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Continuous multiproxy data were generated to understand the mid-late Holocene palaeoenvironmental history of the Kashmir Valley and the biogeochemistry of Wular Lake, India. For this purpose, geochemical and stable isotopic analyses were carried out on sediment samples retrieved from a 160 cm long trench excavated on the eastern bank of Wular Lake located in the Union Territory of Jammu and Kashmir, India. The chronology of the sediment strata developed using 14C dating by accelerator mass spectrometry covered the last ~5600 yr BP. Our results indicated the occurrence of an extended dry climate phase from 4600 to 3800 yr BP, which coincided with the widely recognised Meghalayan Stage, when major civilisations like the Harappa and the Akkadian were known to collapse. The lake biogeochemistry revealed dominance of the emergent macrophytes during this stage. Another dry phase was observed between 3100 and 2200 yr BP. This dry phase peaked at around 2900 yr BP, coinciding with Bond Event 2. Wular Lake faced nutrient limitation due to low runoff around 2500 yr BP caused by the persistent dry and cold climate. Geochemical signatures revealed that anthropogenic activities during the last two millennia might have significantly influenced erosion in the catchment area. [ABSTRACT FROM AUTHOR]

The sediment record from Lake Victoria is an important archive of regional environmental and climatic conditions, reaching back more than 15,000 cal. years before present (15 ka BP). As the largest lake by area in East Africa, its evolution is key to understanding regional palaeohydrological change during the late Pleistocene and Holocene, including controls on the Nile River flow. As well as important palaeoenvironmental proxies, the lake contains a unique record of explosive volcanism from the central Kenyan Rift, in the form of fine-grained volcanic ash (tephra) layers, interpreted as airfall deposits. In the V95-1P core, collected from the central northern basin of the lake, tephra layers vary in concentration from 10s to 10s of 1000s of glass shards per gram of sediment. None of the tephra are visible to the naked eye, and have only been revealed through careful laboratory processing. Compositional analyses of tephra glass shards has allowed the tephra layers to be correlated to previously unrecognized eruptions of Eburru volcano around 1.2 and 3.8 ka, and Olkaria volcano, prior to 15 ka. These volcanoes lie ~300 km east of the core site in the Kenyan Rift. Our results highlight the potential for developing cryptotephra analysis as a key tool in East African palaeolimnological research. Tephra layers offer opportunities for precise correlation of palaeoenvironmental sequences, as well as windows into the eruption frequency of regional volcanoes and the dispersal of volcanic ash. [ABSTRACT FROM AUTHOR]

A limestone cave on the lower slopes of the southeastern Australian high country reveals a deep, stratified deposit dated from ca. 14,000 to 2000 cal. BP and rich in predominantly non-cultural faunal remains. Located in a sensitive ecological area between the Australian Alps and the Southern Tablelands, the site provides a valuable chronological archive for the interpretation of local environmental change using the faunal record as a proxy, in particular native rodents and other small mammals. Inferred palaeoenvironmental trends include the cessation of periglacial conditions in the surrounding ranges during the Terminal Pleistocene; a shift to warmer conditions and the establishment of forest and wetland habitats from around 13,500 to 10,000 cal. BP, with a significant decline in cold-adapted species at ca. 11,500 cal. BP and a period of significant taxon fluctuation and extinctions corresponding to a possible peak in warm and moist conditions (a 'Holocene Optimum'), beginning around 8000 cal. BP and lasting perhaps 1500 to 2000 years. Complications to the relatively steady and continuous chronostratigraphy, formed from an AMS radiocarbon sequence from sedimentary charcoal, arose from the presence of several teeth of extinct sthenurine megafauna. These were resolved with direct U-series analysis to establish their much greater antiquity and comparison of the sthenurine teeth with teeth of extant macropodids from the same deposit through fluoride absorption analysis, which also identified the megafauna teeth as anomalous to the sequence. The site provides an important case study for the interpretation of megafauna remains in stratified sedimentary deposits, especially for sites that appear to contain evidence for the co-occurrence of megafauna and humans in primary contexts. [ABSTRACT FROM AUTHOR]

A multiproxy approach has been performed on sediments collected by gravity and box coring at the inner part of the Ría de Muros to reconstruct its environmental evolution since the Middle Holocene. This reconstruction is based on the chronological framework provided by radiocarbon dating of foraminifera samples. Three distinct facies were identified in the sedimentary record. The oldest, characterised by coarse-grained sediments and a strong terrestrial signature, is likely linked to the progradation of the delta-fan of the Maior River during a period of standstill subsequent to the Holocene sea-level maximum (ca. 6900 cal yr BP). The second facies started to deposit approximately 2865 ± 335 cal yr BP and is characterized by the deposition of finer-grained, marine-influenced sediments linked to a period of reduced local hydrodynamic energy, most likely due to a progression of sea-level rise. The third facies started to deposit approximately 1720 ± 180 cal yr BP and shows a progressively stronger marine influence. The characteristics of the last facies are explained as the result of the added effects of progressive sea-level rise and an intensified upwelling reaching the inner ría. This facies shows clear anthropogenic features since 555 ± 65 cal yr BP, associated with the important mediaeval development of the area. The obtained results suggest that high-resolution studies are key to resolve possible sea-level oscillations during the late Holocene and allow distinguishing local/regional changes superimposed to the global signals. [ABSTRACT FROM AUTHOR]

Three marine inlets across the southern Hikurangi margin, New Zealand, are investigated for evidence of palaeocoseismic subsidence, a signal associated with great subduction earthquakes. Microfossil analyses and radiocarbon-dated shells from core samples show that none of the sites have subsided since 2000 cal yr BP. Pauatahanui Inlet has remained at the present elevation since 7000 cal yr BP, while Big Lagoon and south-eastern Lake Wairarapa both subsided c. 4 m between 6000 and 2000 cal yr BP. At Big Lagoon most or all of the subsidence was tectonic. At south-eastern Lake Wairarapa, however, sediment compaction caused some or all of the subsidence. Neither of the subsided sites contain sedimentary or palaeoenvironmental transitions suggestive of sudden, coseismic relative sea-level rise. One possible palaeotsunami deposit was found at Big Lagoon, coincident with a colluvial deposit, and two liquefaction layers were identified in south-eastern Lake Wairarapa. [ABSTRACT FROM AUTHOR]

This article outlines the results of one of the aspects of a multidisciplinary project currently conducted in the upper part of the basin of the Western Dvina River in North-Western Russia. The project was targeted at prehistoric lake dwelling sites in the valley of Serteya River, a small tributary of the Western Dvina, and aimed at the precise dating of the initial transition from hunting-gathering to agriculture in that area. The methods used included pollen, diatom and geochemical analyses under strict time control provided by radiocarbon dating. The initial settlement emerged at c. 6200 cal. BC, when the valley was filled by a fresh water lake with a relatively high lake-level. The initial indices of agriculture became perceptible in the deposits of Usvyatian Culture (4600-3400 cal. BC), featuring large-scale constructions of pile-dwellings. Indices of swidden type agriculture became apparent in the deposits of Zhizhitsian Culture, 2300-2200 cal. BC.