ALBERT

Description: ABSTRACT Palaeoceanographic changes over the last 6800 years are documented in a diatom record from core MD05–2908 from the southern Okinawa Trough. Changes in diatom components are used to reflect variations in the strength of the Kuroshio Current and the influence of coastal waters, and these changes are compared with records of the East Asian summer monsoon, which exerts an important influence on regional climate and oceanography. A decreasing trend in the contribution of coastal diatoms during the last 6800 years is related to the weakening of the East Asian summer monsoon during the Holocene in response to diminishing insolation and a southward shift in the intertropical convergence zone. Relatively high abundances of the Kuroshio Current indicator species during the intervals 2600–2200 and 4800–3600 cal a BP, and lower abundances during the intervals 3200–2800 and 2200–1300 cal a BP, imply that there is no consistent weakening of the Kuroshio Current during the interval 4500–3000 cal a BP − the Pulleniatina Minimum Event, which is a widespread feature in the East China Sea and the South China Sea. A major reduction in coastal diatoms at 3200 cal a BP and a slight decrease in the Kuroshio Current indicator species during the interval 3200–2800 cal a BP indicate that a palaeoceanographic shift occurred in the southern Okinawa Trough, which coincided with a Northern Hemisphere climatic cooling, denoted the Neoglaciation in Europe. In addition, changes in the freshwater species component of the record are suggested mainly to result from variations in flood frequency in north-eastern Taiwan caused by typhoons. A dramatic increase in the frequency of flood events during the last millennium may have been caused by relatively strong El Niño-Southern Oscillation activity, compared with the more stable period between 6800 and 1000 cal a BP, which experienced a low frequency of flood events.

Description: ABSTRACT We use relative sea-level (RSL) reconstructions and a spatiotemporal statistical model to estimate the rate of uplift of the Cape Fear Arch, a Mesozoic structural high, during the last ∼4000 years. We reconstructed RSL using 12 radiocarbon-dated samples of basal salt-marsh sediment preserved at Elizabeth Creek Marsh on the Cape Fear River. The new data show that RSL rose by ∼3 m during the past ∼4.6 ka at an average rate of 0.67 ± 0.12 mm a −1 . RSL reconstructions from other sites in southern North Carolina (which have rates of 0.91 ± 0.10 to 0.84 ± 0.24 mm a −1 ) probably show ( P  〉 0.9) higher rates of regional RSL rise for the same period, while sites from northern South Carolina (which have rates of 0.72 ± 0.17 to 0.80 ± 0.21 mm a −1 ) probably ( P  〉 0.67) show the same. We attribute the differences between Elizabeth Creek Marsh and neighboring regions to uplift of the Cape Fear Arch, which we estimate to be 0.24 ± 0.15 mm a −1 . Uplift of the arch may be responsible for lower rates of 20 th century RSL rise recorded by the Wilmington tide gauge relative to rates measured elsewhere along the US mid-Atlantic coast.

Description: ABSTRACT Tischoferhöhle and Pendling-Bärenhöhle near Kufstein, Tyrol, are among the only locations where remains of cave bear, Ursus spelaeus -group, were found in the western part of Austria. One sample from each site was radiocarbon-dated four decades ago to ca. 28 14 C ka BP. Here we report that attempts to date additional samples from Pendling-Bärenhöhle have failed due to the lack of collagen, casting doubts on the validity of the original measurement. We also unsuccessfully tried to date flowstone clasts embedded in the bone-bearing sediment to provide maximum constraints on the age of this sediment. Ten cave bear bones from Tischoferhöhle showing good collagen preservation were radiocarbon-dated to 31.1–39.9 14 C ka BP, again pointing towards an age underestimation by the original radiocarbon-dated sample from this site. These new dates from Tischoferhöhle are therefore currently the only reliable cave bear dates in western Austria and constrain the interval of cave occupation to 44.3–33.5 cal ka BP. We re-calibrate and re-evaluate dates of alpine cave bear samples in the context of available palaeoclimate information from the greater alpine region covering the transition into the Last Glacial Maximum, eventually leading to the demise of this megafauna.

Description: ABSTRACT This study documents changes in the sedimentary environment on the outer continental shelf off south-west Spitsbergen during the last ∼14 000 cal a BP using sedimentological, mineralogical and geochemical data from a sea-bed sediment core. We use the sortable silt fraction to infer fluctuations of near-bottom current speed and determine sediment provenance and sediment transport paths. For most of the record length, sediments were derived from distal sources by the West Spitsbergen Current (WSC) and the East Spitsbergen Current (ESC). However, before ∼12 000 and after ∼1800 cal a BP sediments were also sourced from proximal sources in south-west Spitsbergen. The slowest near-bottom currents were recorded between 10 300 and 9700 cal a BP when an increase in water stratification occurred, probably due to the strengthening of the ESC and an associated reduction in the northward water and heat flux. Near-bottom currents related to WSC activity were at their maximum between 9000 and 7500 cal a BP, i.e. during a period of elevated water temperature, probably resulting in maximum relative heat fluxes to the Arctic.

Description: ABSTRACT Excavations across a source-bordering dune overlooking the Hawkesbury River in north-west Sydney, Australia, suggest initial occupation of the region by at least 36 ka, with variable but uninterrupted use until the early Holocene; following abandonment, the site was then re-occupied by ∼3 ka. Along with a handful of other sites, the results provide the earliest reliable evidence of permanent regional populations within south-eastern Australia, and support a model in which early colonizers followed the coastal fringe with forays along the main river systems. The evidence is consistent with the demographic model of Williams, 2013 ( Proceedings of the Royal Society Series B 280 : 20130486), which suggested low, but established regional populations before the Last Glacial Maximum (LGM), a population nadir following the LGM and increasing use of the region from ∼12 to 8 ka. The site exhibits increased use at the onset and peak of the LGM, and provides an example of a cryptic refuge as defined by Smith, 2013 ( The Archaeology of Australia's Deserts . Cambridge University Press: New York). Specifically, changing artefact densities and attributes show the site was used repeatedly, but for shorter periods through this time, and suggest it formed one of a series of key localities in a point-to-point (rather than home-base) subsistence strategy. This strategy was maintained until the site's abandonment in the early Holocene, despite changing population and climatic conditions through the Terminal Pleistocene.

Description: ABSTRACT Two discontinuous tephra layers were discovered at Burney Spring Mountain, northern California. Stratigraphic relationships suggest that they are two distinct primary fall tephras. The geochemistries of these tephras from electron probe microanalysis were compared with those of known layers found in the area to test for potential correlations, using clustering analysis on geochemistry. In most cases, geochemical data from a tephra layer can be assigned to a single cluster, but in some cases the analyses are spread over several clusters. This spreading is a direct result of mixing and reworking of several tephra layers. The mixing, in turn, appears to be related to the influence of wind in a marshy environment.

Description: ABSTRACT Lophelia pertusa is a colonial cold-water coral species with a wide spatial distribution in recent marine waters. Analysing the chemistry of its skeleton allows reconstruction of environmental parameter variations. While numerous studies have attempted to interpret such analyses, little information is available on the microstructures of Lophelia pertusa and their temporal constraints. This study introduces newly recognized microstructures in the coral wall following growth along the radial axis. The thicknesses of these ‘micro-layers’ are correlated with strontium concentrations and can be used to estimate seasonal growth rates of single polyps from the colony. We propose that each of these micro-layers represents a period of 1 month of mineralization and can locate two decreasing periods in growth rate during a year: one caused by limited food availability during winter months and one in autumn linked to gametogenesis. High-frequency study of strontium concentrations using this interpretation shows a lunar cycle. We demonstrate that while the micro-layers are present in all L. pertusa specimens from four locations in the Atlantic Ocean and the Mediterranean Sea, growth patterns reveal a complex organization that limits their visibility. Strontium fluctuations, however, appear to be a promising mechanism by which to establish a temporal calibration.

Description: ABSTRACT The British Isles have been affected by as many as 30 glaciations during the Quaternary. However, the evidence for pre-Devensian glaciations in upland regions is scarce. Understanding the extent and timing of earlier upland glaciations is essential for modelling the long-term evolution and sensitivity of the British Ice Sheet. Caves, being protected from surface erosion and weathering, can preserve evidence of earlier glaciations in the form of speleothem and sediment archives. The ∼70-km-long Ogof Draenen cave system in South Wales, UK, contains multiple cave levels related to changes in the surface topography and drainage during the past 0.5 Ma. The cave contains evidence of massive influxes of sediment that were sufficient to choke the cave and alter the underground drainage. Analysis of the cave sediments, passage morphology and geometry suggests the cave once acted as a subterranean glacial spill-way before being overridden by ice. Speleothem U-series data demonstrate that this sediment influx occurred before Marine Isotope State (MIS) 9, probably during the Anglian glaciation (MIS 12). Evidence from Ogof Draenen indicates the impact of subsequent glaciations on the landscape evolution of the region was minimal and that much of the surface topography dates from the Anglian. Copyright © 2014 British Geological Survey (NERC). Journal of Quaternary Science © 2014 John Wiley & Sons Ltd.

Description: ABSTRACT Regional changes in vegetation and environment in the last 16 ka have been reconstructed from Micalong Swamp and Willigobung Swamp (35°S) on the western Southern Tablelands of New South Wales (NSW). Micalong Swamp lies at 980 m above sea level (a.s.l.), which is close to the subalpine treeline at this latitude. Willigobung Swamp (780 m a.s.l.) approaches the modern ecotone between dry and wet montane forest formations. The sites are sensitive to shifts in temperature and precipitation and are the first reported pollen records from the western montane slopes of NSW. A radiocarbon-based chronology indicates that Micalong Swamp was a swampy, gravel floodplain surrounded by alpine grassland before 16.1 ka. Subalpine woodland may have become established at 1000 m by 16–14 ka. Organic fen sedimentation developed 〈11.8 ka at Willigobung, and ∼11.7 ka at the higher elevation Micalong Swamp. Wet forest elements were present at both sites around 10 ka and persisted for 3–4 ka. Sedimentation in a shallow lake or fen between 10 and 8 ka supports this evidence for wetter conditions in the early Holocene. In the late Holocene an expansion of subalpine flora between 2.7 and 0.9 ka preceded by shallow lake/fen sedimentation is consistent with regional evidence for neoglacial cooling.