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The article highlights the difficulties connected with getting secure fixed-points for sea-level curve construction and emphasises the care that should be taken with data interpretation. As such, it is a welcome contribution to this important topic. On the other hand, the paper has, in my opinion, several weaknesses. It not only disregards a large body of reliable and highly relevant information on sea-level changes available from investigations carried out using a variety of methodologies, but also makes assumptions that seem to be based, to varying degrees, on misconceptions and misunderstandings. Many of these misunderstandings might have been avoided had the discussions, that are referred to in the Acknowledgements, actually taken place. I wish to take this opportunity to set the record straight by stating that no such discussions took place. [ABSTRACT FROM AUTHOR]

Deserts and sandylands that are located in the semi-arid and arid regions in the middle latitudes of the Northern Hemisphere are usually regarded as environmentally sensitive change belts which respond to global climatic change. In northern China, activation or immobilization of sand dunes is mainly influenced by humid and dry variation and is related to stronger or weaker Asian monsoons. In this paper, the history of Holocene millennial-scale climatic and environmental change is reconstructed by the systematic analysis of the geochemical element contents and parameters, along with the OSL and C chronologies, from the different lithologies of the palaeosol-aeolian sand sequence in the south-eastern Mu Us Desert, northern China. Our results indicate that the region was dominated by a dry climate with intensive aeolian activity before 7.2 ka BP, and there was an optimal humid climate and fixed desert in 7.2-4.6 ka. Afterwards, the dune fields became mobile again as the effective humidity declined. Additionally, six dry events were discovered with times of ~7.2, 7.0-6.8, 6.6-5.7, 4.6-4.1, 3.7-3.5, and 3.3-2.5 ka, which were not only coincident with the intervals of millennial-scale weaker Asian summer monsoons, but also accordant with the cold events evidenced in the ice cores and deep-sea deposits of the high latitudes in the Northern Hemisphere. In general, the Holocene climatic and environmental changes had the characteristics of the 'monsoonal mode' and 'abrupt millennial-scale oscillation' in the Mu Us Desert. [ABSTRACT FROM AUTHOR]

Changes in convective activity and hydroclimate over Northeastern Kalimantan are key features to understand glacial to interglacial climate evolution in the center of the West Pacific Warm Pool during the Late Pleistocene to Holocene. We use high-resolution X-ray fluorescence (XRF) scanner-derived elemental ratios in sediment Core SO217-18522 (1º 24.106' N, 119º 4.701'E, 975 m water depth) recovered from the northern Makassar Strait to reconstruct changes in precipitation-related weathering and erosion over Northeastern Kalimantan over the last 50 kyr. Enhanced seasonality of rainfall and an extended dry season during Heinrich Stadials (HS4 to HS1) and the Younger Dryas (YD) suggest weakening of the tropical convection associated with a southward shift of the tropical rain belt and the annual mean position of the Intertropical Tropical Convection Zone. Increasing sediment discharge and intensification of convective activity occurred during the early to mid-Holocene during an interval of high Northern Hemisphere insolation, elevated atmospheric pCO2 levels and global warming. Our reconstructions in comparison with regional terrestrial and marine records highlight the high spatial variability of Kalimantan hydroclimate on millennial to glacial-interglacial timescales. [ABSTRACT FROM AUTHOR]

Geophysical and geochemical methods were applied to detect the subsurface setting of an Upper Pleistocene-Holocene fluvial incised-valley where a travertine body intercalates between alluvial deposits of the Tiber river (central Italy), at Prima Porta (close to Rome). This study allowed us to provide more information regarding the local stratigraphic architecture and structural features, as a reference analogue to similar settings: i.e., hard (stiff) lithic travertines buried below fine and loose alluvial plain covers. Two Electrical Resistivity Tomography (ERT) profiles, interpreted and calibrated using previously collected litho-stratigraphic data from a borehole, identified a massive body, with a relatively high resistivity that correlates with the travertine deposit of Prima Porta. In addition to ERT, ambient noise measurements, processed with the HVSR technique and 2D array, and seismic refraction tomography were carried out; HVSR data were highly consistent with ERT results and allowed to discriminate between the travertine body and the silty-sand channels and overbank deposits, which were attributed to the Tiber river's evolution during Upper Pleistocene-Holocene. Finally, the presence of cracks/fractures could be inferred, as suggested by slight polarisation effects recorded in the HVSR results and soil-gas anomalies. [ABSTRACT FROM AUTHOR]

The Early Holocene (12–8.2 cal ka) deglaciation and pulsed warming was associated in Iceland with two major generations of jökulhlaups around the Vatna ice-cap (Vatnajökull), at ca 11.4–11.2 cal ka and ca 10.4–9.9 cal ka, and major tephra emissions from the Grímsvötn and Bárðarbunga subglacial volcanoes. The earliest flood events were recorded inland during the Middle Younger Dryas and their deposits were overlain by the Early Preboreal Vedde Ash (11.8 cal ka). The first Holocene flood events (ca 11.4–11.2 cal ka) are issued from a glacial advance. The second, and major, set of floods was partly driven by the Erdalen cold events and advances (10.1–9.7 10Be ka) initially issued from the Bárðarbunga (10.4, 10.1–9.9 ka) and Grímsvötn volcanoes (Saksunarvatn tephra complex, ca. 10.2–9.9 cal ka). These floods were also fed by the residual glacio-isostatic depressions below the Vatnajökull that enabled the storage of meltwaters in large subglacial lakes or aquifers until ca. 9.3 cal ka. This storage was enhanced by ice-damming and permafrost, especially during the twinned Erdalen events. Due to the glacio-isostatic rebound, the general slope was nearly flat, and the valley was partly filled with sediments until ca 10.8 cal ka. Temporary lacustrine deposits in this valley resulted from the very broad splay of waters as for the ca 11.2 cal ka and ca 10.1–9.9 cal ka flood, due to regional permafrost. These floods had a potential duration of several months as they were mostly fed by climate-driven meltwater. The maximal volume evacuated by these events did not greatly exceed 1 × 106 m3 s−1 from the flood-affected transverse profile of the valleys that remain partly filled with sediments. [ABSTRACT FROM AUTHOR]

Our research is aimed at estimating the vertical deformation affecting late Quaternary units accumulated into the foreland basin of the Northern Apennines chain. Beneath the study alluvial plain, compressive fault-fold structures are seismically active. We reconstructed the stratigraphic architecture and the depositional evolution of the alluvial deposits, which accumulated in the first 40 m of subsurface, through the last 45,000 years, from before the Last Glacial Maximum to the present. A 58 km-long stratigraphic profile was correlated from the foothill belt near Bologna to the vicinity of the Po River. The analysis of the profile documents subsidence movements through the last 12,000 years, exceeding − 18 m in syncline areas, with subsidence rates of at least 1.5 m/ka. Anticlines areas experienced a much lower subsidence than the syncline ones. [ABSTRACT FROM AUTHOR]

Lake Ohrid (Macedonia/Albania) is the oldest extant lake in Europe and exhibits an outstanding degree of endemic biodiversity. Here, we provide new high-resolution stable isotope and geochemical data from a 10 m core (Co1262) through the Late Glacial to Holocene and discuss past climate and lake hydrology (TIC, δC, δO) as well as the terrestrial and aquatic vegetation response to climate (TOC, TOC/N, δC, Rock Eval pyrolysis). The data identifies 3 main zones: (1) the Late Glacial-Holocene transition represented by low TIC and TOC contents, (2) the early to mid-Holocene characterised by high TOC and increasing TOC/N and (3) the Late Holocene-Present which shows a marked decrease in TIC and TOC. In general, an overall trend of increasing δO from 9 ka to present suggests progressive aridification through the Holocene, consistent with previous records from Lake Ohrid and the wider Mediterranean region. Several proxies show commensurate excursions that imply the impact of short-term climate oscillations, such as the 8.2 ka event and the Little Ice Age. This is the best-dated and highest resolution archive of past Late Glacial and Holocene climate from Lake Ohrid and confirms the overriding influence of the North Atlantic in the north-eastern Mediterranean. The data presented set the context for the International Continental scientific Drilling Program Scientific Collaboration On Past Speciation Conditions in Lake Ohrid project cores recovered in spring-summer 2013, potentially dating back into the Lower Pleistocene, and will act as a recent calibration to reconstruct climate and hydrology over the entire lake history. [ABSTRACT FROM AUTHOR]

Holocene slackwater deposits along the river channels were used to study the magnitude and frequency of the palaeofloods that occurred prior to gauged and historical data sets all over the world. Palaeohydrological investigations along the Shanxi-Shaanxi Gorge of the middle Yellow River, China, identified palaeoflood slackwater deposits (SWDs) at several sites along the cliffs bordering the river channel. The SWDs are intercalated within Holocene eolian loess-soil profiles and clastic slope deposits. The palaeoflood SWDs were differentiated from eolian loess and soil by the sedimentary criteria and analytical results including magnetic susceptibility and particle-size distribution, similar to the flood SWDs in 2012, which indicated that these well-sorted palaeoflood SWD beds were deposited from the suspended sediment load in floodwaters. They have recorded the extraordinary palaeoflood events which occurred between 3200 and 3000 a BP as dated by the optically stimulated luminescence method in combination with pedostratigraphic correlations with the previously studied Holocene pedo-stratigraphy in the Yellow River drainage basin. Manning slope-area calculations estimate the peak discharged for these palaeoflood events to range from 43,290 to 49,830 m/s. The drainage area of the study site is 489,900 km. It is 2.0-2.5 times the largest gauged flood (21,000 m/s) that has ever occurred since 1934. These events also occurred on Yellow River tributaries, including the Weihe, Jinghe and Qishuihe Rivers. These flood events are therefore considered to be a regional expression of known climatic events in the northern hemisphere and demonstrate Holocene climatic instability. This study provides important data in understanding the interactions between regional hydro-climatic systems and global change in semiarid and subhumid regions. [ABSTRACT FROM AUTHOR]

Based on detailed analyses of cores covering the lagoon of Rasdhoo Atoll, Maldives, six carbonate facies, one soil, and one peat facies have been identified. The abundance of carbonate and rare opaque grains was quantified with a point counter. X-ray diffractometry was used to measure mineralogical composition of samples. The statistical delineation of facies using cluster analysis was based on point count, mineralogical, and textural analyses. In decreasing abundance, the six carbonate facies are classified as mollusk-coral-algal floatstone to rudstone (30 %), mollusk-coral-red algae rudstone (23 %), mollusk-coral-algal wackestone to floatstone (23 %), mollusk-coral wackestone (13 %), mollusk-coral mudstone to wackestone (9 %), and mollusk mudstone (2 %). The carbonate facies represent lagoonal background sedimentation, mostly consisting of fine sediments, and event sedimentation depositing transported coarse-grained reefal components. Fifty-seven carbonate samples and one peat sample were dated radiometrically, covering the Holocene transgression from 10 kyrs BP until today. Comparing the sediment accumulation data of the lagoon with two local sea-level curves, three systems tracts can be identified: (1) a lowstand systems tract characterized by karst and soil deposition >10 kyrs BP, (2) a transgressive systems tract with peat and carbonate separated by hiatus 10-6.5 kyrs BP, and (3) a highstand systems tract dominated by carbonate sedimentation 6.5-0 kyrs BP and further divided into three stages (6.5-3, 3-1, and 1-0 kyrs BP). During the Holocene transgression, sedimentation rates increased continuously to a maximum of 1.4 m/kyr during 3-1 kyrs BP. Modern (1-0 kyrs BP) mean sedimentation rates average 0.6 m/kyr. A simple calculation suggests that two processes (background sedimentation and sand apron progradation) will probably fill up the accommodation space of the lagoon during the Holocene highstand, but these processes will not suffice to fill the larger atoll lagoons of the archipelago. [ABSTRACT FROM AUTHOR]

The history of climate change and related driving mechanisms of the Gonghe Basin, northeastern Qinghai-Tibetan Plateau, China, was reconstructed in the Holocene epoch, based on the comprehensive analysis of multi-proxies consisting of magnetic susceptibility, grain size, and geochemical elements from eolian and peat deposits at different altitudes. The results indicate that Holocene climate change at different altitudes is both consistent and different: a synchronous record of an increased warm-humid phase (10.0-8.5 ka) and a cold phase around 8.2 ka in the Early Holocene; an optimal warm-humid condition in marginal mountains of the Gonghe Basin in the Mid-Holocene; and a gradual decline in temperature and humidity in the Late Holocene. The Gonghe Basin interior in the Mid-Holocene was relatively arid, with increased moisture in the Late Holocene. On this basis, we compared our results to the paleoclimatic record in the low-latitude Asian monsoonal region, which indicates that, in addition to the Asian summer monsoonal strength having influenced regional climate change, the upward and subsidence motion of airflow over the Qinghai-Tibetan Plateau induced by topographic conditions, evaporation, and the feedback effect by the substrate was also influential. The latter was especially important for spatial-temporal differences in Middle and Late Holocene climatic changes at different altitudes. [ABSTRACT FROM AUTHOR]

new method to reconstruct aquatic palaeoenvironments is presented. It is based on a non-metrical 'fish environment reconstruction index' (FERI), calculated for the total fish community recorded at an archaeological site. As an example, a FERI is generated for the Baltic Sea using the ecological requirements of northern European fish species. The present study evaluates the proposed method by using fish bone assemblages from a region (the middle Holocene Baltic Sea coast) with well-studied hydrographic history. The bones originate from consecutive human riparian and coastal settlements of hunter-gatherers. The results obtained for the parameters salinity and sediment structure correlate well with geological knowledge. The new method shows a successive change from freshwater to brackish and finally to nearly marine conditions before, during, and towards the end of the marine transgression that created the present Baltic Sea. Additionally, a shift in the sediment structure from muddy to sandy/rocky conditions is recognisable. [ABSTRACT FROM AUTHOR]

The sedimentary succession of Gallocanta lake, a closed saline lake located in the Iberian Range (NE Spain), documents two successive lacustrine stages: (1) brackish lake stage and (2) shallow saline lake stage. The saline stage corresponds to the present-day situation in which the lake water properties are mainly controlled by a strongly negative annual water balance. The carbonates of the brackish lake stage have relatively constant δ18O values, however, they are rather high (δ18ODo = 2.4‰ and δ18OCc = 4.5‰ mean values) suggesting a hydrologically closed lake with a long residence time of the waters. δ18O values of carbonates from the saline stage vary greatly, and are lighter than in the previous stage (δ18ODo = 0.5‰, δ18OCc = −0.7‰, δ18OMgs = −2.3‰ mean values). These carbonates also precipitated in a hydrologically closed lake, but in equilibrium with a lake water of more variable isotopic composition. The δ13C values for carbonates of both stages reflect a mixing of different pools of carbon, but during saline stage δ13C values have been more controlled by the equilibrium of the lake waters with atmospheric CO2. During the current stage, calcite and dolomite precipitate in Gallocanta lake mainly during spring and summer, although dolomite precipitation is more favoured towards the summer. Magnesite precipitates at the beginning of autumn, when the first rainfall re-dissolves the saline surface crust, producing saline waters with a high Mg2+ content. The isotopic composition of lake waters sampled in 2005 are far higher than those calculated from the carbonates. It is considered that this could be due to two factors: either because there have not been many extremely dry years (like the year 2005) during the development of the lake, or because the physical and chemical characteristics of the lake waters in such conditions are not appropriate for the development of these minerals. [ABSTRACT FROM AUTHOR]

It is a widely held concept that tropical coral reefs in shallower water with branched acroporid corals should accrete faster than those in deeper water dominated by massive corals. Results from a study of Holocene development of the largest Atlantic reef system, including paleo-waterdepth data, challenge these concepts. In Belize barrier and atoll reefs, reef accretion-rates range from 0.46 to 7.50 m/kyr, and average 3.03 m/kyr, as measured along 33 dated reef sections. Interestingly, accretion-rates increase with increasing paleo-waterdepth, and sections dominated by massive corals accumulated even slightly faster than those with branched acroporids. Published data from some other reef locations reveal no significant trends when plotting reef accretion-rate versus paleo-waterdepth, also indicating that the above-mentioned concepts should be questioned. Massive corals apparently are more resistant and accrete in lower disturbance conditions in slightly deeper water (5–10 m) and higher accomodation (space available for sediment deposition) as compared to shallow water (0–5 m) branched acroporids, which repeatedly get broken and leveled out during tropical cyclones. [ABSTRACT FROM AUTHOR]

The study of Upper Quaternary sedimentary sequences in the Pechora Sea by means of vibrocoring revealed three sediment units. The (youngest) sandy unit accumulated in marine environments later than 5000 years B.P. The clayey unit belongs to a pro-deltaic facies, probably formed during Middle Holocene times. The diamict unit formed during Middle/Early Weichselian times, probably has a glacigenic origin and is separated from the clayey unit by a hiatus. The changes in lithology are partly related to changes in Pechora River discharge during late Weichselian/Holocene times. [ABSTRACT FROM AUTHOR]

We present a study based on X-ray chronologies and the stable isotopic composition of fossil Porites spp. corals from the northern Gulf of Aqaba (Red Sea) covering the mid-Holocene period from 5750 to 4450 14C years BP (before present). The stable oxygen and carbon isotopic compositions of five specimens reveal regular annual periodicities. Compared with modern Porites spp. from the same environment, the average seasonal δ18O amplitude of the fossil corals is higher (by ca. 0.35–0.60‰), whereas annual growth rates are lower (by ca. 3.5 to 2 mm/year). This suggests stronger seasonality of sea surface temperatures and increased variability of the oxygen isotopic composition of the sea water due to changes in the precipitation and evaporation regime during the mid-Holocene. Most likely, summer monsoon rains reached the northern end of the Red Sea at that time. Average annual coral growth rates are diminished probably due to an increased input and resuspension of terrestrial debris to the shallow marine environment during more humid conditions. Our results corroborate published reports of paleodata and model simulations suggesting a northward migration of the African monsoon giving rise to increased seasonalities during the mid-Holocene over northeastern Africa and Arabia. [ABSTRACT FROM AUTHOR]