similar to those recorded at the time of deposition, suggesting that, for palaeotephra research, a sampling strategy involving a wide range of environments is more robust than one that relies on a single sedimentary record or a single type of sedimentary environment. [ABSTRACT FROM AUTHOR]

The Mediterranean region has been characterized by intense explosive volcanism since the Eocene. These eruptions ejected tephra, including fine-grained ash, which were thrown into the air and dispersed over wide areas to later be deposited as ash layers, many of which are preserved in some continental and marine sedimentary basins. Their study provides crucial insights into past volcanic activity, yet, for many of such ash layers, the understanding of their sources remains challenging. The presence of many ash layers across central Italy is widely recognized in literature although not uniquely associated with a specific volcanic source. We investigate in detail upper Tortonian (~ 7.6 Ma) ash layers sampled from three different localities, from the Tyrrhenian to the Adriatic coast of Italy, comparing our results with others already described in the literature. Electron microprobe geochemical analyses on biotite crystals, U–Pb ID-TIMS and LA-ICP-MS geochronological dating, and trace elements/Lu–Hf isotope analyses on zircons permitted us to expand our knowledge of these ancient ash deposits. Several potential volcanic centers were active during the late Tortonian, including the Massif Central (France), the Valencia trough (Spain), the Betics-Rif orogen (Spain-Morocco), and eastern Carpathians (Romania) and Capraia island (Italy). Through detailed radioisotopic dating and geochemical comparisons, we narrow down the possible source to the Upper Miocene Capraia island volcano (Tuscan archipelago), located in the northern Tyrrhenian basin. [ABSTRACT FROM AUTHOR]

Paleogene age deposits east of the Fifteenmile River, northwest of Dawson City, Yukon, Canada preserve a diverse high‐latitude fossil flora. Here, we provide new data on the age of the fossil site based on laser ablation–inductively coupled plasma–mass spectrometry (LA‐ICP‐MS) U‐Pb dating of tephra zircons, paleobotanical paleoclimate reconstructions, and growing season length estimates based on photoperiod. These new data indicate an age of the Fifteenmile River fossil locality as late middle Eocene and likely within the Middle Eocene Climatic Optimum episode. The paleoflora‐based paleoclimate reconstruction indicates the region was relatively wet and warm with non‐freezing winters, but also experienced seasonal dryness, with an approximate 7 months long growing season as suggested by photoperiod. We interpret this paleoclimate as summer dry and winter wet—a climate analogous to modern day warm Mediterranean climates in the Köppen‐Geiger climate classification system. These findings provide a new perspective on the past climate and environment of high‐latitude ecosystems during warm greenhouse intervals and contribute to our understanding of the Earth's climate history and its potential future changes. Key Points: New U‐Pb data show the Fifteenmile River fossil flora age is late middle Eocene, potentially within the Middle Eocene Climatic OptimumWest central Yukon had a warm Mediterranean climate, with wet, mild winters and a distinct summer‐dry season during the late middle EoceneGrowing season length at high latitudes during greenhouse intervals would be determined by photoperiod, not temperature [ABSTRACT FROM AUTHOR]

The obituary in the journal "Radiocarbon" commemorates the life and work of Mike Baillie, a Belfast-born scientist known for his contributions to dendrochronology and radiocarbon dating. Baillie's research focused on building oak and pine tree-ring chronologies in Ireland, which became the basis for radiocarbon calibration curves. He also explored the environmental impacts on trees and societies, suggesting links between narrow-ring events and volcanic dust or cosmic origins. Baillie's meticulous work and interdisciplinary approach left a lasting legacy in the fields of science, archaeology, and history. [Extracted from the article]

The analysis of tephra layers in maar lake sediments of the Eifel shows 14 well-visible tephra during the last glacial cycle from the Holocene to the Eemian (0–130,000 yr b2k). These tephra were analyzed for their petrographic composition, which allows us to connect several tephra to eruption sites. All tephra were dated by application of the ELSA-20 chronology, developed using the late Pleistocene infilled maar lake of Auel and the Holocene lake Holzmaar (0–60,000 yr b2k). We extend the ELSA-20 chronology with this paper for the millennia of 60,000–130,000 yr b2k (ELSA-23 chronology), which is based on the infilled maar lake records from Dehner, Hoher List, and Jungferweiher. The evaluation of the tephra from the entire last glacial cycle shows that all 14 tephra were close to interstadial warming of the North Atlantic sea surface temperatures. In particular, phreatomagmatic maar eruptions were systematically associated with Heinrich events or C-events. These events represent times of warming of the Southern Hemisphere, global sea level rise, and CO2 increase, which predate the abrupt interstadial warming events of the Northern Hemisphere. This synchroneity indicates a physical relationship between endogenic and exogenic processes. Changes in the lithospheric stress field in response to changes in continental ice loads have already been suggested as a potential candidate to explain the exogenic forcing of endogenic processes. The chronology of volcanic activity in the Eifel demonstrates that intraplate mantle plumes are also affected by the exogenic forcing of endogenic processes. [ABSTRACT FROM AUTHOR]

Volcanic ash (tephra) preserved in terrestrial environments and lake sediments contains information about volcanic processes and can be used to infer eruptive parameters and frequency of past eruptions, contributing to the understanding of volcanic hazards. However, tephra deposits can undergo transformation from their initial fallout sedimentation to being preserved as a tephra layer in the sedimentary record. The process is likely to be different in lakes and in terrestrial (soil) sequences. Here we compare the thickness, mass loading and grain size of tephra layers from the 1991 eruption of Cerro Hudson, Chile, from small lakes and adjacent terrestrial settings to measurements of the tephra made shortly after the eruption. We analysed samples from 35 cores in total from six small lakes (

This research presents an in-depth analysis of large mammal remains first discovered in 1932 in the archaeological area of ancient Rome, central Italy, during the work for the opening of Via dell’Impero (VFI). This work describes the faunal assemblage, its current preservation status, and uses tephrochronology to assess its age. Additionally, it provides paleoecological insights into the evolution of the mammalian fauna in Latium, central Italy, from MIS 13 to MIS 7. Analysis of the fossils updates the identification previously proposed by De Angelis d’Ossat, confirming the presence of Palaeoloxodon antiquus, Cervus elaphus, and Bos primigenius. However, in contrast to the previous author, the hippopotamus remains are assigned to Hippopotamus cf. antiquus, and a second deer is identified as Dama sp.. Furthermore, gnawing marks on the hippopotamus femur suggest the presence of a middle-sized carnivore. Tephrochronological investigation was conducted on pumice retrieved from the VFI fossiliferous layer and ash extracted from sediments adhering to the fossil surfaces. The major element composition of the glass from all pumice/ash samples shows a strong affinity with the Vico β unit, allowing correlation with the Fucino record and constraining the deposition of the VFI fossiliferous level between 405.7 + 1.5/−1.6 ka. Radiometric dating is particularly useful for large mammal faunas of MIS 11-MIS 7, a period lacking significant faunal renewals, as Latium mammalian faunas are often dominated by species (elephants, red deer, aurochs) with broad chronological ranges.

In the lacustrine succession F4‐F5 of the Fucino Basin, central Italy, 20 visible tephra layers were identified in the time interval 250–315 ka (Marine Isotope Stages 8–9). Fifteen of them contained suitable material to explore their volcanic sources. Among these tephra some well‐known eruptions and eruptive sequences of the Roman and Roccamonfina volcanoes were identified, such as the Tufo Giallo di Sacrofano and the Lower White Trachytic Tuff, respectively. Furthermore, the sediment succession documents a more complex eruptive history of the Sabatini, Vulsini, Colli Albani and Roccamonfina volcanic complexes during the investigated period, as inferred from previously undescribed tephra deposits. Single‐crystal‐fusion 40Ar/39Ar dating of two of the inspected tephra layers combined with two already published tephra ages provided the basis for a Bayesian age‐depth model. The modelled tephra ages allow chronological constraining of so‐far undefined eruptions of the Sabatini (272.5±4.7, 281.8±4.7, 308.5±2.8, 312.8±2.1 ka), the Vulsini (311.7±2.3, 311.9±2.3 ka) and the Colli Albani (301.0±3.6 ka) volcanic districts. Two tephra layers of an undefined volcanic source from the Roman volcanoes have modelled ages of 309.5±2.7 and 310.5±2.6 ka. The new 40Ar/39Ar and modelled ages were further used for a reassessment of the timing of already known and dated eruptive units, such as the Tufo Giallo di Sacrofano (40Ar/39Ar: 289.3±4.8 ka). Tephra tentatively correlated with the Valle Santa Maria, Case Pisello and the White Trachytic Tuff Unit E3 or Unit F offer modelled ages for these eruptions of 296.6±3.9, 301.8±3.5 and 303.6±3.4 ka, respectively. The results complete the tephrostratigraphical investigations of the c. 425 ka old F4‐F5 record, extend the Mediterranean tephrostratigraphical framework and provide a significant contribution for improving knowledge on Italian volcanic explosive activity. [ABSTRACT FROM AUTHOR]

On the border of China and North Korea, there is the only active stratovolcano in the eastern part of Asia: Mount Paektu (other names are Baitoushan and Changbaishan). It is widely known for one of the largest eruptions in the historical era, which occurred in the 10th century AD. On the volcanic-activity scale, the event is rated at seven points, this is the largest eruption in the last millennium. Modern research shows that the eruption of the Paektu volcano occurred in late autumn–winter 946 AD. This dating is supported by data obtained from the study of an ice core from North Greenland, in which traces of volcanic ash were found. At a depth of 860 mm (the age according to the calculation of annual layers is 942 AD ± 26 years), a layer 2–3 mm thick was found, which differed sharply in color and texture from the rest of the core material. Using a module of confocal X-ray microscopy, an optical section containing an anomalous layer was studied. 2D scanning with a focused beam of synchrotron radiation 20 µm in diameter was carried out. A large amount of microparticles with a high content of zirconium and yttrium was found inside the layer. The possibility of finding traces of the eruption of the Paektu volcano is discussed. [ABSTRACT FROM AUTHOR]

We present a continuous ∼6.2 Ma long record of explosive activity from the Northwest Pacific volcanic arcs based on a composite tephra sequence derived from Ocean Drilling Program Sites 882A and 884B, and core MD01‐2416 on the Detroit Seamount. Geochemical fingerprinting of tephra glass using major and trace element analyses and correlations of tephra layers between the three cores allowed the identification of 119 unique tephras, suggesting eruptions of magnitude (M) of 5.8–7.8. Age estimates for all the identified eruptions were obtained with the help of published and further refined age models for the studied cores, direct 40Ar/39Ar dating of four ash layers, and Bayesian age modeling. The glass compositions vary from low‐ to high‐K2O basaltic andesite to rhyolite and exhibit typical subduction‐related affinity. The majority of the tephras originated from Kamchatka, only a few tephras—from the neighboring Kuril and Aleutian arcs. The glass compositions revealed no temporal trends but made it possible to identify their source volcanic zones in Kamchatka and, in some cases, to determine their source eruptive centers. Our data indicates episodes of explosive activity recorded in the Detroit tephra sequence at ∼6,200, 5,600–5,000, 4,300–3,700 ka, and almost continuous activity since ∼3,000 ka. Within the latter episode, the most active intervals can be identified at 1,700–1,600, 1,150–1,050, and 600–50 ka. Geochemically fingerprinted and dated Detroit tephra sequence form a framework for dating and correlating diverse paleoenvironmental archives across the Northwest Pacific and for studies of geochemical evolution of the adjacent volcanic arcs. Plain Language Summary: Explosive volcanic eruptions produce defragmented material named tephra, which can be spread over large distances and form layers in sediments on ocean floor and continents. Long continuous tephra sequences preserved in marine sediments provide one of the best chronicles of the explosive eruptions, and allow detailed evaluation of their timing relative to climatic changes. We studied one of such natural records of explosive volcanism preserved in the sediments covering the Detroit Seamount in the Northwest Pacific. We identified 119 tephra layers, which have been buried in the sediments during the last 6.2 Ma and represent volcanic eruptions with ≥7 km3 tephra volume. We analyzed geochemical composition and determined age of each tephra. Most tephras were found to originate from volcanoes in Kamchatka, a few from the Kuril and Aleutian volcanoes. We found that the explosive activity recorded in the Detroit tephra sequence was not uniform over time. It peaked at ∼6,200, 5,600–5,000, 4,300–3,700, has continued since ∼3,000 thousand years ago until present. All tephra layers from our study can be used as unique isochrons for dating and correlating paleoenvironmental archives across the Northwest Pacific and for the reconstruction of the detailed volcanic record in the Earth history. Key Points: We report age and composition for 119 tephras from sediment cores representing ∼6.2 Ma record of explosive volcanism in the NW PacificThe tephras have subduction‐related origin and mostly originate from volcanic eruptions with magnitude (M) of 5.8–7.8 in KamchatkaThe data indicates episodes of explosive activity at ∼6,200, 5,600–5,000, 4,300–3,700 ka, and almost continuous activity since ∼3,000 ka [ABSTRACT FROM AUTHOR]

This paper summarizes previous studies of Palaeoloxodon naumanni, including stratigraphic distribution, chronology, morphological characteristics, taxonomy, habitat, and accompanying fauna. P. naumanni has been reported from over 300 sites on the Japanese Islands, ranging from 44° to 33° N latitude. Many of them have been dated by tephra stratigraphy, sequence stratigraphy, or 14C dating. Based on the age-dated specimens, P. naumanni is thought to have lived in Japan from 340,000 to 26,000 years ago. Skeletal morphology of P. naumanni is well known. In particular, the skull has been identified as male and female. And the examination of the skulls indicate that Palaeoloxodon is an independent genus within Elephantinae, and also P. naumanni as an independent species within Palaeoloxodon. Based on the vegetation data obtained from P. naumanni localities and the co-existed animal species with P. naumanni indicate that it has inhabited mixed forests with deciduous broad-leaved trees and conifers in the temperate zone. During the latter half of the Late Pleistocene, when the mammoth fauna migrated southwards to Japan, the deciduous broad-leaved forests that were widespread in Honshu were inhabited by the fauna accompanied by P. naumanni. These two faunas repeatedly shifted north and south in response to global climatic changes. [ABSTRACT FROM AUTHOR]

Understanding supra-regional climate variability such as the changes in the North Atlantic realm is important to identify the drivers of the climate system. In this study maar lake sediments from the Eifel (western Germany) were analysed with a multi-proxy approach and compared to central and western European speleothem growth phases. C org (chlorins) and the pollen assemblage were analysed from two sediment cores of the Hoher List infilled maar lake. To generate C org (chlorins) and pollen records covering the entire last 130,000 yr b2k (years before year 2000 CE), the data from this study were stacked with published data from other Eifel maar lake sediment cores (Sirocko et al., 2013, 2021, 2022). The sediment cores from Hoher List infilled maar lake were dated by marker tephra layers giving chronological anchor points and the precise dating of the sediment cores was performed by the tuning of the C org (chlorins) records to the NGRIP δ18O record (Rasmussen et al., 2014). The speleothems, whose growth phases are compared to the lake sediment proxy records, were compiled from the literature as well as speleothems from Dechencave (western Germany) dated by the 230Th/U-method in this study. The C org (chlorins) variability shows the bioproductivity in the maar lake, which is related to water temperature and corresponds to the Greenland Interstadials (GIs) in the NGRIP δ18O record indicates its dependence on supra-regional climate variations in the North Atlantic. The pollen record shows three periods of forest with temperate forest species, during the Eemian, early Marine Isotope Stage (MIS) 3, and the Holocene. Speleothem growth in four caves in central and western Europe (Dechencave, Spannagel Cave, Hölloch Cave, Villars Cave) is predominantly sensitive to cold periods with glaciers and/or permafrost conditions above the caves inhibiting speleothem growth. The forested phases and phases of high bioproductivity in the Eifel correspond well with phases of speleothem growth indicating three warm phases in central Europe during the last glacial cycle. [ABSTRACT FROM AUTHOR]

ABSTRACTThe Kamchatka Peninsula lies on the eastern active margin of Eurasia, adjacent to the Kuril-Kamchatka subduction zone. In this study, we provide a geomorphological map of the Central Kamchatka Depression – the largest sedimentary basin in Kamchatka and also in all the island arcs of the North Pacific. The depression extends along Kamchatka at latitudes ∼44–46° N for more than 400 km and is up to 100 km wide. The geomorphological map of the Central Kamchatka Depression is designed at a scale of 1:500,000 and contains ∼3000 mapped objects. Volcanic and tectonic landforms have been collected from published sources and generalised to the map scale. Glacial and fluvial landforms have been mapped using remote sensing data and field geomorphological surveys. Areas of ambiguous interpretation have been outlined. This map is the most detailed geomorphological map published for this region that may guide further geomorphological and paleogeographical investigations.

Abstract Alaska contains over 130 volcanoes and volcanic fields that have been active within the last 2 million years. Of these, roughly 90 have erupted during the Holocene, with many characterized by at least one large explosive eruption. These large tephra‐producing eruptions (LTPEs) generate orders of magnitude more erupted material than a “typical” arc explosive eruption and distribute ash thousands of kilometers from their source. Because LTPEs occur infrequently, and the proximal explosive deposit record in Alaska is generally limited to the Holocene, we require a method that links distal deposits to a source volcano where the correlative proximal deposits from that eruption are no longer preserved. We present a model that accurately and confidently identifies LTPE volcanic sources in the Alaska‐Aleutian arc using only in situ geochemistry. The model is a voting ensemble classifier comprised of six conceptually different machine learning algorithms trained on proximal tephra deposits that have had their source positively identified. We show that incompatible trace element ratios (e.g., Nb/U, Th/La, Rb/Sm) help produce a feature space that contains significantly more variance than one produced by major element concentrations, ultimately creating a model that can achieve high accuracy, precision, and recall on predicted volcanic sources, regardless of the perceived 2D data distribution (i.e., bimodal, uniform, normal) or composition (i.e., andesite, trachyte, rhyolite) of that source. Finally, we apply our model to unidentified distal marine tephra deposits in the region to better understand explosive volcanism in the Alaska‐Aleutian arc, specifically its pre‐Holocene spatiotemporal distribution.

The AMUSED (A MUltidisciplinary Study of past global climatE changes from continental and marine archives in the MeDiterranean region) project aims at improving knowledge of late Quaternary climate variability and its expressions in different geological settings of the Mediterranean region. In this framework, the Castiglione maar, in the Colli Albani Volcanic District, central Italy, was selected for acquiring a high-resolution and geochronologically well-constrained multi-proxy record by drilling the entire lacustrine succession. Electrical Resistivity Tomography (ERT) profiles were acquired across the central portion and the SW crater edge to depict the geometry of the sedimentary infilling and select the best drilling site. Two parallel cores (C1 and C2), 116 m- and 126.5 m-depth respectively, were recovered from the central sector of the Castiglione basin, where, according to ERT profiles, the sedimentary succession reaches the maximum thickness. The sedimentary infilling consists of fine-grained sediments: mainly fine sand, silt and clay, with minor gravel intervals and numerous tephra layers and volcaniclastic lenses. Specifically, more than 60 tephras were identified and used, alongside other lithostratigraphic features, to correlate the C1 and C2 cores and to assemble a composite section. The variability in magnetic susceptibility, led by glacial-interglacial cycles, and the geochemical fingerprinting of key tephra layers allowed to establish a preliminary chronological framework for the Castiglione succession which certainly spans the last 365 ka, with a mean sedimentation rate of 0.33 mm/yr. The relatively long time span of the Castiglione maar succession arises as a new potentially meaningful node of the network of Mediterranean records for better reconstructing the late Quaternary climate dynamics on a regional and extra-regional scale. [ABSTRACT FROM AUTHOR]

Holocene environmental changes in Patagonia were mostly shaped by unsteady ice-cover recession. Consequently, environmental reconstructions are largely based on discontinuous moraine chronologies from valley deposits. Here, we present a 3 m-long continuous sediment record recovered from Laguna Meseta (LME), a lake located on Meseta Chile Chico. Its altitude and location relative to the North Patagonian Icefield provide a unique opportunity to reconstruct the glacial history and the related environmental dynamics. Our radiocarbon chronology constrains sedimentation to the last ~10,000 years and provides a minimum age for postglacial ice-free lacustrine conditions due to a westward retreat of the ice cap. Lacustrine productivity reached its maximum at the start of sedimentation and decreased afterwards. Between 5,500 and 4,600 cal yr BP, a major shift towards allochthonous sediment accumulation occurred, caused by an abrupt increase in clastic deposition from basaltic lithologies of the Meseta Chile Chico. This episode correlates with the precipitation-driven mid-Holocene glacier advance of Patagonian glaciers and suggests that conditions were colder/wetter on the Meseta Chile Chico at that time. After 4,600 cal yr BP these conditions continued to supply LME with clastic sediments until a stepped decrease around 900 cal yr BP. Thereupon, lacustrine productivity distinctly increased and stabilized around 300 cal yr BP. Our findings indicate that environmental conditions on Meseta Chile Chico were mainly controlled by precipitation variability during regional oscillations of the Southern Hemisphere Westerly Winds over the last 10 ka. [ABSTRACT FROM AUTHOR]

Deep Springs Valley (DSV) is a hydrologically isolated valley between the White and Inyo mountains that is commonly excluded from regional paleohydrology and paleoclimatology. Previous studies showed that uplift of Deep Springs ridge (informal name) by the Deep Springs fault defeated streams crossing DSV and hydrologically isolated the valley sometime after eruption of the Pleistocene Bishop Tuff (0.772 Ma). Here, we present tephrochronology and clast counts that reaffirms interruption of the Pliocene--Pleistocene hydrology and formation of DSV during the Pleistocene. Paleontology and infrared stimulated luminescence (IRSL) dates indicate a freshwater lake inundated Deep Springs Valley from ca. 83-61 ka or during Late Pleistocene Marine Isotope Stages 5a (MIS 5a; ca. 82 ka peak) and 4 (MIS 4; ca. 71-57 ka). The age of pluvial Deep Springs Lake coincides with pluvial lakes in Owens Valley and Columbus Salt Marsh and documents greater effective precipitation in southwestern North America during MIS 5a and MIS 4. In addition, we hypothesize that Deep Springs Lake was a balanced-fill lake that overflowed into Eureka Valley via the Soldier Pass wind gap during MIS 5a and MIS 4. DSV hydrology has implications for dispersal and endemism of the Deep Springs black toad (Anaxyrus exsul). [ABSTRACT FROM AUTHOR]

Tephra preserved in sediments form useful isochronous marker layers, linking disparate geological, palaeoenvironmental and archaeological records. The application of tephrochronology is greatly enhanced through the detection of macroscopically invisible tephra (cryptotephra). Here, we identify two discrete cryptotephra in Samoan lake sediments, the first identification of cryptotephra in the region outside of New Zealand. Geochemical data suggest one ash layer is from a local Samoan source, providing the first data on an eruption of this age, adding to knowledge of the local volcanic record. The second has a distinctive rhyolitic glass composition, which matches either that of Raoul Island in the Kermadec Arc (1800 km south of Samoa), or two currently submarine volcanoes in the Tongan Arc, 'Volcano F' and Lateiki/Metis Shoal (550 and 700 km south of Samoa, respectively). In all possible source cases, this points to a regionally significant eruption of a Kermadec–Tongan volcano at ca. 10 000 a bp. The study marks the first step in the establishment of a South Pacific tephra framework that can be used to answer questions about the synchronicity of changes in hydroclimate, vegetation and early Polynesian migration patterns, as well as providing more information on the volcanic history of Pacific island volcanoes. [ABSTRACT FROM AUTHOR]

Historical perspective helps ecologists and conservationists to better understand modern processes and potential future changes, but collecting long-term ecological data with fine spatiotemporal resolution is challenging. The aim of this study was to reconstruct mire vegetation about 1100 years ago by applying local components that represent the positions of local plants and the mire margin. From the plot-based comparison between modern pollen and vegetation, Sanguisorba, other Rosaceae, Ericaceae and Sphagnum were considered to be local components that signify the position of source plants within about 1 m. Ilex, Acer and Lysichiton were estimated to have attributes of both local and extra-local components and to indicate the mire margin with a few metres’ resolution. These results allowed reconstruction of the millennium-scale changes in the mire’s areal extent and local vegetation. The site was a wetter Sphagnum mire in 915 CE and has changed to a drier one, with Geum pentapetalum now more common. The maximum extent of the mire has retreated about 5 m, although the margin around the depressed northern end has slightly expanded. Nevertheless, the mire has maintained a peatland of similar size during the last millennium. Plot-based pollen and vegetation analysis is useful and can assist ecologists and conservationists to choose the proper conservation procedures.

The tectonic setting of the southernmost part of the eastern margin of Laurentia during the Blountian tectophase (~472–452 Ma) of the Ordovician Taconic Orogeny remains unresolved. Tephras produced by explosive volcanism during this early phase of the orogeny are now K-bentonites, and in many locations, they are interbedded with mature to supermature quartz arenites. We conducted U-Pb analyses of detrital zircons from the sandstones, and of zoned magmatic zircons from the K-bentonites, to constrain the tectonostratigraphic setting with more precision. We also used geochemical fingerprinting of apatite phenocrysts to correlate the K-bentonites in these sandstones along the tectonic front, and we then integrated these results with a depositional systems study of the quartz arenites to further constrain and test competing models of the regional tectonomagmatic setting during that time. The general dearth of detrital zircons that have ages contemporaneous with the volcanic activity, coupled with the predominantly Precambrian ages of the zircons in these Lower Paleozoic quartz arenites that otherwise lack volcaniclastic components—such as detrital VRFs or a muddy matrix derived from an eroding volcanic arc—suggests that magmatic zircons from the tephra layers entered the depositional system only occasionally, and that the volcanic centers were separated geographically from where these quartzose sands were being deposited. Our findings support a tectonostratigraphic and tectonomagmatic model analogous to a combination of select modern settings in the western Pacific and Indonesia, specifically (1) New Guinea, where mature quartz arenites occur in the Cenozoic foreland succession, and (2) Sumatra, where the enormous Toba caldera formed in association with subduction beneath the Cretaceous-aged continental crust of Sumatra. [ABSTRACT FROM AUTHOR]

The environmental variability of Northern Chilean Patagonia during the last millennia is evaluated using a multi-proxy analysis of sediment cores from Lake Esponja (45°S 72°W) to decipher if the sediment deposition is controlled by volcanic eruptions, landslides induced by earthquake or heavy rainfall. The lake is located in a glacio-tectonic valley in Patagonia. The organic-rich clayey silt sediment with low biogenic silica content was analysed for grain size, magnetic susceptibility, organic matter, biogenic silica content and diatom assemblages, mineralogy (X-ray diffraction), organic (IRMS C and N analyses) and inorganic (XRF core-scanner) geochemistry and glass shard major composition (Microprobe, SEM). The combination of 210Pb, 137Cs, 14C and tephrochronology indicates an averaged accumulation rate of 0.4 mm/year, leading to a record of ~3.5 kyr within 154 cm. The sedimentary geochemistry records changes in volcanic supplies, diatom productivity and detrital inputs. The sediments were interrupted by millimetric to centimetric layers corresponding to tephra deposition related to explosive eruptions of nearby volcanoes Macá, Melimoyu and Hudson. Concerning the diatoms, the dominant planktonic species (80–150 cm) are replaced by benthic species in a transition interval (55–80 cm) and then by Surirella spp. in the upper core. This last genus indicates a closure of the basin ~2 ka ago, probably related to an uplift linked to a rejuvenation of the Mañihuales fault. This local change could reflect regional tectonic instability. Indeed, a partial earthquake rupture occurred around ~AD100 along the southern part of the Valdivia segment, recorded as a mass transport deposit in Aysén fjord sedimentation. The fine detrital input varies over time with more variable Si/Al values in the lower part of the LEs14 core than in the upper 80 cm. The higher values may reflect wetter conditions, leading to an higher lake level and more turbid conditions in agreement with changes in diatom assemblages. [ABSTRACT FROM AUTHOR]

The analysis of tephra layers in maar lake sediments of the Eifel shows 14 well-visible tephra during the last glacial cycle from the Holocene to the Eemian (0–130,000 yr b2k). These tephra were analyzed for their petrographic composition, which allows us to connect several tephra to eruption sites. All tephra were dated by application of the ELSA-20 chronology, developed using the late Pleistocene infilled maar lake of Auel and the Holocene lake Holzmaar (0–60,000 yr b2k). We extend the ELSA-20 chronology with this paper for the millennia of 60,000–130,000 yr b2k (ELSA-23 chronology), which is based on the infilled maar lake records from Dehner, Hoher List, and Jungferweiher. The evaluation of the tephra from the entire last glacial cycle shows that all 14 tephra were close to interstadial warming of the North Atlantic sea surface temperatures. In particular, phreatomagmatic maar eruptions were systematically associated with Heinrich events or C-events. These events represent times of warming of the Southern Hemisphere, global sea level rise, and CO2 increase, which predate the abrupt interstadial warming events of the Northern Hemisphere. This synchroneity indicates a physical relationship between endogenic and exogenic processes. Changes in the lithospheric stress field in response to changes in continental ice loads have already been suggested as a potential candidate to explain the exogenic forcing of endogenic processes. The chronology of volcanic activity in the Eifel demonstrates that intraplate mantle plumes are also affected by the exogenic forcing of endogenic processes.

Thirty‐two tephra layers were identified in the time‐interval 313–366 ka (Marine Isotope Stages 9–10) of the Quaternary lacustrine succession of the Fucino Basin, central Italy. Twenty‐seven of these tephra layers yielded suitable geochemical material to explore their volcanic origins. Investigations also included the acquisition of geochemical data of some relevant, chronologically compatible proximal units from Italian volcanoes. The record contains tephra from some well‐known eruptions and eruptive sequences of Roman and Roccamonfina volcanoes, such as the Magliano Romano Plinian Fall, the Orvieto–Bagnoregio Ignimbrite, the Lower White Trachytic Tuff and the Brown Leucitic Tuff. In addition, the record documents eruptions currently undescribed in proximal (i.e. near‐vent) sections, suggesting a more complex history of the major eruptions of the Colli Albani, Sabatini, Vulsini and Roccamonfina volcanoes between 313 and 366 ka. Six of the investigated tephra layers were directly dated by single‐crystal‐fusion 40Ar/39Ar dating, providing the basis for a Bayesian age–depth model and a reassessment of the chronologies for both already known and dated eruptive units and for so far undated eruptions. The results provide a significant contribution for improving knowledge on the peri‐Tyrrhenian explosive activity as well as for extending the Mediterranean tephrostratigraphical framework, which was previously based on limited proximal and distal archives for that time interval. [ABSTRACT FROM AUTHOR]

Hydrothermal explosions are significant potential hazards in Yellowstone National Park, Wyoming, USA. The northern Yellowstone Lake area hosts the three largest hydrothermal explosion craters known on Earth empowered by the highest heat flow values in Yellowstone and active seismicity and deformation. Geological and geochemical studies of eighteen sublacustrine cores provide the first detailed synthesis of the age, sedimentary facies, and origin of multiple hydrothermal explosion deposits. New tephrochronology and radiocarbon results provide a four-dimensional view of recent geologic activity since recession at ca. 15-14.5 ka of the >1-km-thick Pinedale ice sheet. The sedimentary record in Yellowstone Lake contains multiple hydrothermal explosion deposits ranging in age from ca. 13 ka to ~1860 CE. Hydrothermal explosions require a sudden drop in pressure resulting in rapid expansion of high-temperature fluids causing fragmentation, ejection, and crater formation; explosions may be initiated by seismicity, faulting, deformation, or rapid lake-level changes. Fallout and transport of ejecta produces distinct facies of subaqueous hydrothermal explosion deposits. Yellowstone hydrothermal systems are characterized by alkaline-Cl and/or vapor-dominated fluids that, respectively, produce alteration dominated by silica-smectite-chlorite or by kaolinite. Alkaline-Cl liquids flash to steam during hydrothermal explosions, producing much more energetic events than simple vapor expansion in vapor-dominated systems. Two enormous explosion events in Yellowstone Lake were triggered quite differently: Elliott's Crater explosion resulted from a major seismic event (8 ka) that ruptured an impervious hydrothermal dome, whereas the Mary Bay explosion (13 ka) was triggered by a sudden drop in lake level stimulated by a seismic event, tsunami, and outlet channel erosion. [ABSTRACT FROM AUTHOR]

Zircon crystals from ash layers intercalated with fossil-rich sediment from Natural Trap Cave (NTC) in Wyoming (USA) were investigated to refine the chronostratigraphy of this unique late-Quaternary megafaunal assemblage. Glass compositions of individual glass spicules and glass adherent to zircon along with a characteristic low-δ18O signature of zircon (on average + 2.4‰ relative to Vienna standard mean ocean water) indicate tephra provenance from post-Lava Creek Tuff activity of Yellowstone. Yellowstone glass composition was hence used to anchor the 230Th/238U zircon isochron and to compute model crystallization ages, which translate into maximum depositional ages. For the lowermost visible tephra layer in new excavations in NTC strata, an upper age limit of 138 ± 9 ka (1σ age uncertainty) was thus obtained. A younger tephra with a230Th/238U zircon date of 111 ± 8 ka is tentatively correlated with Tuff of Cold Mountain Creek from the Central Plateau Member of Yellowstone, suggesting a minor lag time between zircon crystallization and eruption. The NTC tephra record thus has high potential for refining the explosive volcanic history and tephra distribution patterns of Yellowstone during the late Pleistocene. [ABSTRACT FROM AUTHOR]

Natural Trap Cave, located in the Big Horn Mountains of north-central Wyoming, has a history of trapping and preserving a range of North American fauna that plummeted into the deep vertical entrance. These animal remains were buried and preserved within sediments of the main chamber and, in turn, have helped elucidate the procession of faunal dynamics during the latest glacial cycle. The cave location, south of the Laurentide and Cordilleran Ice Sheets, and proximal to Yellowstone, is at an ideal geographical juncture to provide insights to ecological changes in North America. The sediments that the animals are buried in inform us about transport and deposition both inside and outside of the cave that relate to catchment dynamics. We report on a series of optically stimulated luminescence (OSL) ages derived from samples obtained within the cave during excavation work in 2014 and in 2018. We also examine chronology produced by argon, tephrochronology, fission track, and luminescence techniques that have been used for understanding the infilling of the cave. The cave sediment ages and in situ measured gamma spectroscopy as measured in this study helped resolve an improved chronological age model when combined with previous data. The suite of OSL ages is interpreted through the stratigraphic relationships (and vertebrates contained within) which requires the use of an adequate age model; we use either the central age model or minimum age model where appropriate and with justification. Lowest sediments are dated to ∼150 ka with a hiatus at ∼130 to 52 ka. Above this, sediment deposition and entrainment of paleontological materials are representative of Pleistocene and early Holocene times, between 37 ± 6 ka and 7.6 ± 0.5 ka. The stratigraphic architecture suggests that deposition of materials into the cave is episodic and rapid, followed by quiescent periods where hydrologic scour, heavy overland flow, or possibly a cryo-hydrologic process may have altered unit relationships. Thus, the complementary geochronometers and the characteristics of quartz versus feldspar luminescence signals improve temporal interpretations of these complex deposits. This adapted understanding of mixing also sets the stage for future work with the aim to improve our understanding of ages and sources for ash units within these cave deposits. The three ash units recognized in the cave may represent an in-situ reworking of the same ash or may be representative of previously undocumented eruptions from the Yellowstone Caldera. [ABSTRACT FROM AUTHOR]

Mineral dust concentrations are coupled to climate over glacial-interglacial cycles with increased dust deposition occurring during major cold phases over the last ~100 ka. Holocene records suggest considerable spatial and temporal variability in the magnitude, frequency and timing of dust peaks that reflects regional or local drivers of dust emissions and transport. Here, we present stratigraphical, geochemical and isotopic evidence for dust deposition from two high-resolution peat sequences 200 km apart in northern Scotland spanning the last c. 8200 years. εNd isotope data suggest the dominant minerogenic dust source switches between a low latitude (likely Saharan) and a high latitude, Icelandic source. Marked peaks in increased minerogenic dust deposition at: c. 5.4–5.1, 4.0–3.9, 2.8–2.6, 1.0 and 0.3 ka BP occur against a backdrop of low dust deposition during the mid-Holocene (c. 5.0–4.0 ka BP) and increased background levels of dust during the neoglacial period (<4.0 ka BP). These dust peaks coincide with periods of glacial advance in Iceland and heightened storminess in the North Atlantic. Isotope data for additional dust peaks at c. 1.0 and 0.7 ka BP and the last ~50 years suggest these reflect increased dust from the Sahara associated with aridity and land-use change in North Africa during the Late-Holocene, and modern anthropogenic sources. This work highlights the complexity of Holocene records of dust deposition in the North Atlantic and emphasises the role of dynamic sub-Polar glaciers and their meltwater systems as a significant dust source. [ABSTRACT FROM AUTHOR]

• Ages of uplifted marine terraces in western Japan are determined. • Tephrochronology based age determinations confirm the age of TCN derived terraces. • Combined multi-nuclides and depth profile cosmogenic radiometric dating is effective. The southern coasts of Shikoku Island and the Kii Peninsula are located along the Nankai Trough where the Philippine Sea Plate is subducting under the Eurasian plate in Japan. Relatively well-preserved marine terraces along the coast, with elevations ranging between ca. 50 and 100 m, are suitable counterparts to reconstruct the uplift history of the southwestern coast of Japan due to the unique tectonic setting. In this study, we attempt to determine the age of the marine terraces by employing in-situ terrestrial cosmogenic radionuclides (TCN), 10Be and 26Al. TCN depth profiles provide information on the timing of terrace formation. General agreement between our TCN chronology and the existing tephrochronology show that the TCN method can be applicable to a mid-latitude coastal setting where erosion must also be considered. Thus, measuring TCN on uplifted terraces around Japan can be a promising technique for clarifying uplift rates and the seismic history of the region. [ABSTRACT FROM AUTHOR]

We present the findings of a detailed non-visible (cryptotephra) tephra investigation of the Lake Suigetsu (Japan) sedimentary sequence spanning ∼120 to 50 ka. Thirty-nine new cryptotephra and two visible tephra horizons are identified during this interval interspersed between visible tephra layers associated with large-magnitude eruptions and regional event markers (e.g., Aso-4, K-Tz, Ata). The newly identified volcanic deposits are geochemically analysed using major (EMP) and trace (LA-ICP-MS) element glass analyses, and the chemical fingerprints are used to trace these deposits to subduction related volcanoes located along the three main Japanese islands (Kyushu, Honshu and Hokkaido), as well as nearby intraplate volcanoes. Our findings provide geochemical, chronological and ash-fall constraints on the activity at multiple volcanic centres; in particular, the Kirishima volcanic complex in the southern volcanic region of Kyushu. Furthermore, the Lake Suigetsu cryptotephra record reveals distal ash-fall from two notable large magnitude (≥M6.0) eruptions, the Plinian Sambe Kisuki (SK) eruption and the caldera-forming Toya eruption, both of which are important widespread tephrostratigraphic markers suitable for linking regional terrestrial and marine sequences. Using the Lake Suigetsu age-depth model, they are dated to 100.4 ± 3.1 ka (±1σ) and 108.1 ± 3.9 ka (±1σ), respectively. Finally, our investigation reveals numerous eruption deposits which have not yet been identified in near-vent sequences, indicating eruption under-recording. This research re-affirms Lake Suigetsu as the single most comprehensive ash-fall record of East Asian explosive volcanism over the past 150 kyr, and contributes significantly to our understanding of the timing and ash dispersals of pre-historic eruptions. • Forty-one crypto-/tephras identified Lake Suigetsu archive spanning ∼120–50 ka. • Tephras are mostly from volcanoes in Kyushu, with a few from Hokkaido and intraplate sources. • Frequent explosive activity from Kirishima volcanic complex over a 19 kyr interval. • Provide ages for the widespread SK (100.4 ± 3.1 ka) and Toya (108.1 ± 3.9 ka). [ABSTRACT FROM AUTHOR]

In the highlands of Papua New Guinea (PNG), tephras are key chronostratigraphic markers for archaeological and palaeoenvironmental studies. Here, mid-Late-Holocene tephras are geochemically fingerprinted and correlated across seventeen sites in PNG. This enables the first regional scale assessment of the distribution of these tephras, with implications for both assessing eruption magnitude and interpreting site stratigraphy. In the past, stratigraphic relationships have been key to much of the tephra identification done in PNG. Fingerprinting presented here shows that tephras may be either locally or regionally absent, as a result of poor preservation or regional distribution patterns, reinforcing the need for geochemical identification. Fingerprinting has also allowed tephras to be correlated with their source volcano. In a number of cases (e.g. Kuning and Mun tephras), this has enabled significant refinement of tephra ages, as source eruptions have been accurately dated using charcoal in proximal pyroclastic sequences. This has significant implications for regional archaeological and palaeoenvironmental studies. Of the six regionally widespread tephras emplaced over the last 4–5 ka in PNG, four are sourced from either Long Island or Karkar volcanoes in the western Bismarck Arc, while two are the result of eruptions from Dakataua and Witori volcanoes in New Britain. Discovery on the PNG mainland of tephras sourced from New Britain significantly increases the known distribution of products from these eruptions, suggesting current evaluations of eruption magnitude may be underestimates. [ABSTRACT FROM AUTHOR]

Cryptotephras recorded in sediments are valuable isochrons with which to reconstruct volcanic eruptive history and synchronize environmental changes across large regions. Here we identify four cryptotephras from Jeju Island, Republic of Korea, that constitute tie-points linking palaeoenvironmental records of tropical to mid-latitude east Asia. A cryptotephra of unknown source with trachytic glass compositions at around 2700 cal a BP (named M263a) can be correlated with the HGY263 recorded in the Huguangyan Maar lake in southern China, and SG14–0433 recorded in Suigetsu lake in central Japan. Another population of glass shards with basaltic andesitic to trachybasaltic composition (named M263b) represents the first cryptotephra record of a Jeju eruption. A rhyolitic cryptotephra at ∼7384 cal a BP (H53) can be correlated with the ∼7.3 ka Kikai-Akahoya eruption (specifically, the K-Ah tephra) from Kikai caldera, southern Kyushu, Japan. The cryptotephra coincides with a marked change in aquatic algae communities in Jeju sediments, possibly signifying a climate response to the eruption. Additionally, cryptotephra layers at ∼6948 cal a BP (H22) in the Hanon Maar Lake and ∼ 1030 cal a BP (M125) in Mulyoungari wetland exhibit similar glass compositions to those of the K-Ah tephra, which suggests they are the product of unknown eruptions from Kikai or a neighboring volcano. Given the widespread distributions of K-Ah and M263a tephra across east Asia, Jeju sediments can be precisely synchronized with those high-resolution sediments from southern China and Japan, providing two Holocene marker horizons for palaeoenvironmental comparisons across east Asia. Our work shows great promise for the improved chronological constraints and inter-site linkages for palaeoenvironmental sequences in the region through the application of tephrochronology. • East Asian Holocene sedimentary archives can be precisely synchronized through geochemically-characterized cryptotephra marker horizons. • Cryptotephras from the ∼7.3 ka Kikai caldera eruption, and possibly other Kikai eruptions, and local Jeju eruptions were recognized from Jeju sediments for the first time. • The largest Holocene Kikai-Akahoya eruption may have produced a regional, short-term climate impact. [ABSTRACT FROM AUTHOR]

Integrating proximal and medial-distal tephra records from continuous sedimentary archives has recently proven to be crucial for obtaining more complete and highly resolved stratigraphic and chronological histories of explosive activity, allowing a detailed and accurate assessment of volcanic hazards. The sedimentary succession from the Castiglione maar, about 20 km east of Rome, hosts a long and continuous lacustrine record extending back to ca. 365 ka, including a number of tephra layers derived from the explosive activity of peri-Tyrrhenian volcanic centres. An integrated tephrochronological investigation, which combines stratigraphic, textural, mineralogical, geochemical and 40Ar/39Ar geochronological analyses, was conducted on six tephra layers occurred between 11 and 15 m-depth of the Castiglione composite section. This section records the history of the most recent explosive activity of the Colli Albani volcano and relates to the Albano maar. Results reveal that the Albano maar volcanic history actually comprises six explosive events that are younger than previously thought and occurred in a narrower time interval. Specifically, 40Ar/39Ar ages determined on four of the six tephra, along with the modelled ages for the remaining two, indicate that the eruptive activity of the last sub-cycle of the Albano maar lasted 3.4 +0.4/-0.6 ka, and occurred between 37.71 ± 0.34 ka (40Ar/39Ar age of the first eruption) and 34.34 +0.25/-0.45 ka (modelled age of the last eruption). Results refine the history of the most recent explosive activity at Colli Albani volcano and underscore the importance of studying tephra preserved in medial-distal continuous sedimentary archives for a comprehensive reconstruction of the eruptive history. Based on the data collected, the previously unrecognised explosive eruptions were likely of medium magnitude but sufficiently large to produce highly fragmented and widely dispersed ash. We argue that these new findings should be considered for an updated long-term hazard assessment of the Colli Albani volcanic area. Results, and especially the new high-precision ages, also allow to improve the tephrochronological framework in the dispersal area of the Albano tephra, including the iconic paleoclimatic archives of Monticchio and Fucino. • Integrated tephrochronology utilized to understand the volcanic history of Albano maar, Italy. • High-resolution tephra record from the Castiglione maar, provide detailed insights into the volcanic activity. • Six tephra from the last eruptive sub-cycle of the Albano maar enhance our understanding of its volcanic history. • New data updates the chronology of eruptions from the Albano maar, enhancing the accuracy of the volcanic timeline. • High-resolution stratigraphic and chronological studies are vital for accurate hazard assessment and understanding volcanic activity. [ABSTRACT FROM AUTHOR]

Raised shorelines and associated lacustrine sediments in the central Estrecho de Magallanes (Strait of Magellan) have been interpreted as products of cordilleran glaciers impounding a large proglacial lake and preventing drainage to the South Pacific and Southern Ocean during the Late glacial between c. 15.0 and 12.0 cal ka BP. However, a growing body of glacial geological evidence points towards an earlier retreat of the Magellan cordilleran ice dome, insufficient to dam lakes at that time. We critically re-evaluate the extant evidence for the c. 15.0–12.0 cal ka BP lake, here named 'Lago Kawésqar', and provide further sedimentological and chronological evidence for its existence. We also provide new cosmogenic surface nuclide dating of erratic and bedrock samples collected from extensive field campaigns that confirm the rapid and widespread retreat of the Magellan ice fields to the inner fjords of the Fuegian archipelago by c. 16.0 ka. To resolve the apparent paradox between these two lines of evidence we propose that glacial isostatic adjustment led to a topographic barrier to lake drainage rather than an ice dam. We use Glacial Isostatic Adjustment modelling to demonstrate that rapid isostatic recovery following the early deglaciation after c. 17.0 cal ka BP likely led to elevation of the present shallow south-western coastal margin of the Fuegian archipelago. Final drainage of Lago Kawésqar was probably caused by neotectonic subsidence of the same margin along the boundary of the South American – Scotia tectonic plates at c. 12.0 cal ka BP. • Evidence for a large Late glacial lake in the Strait of Magellan is confirmed. • New ages for deglaciation of the Magellan ice dome after the LGM are presented. • An alternative theory for the damming of the Late glacial Magellan lake is discussed. • Glacial isostatic adjustment modelling supports bedrock uplift damming the lake. • A neotectonic event likely led to final drainage of the Magellan lake. [ABSTRACT FROM AUTHOR]

The Kamchatka Peninsula lies on the eastern active margin of Eurasia, adjacent to the KurilKamchatka subduction zone. In this study, we provide a geomorphological map of the Central Kamchatka Depression – the largest sedimentary basin in Kamchatka and also in all the island arcs of the North Pacific. The depression extends along Kamchatka at latitudes 44–46° N for more than 400 km and is up to 100 km wide. The geomorphological map of the Central Kamchatka Depression is designed at a scale of 1:500,000 and contains ∼3000 mapped objects. Volcanic and tectonic landforms have been collected from published sources and generalised to the map scale. Glacial and fluvial landforms have been mapped using remote sensing data and field geomorphological surveys. Areas of ambiguous interpretation have been outlined. This map is the most detailed geomorphological map published for this region that may guide further geomorphological and paleogeographical investigations. [ABSTRACT FROM AUTHOR]

Palaeomagnetic records from three cores of lake sediment have been merged, producing a new Holocene geomagnetic secular variation record for northern New Zealand. The cores are from Lake Pupuke, a maar lake in Auckland Volcanic Field (AVF). They contain tephra from Rangitoto Volcano (530 ± 10 yr BP), Taupō (1718 ± 10 yr BP), Tūhua/Mayor Island (7637 ± 100 yr BP) and Rotomā tephra from Ōkataina Volcanic Centre (9423 ± 120 yr BP). These tephra dates are supplemented by selected radiocarbon age estimates. The cores were correlated using tephra and fine-scale variations in magnetic susceptibility. The natural remanent magnetisation is strong, stable and carried by fine-grained titanomagnetite from AVF's basaltic volcanoes. The resulting palaeosecular variation (PSV) record spans from 10,000 to 1500 yr BP. It shows well-defined, millennial-scale swings in direction between 10,000 and 8000 yr BP and between 4000 and 1500 yr BP, while between 8000 and 4000 yr BP variations are of higher frequency and lower amplitude and centre on the geocentric axial dipole field direction. This is in excellent agreement with published PSV records from Mavora Lakes, 1000 km further south, indicating the regional nature of PSV – resulting from broad-scale changes in the circulation of conducting iron-rich fluid of Earth's outer core. [ABSTRACT FROM AUTHOR]

Terrestrial archives from the Mediterranean have been crucial to expanding our understanding of past environmental variability on a range of timescales. Dating Quaternary sequences in the Mediterranean is, however, often challenging, and age models often have large chronological uncertainties. Tephra deposits can provide crucial age control for detailed environmental reconstructions on sub‐centennial timescales. Here, tephra analysis is undertaken for the first time on a sediment core (I‐08) from Lake Ioannina, northwest Greece, for the interval spanning 46–4 ka bp. Detailed visible and 'crypto‐' tephra analysis identifies deposits associated with explosive volcanism at Italian volcanic sources, including Campi Flegrei, Pantelleria, and the Aeolian Islands. We identify two visible tephra layers, the Campanian Ignimbrite (CI/Y‐5; ca. 39.8 ka bp) and Pantelleria Green Tuff (PGT/Y‐6; ca. 45.7 ka), as well as the Holocene Vallone del Gabellotto cryptotephra marker (VG/E‐1; ca. 8.3 ka bp). Evidence for repeated remobilisation and redeposition of CI tephra material is outlined, and the potential mechanisms and effects of sediment reworking in lake environments are examined. Bayesian modelling, which incorporates the new tephra ages with earlier radiocarbon dates, extends the I‐08 core chronology back to ca. 46 ka bp, facilitating direct correlation of the Ioannina sequence to others in the Mediterranean region. [ABSTRACT FROM AUTHOR]

We present new lithostratigraphic, pollen‐stratigraphic and tephrochronological data obtained from a sediment sequence in a small lake basin in Glen Builg, eastern Cairngorms, with mapping of the surrounding glacial geomorphological features. The collective evidence indicates that basin organic sediment accumulation started during the Windermere Interstadial at ~14.3 ka. The new results reaffirm the conclusions of Clapperton et al. (1975), that any occupation of the eastern Cairngorms by Loch Lomond ('Younger Dryas') Stadial glacier ice was spatially restricted. The record also suggests that harsh climatic conditions prevailed throughout the Windermere Interstadial, probably due to the relatively high altitude of the site (~460 m) and its proximity to major Cairngorm peaks. Our new, more comprehensive study provides a robust chronology, and reveals several palaeoenvironmental signals congruent with other recently reported Scottish Highlands records. Key similarities with regional records are: (i) a short climatic reversal corresponding to GI‐1d in the Greenland stratotype sequence; (ii) a two‐phased Loch Lomond Stadial, with a transition around the Vedde Ash, dating to ~12.1 ka; and (iii) a delayed response to Early Holocene climatic warming of ~250 years, before soils were sufficiently stabilised to permit shrub vegetation establishment. [ABSTRACT FROM AUTHOR]