Late Pleistocene Record Research Articles

Mega-Lake in the Kalahari: A Late Pleistocene record of the Palaeolake Makgadikgadi system

A distinct series of beach ridges marking the former shorelines of large inter-connected lacustrine basins in the Kalahari can be clearly identified from Landsat imagery and Shuttle Radar Topography Mission (SRTM) data. These basins, which form the terminal sump of the Okavango system in northern Botswana, are now almost completely dry. During the Quaternary they were intermittently occupied by large stable lake bodies and are thought to have periodically filled to a point of coalescence inundating an area that, at its largest extent, encompassed 66,000 km 2. Poor chronological control has previously limited the utility of this important palaeo-archive. As part of a region-wide lake palaeo-shoreline research programme, a systematic optically stimulated luminescence (OSL) dating programme has utilised a lightweight hydraulic auger to take samples at depth from relict shoreline features. Twenty drill-sites have generated 140 samples for dating, establishing a firm chronology for multiple lake full phases in all three component basins (Ngami, Mababe and Makgadikgadi) of this mega-lake. This paper presents the final set of ages in the programme, derived from four cores from the western and north-eastern shorelines of Makgadikgadi, and uses these ages to establish a chronology of mega-lake high-stands during the last ∼300 ka providing a rare directly dated, long terrestrial record of positive hydrological excursions within the southern hemisphere.

The first record of palaeopathology from the zooarchaeological record of late Pleistocene, southwest Tasmania

AbstractSeveral bones from the Late Pleistocene archaeological site, Kutikina Cave, in southwest Tasmania, show pathological conditions. The majority of these specimens represent Bennett's or red‐necked wallaby (Macropus rufogriseus), with a single specimen of the Common wombat (Vombatus ursinus) recorded. While there has been extensive work in this region of Australia since the early 1980s, this is the first record of palaeopathology from the late Pleistocene of Tasmania, and the first from a human accumulation of predominately macropod material. The palaeopathology raises several questions concerning the mobility of these animals which might have increased their susceptibly to predation, while some of the effected elements are fragmented, suggesting that people utilised these bones despite their deformities. Copyright © 2008 John Wiley & Sons, Ltd.

Late Pleistocene and Early Holocene lake‐level fluctuations in the Lahontan Basin, Nevada: Implications for the distribution of archaeological sites

AbstractThe Great Basin of the western U.S. contains a rich record of Late Pleistocene and Holocene lake‐level fluctuations as well as an extensive record of human occupation during the same time frame. We compare spatial‐temporal relationships between these records in the Lahontan basin to consider whether lake‐level fluctuations across the Pleistocene‐Holocene transition controlled distribution of archaeological sites. We use the reasonably well‐dated archaeological record from caves and rockshelters as well as results from new pedestrian surveys to investigate this problem. Although lake levels probably reached maximum elevations of about 1230–1235 m in the different subbasins of Lahontan during the Younger Dryas (YD) period, the duration that the lakes occupied the highest levels was brief. Paleoindian and Early Archaic archaeological sites are concentrated on somewhat lower and slightly younger shorelines (_1220–1225 m) that also date from the Younger Dryas period. This study suggests that Paleoindians often concentrated their activities adjacent to large lakes and wetland resources soon after they first entered the Great Basin. © 2008 Wiley Periodicals, Inc.

Glen Thirsty: The History and Archaeology of a Desert Well

The archaeology of Glen Thirsty, a desert well in the Amadeus Basin, Central Australia, illustrates the changing relationship between the ranges and desert lowlands during the last 1500 years. Historical records and Aboriginal accounts of the site document the regional importance of Glen Thirsty as one of the few wells in this part of the desert. Archaeological excavations and rock art research show that despite its proximity to Puritjarra with its long, late Pleistocene record of occupation, Glen Thirsty only became an important focus of occupation after 1500 BP. Several lines of evidence independently suggest the establishment and consolidation of a new cultural and economic landscape in the Glen Thirsty area around this time. Growing population pressure and shifts in patterns of land-use and economy in the Central Australian ranges may have provided the impetus for more intensive use of the Glen Thirsty area, although the timing of this was constrained by climatic factors. As a rain-fed well in the lower part of the Amadeus Basin, Glen Thirsty is sensitive to shifts in palaeoclimate and its history reflects changes in regional rainfall patterns during the late Holocene.

Late Pleistocene and Holocene alluvial archives in the Southwestern Mediterranean: Changes in fluvial dynamics and past human response

Cohesive floodplains from the semiarid Southwestern Mediterranean (Morocco, Tunisia) exhibit excellent preservation toward lateral erosion and present a continuous record of Late Pleistocene and Holocene flood dynamics. Holocene mean sedimentation rates and 14C cumulative probability plots from cohesive Tunisian floodplain sequences reveal a coupling with North Atlantic Bond events. Short-term periods of fluvial activity match well with North Atlantic coolings. The findings indicate a strong climatic link from 4.8 ka until today. Unlike fluvial archives from the humid mid-latitudes, semiarid Southwest Mediterranean alluvial archives exhibit phases of increased fluvial dynamics under generally drier conditions. The 14C cumulative probability plot of archeological sites in Mediterranean North Africa indicates correlations with alluvial records. Therefore, prehistoric societies seemed to be very sensitive to past shifts in landscape dynamics.

Fluctuations climatiques enregistrées depuis 20 000 ans dans le remplissage sédimentaire du loch Sunart (Nord-Ouest de l’Écosse)

Over the last 20,000 yr, Loch Sunart has accumulated an important record of Late Pleistocene and Holocene sedimentation characteristic of sea lochs on the western coast of Scotland. A seismic survey conducted using a Seistec Boomer system has demonstrated five distinct sediment-acoustic facies in the loch. These facies have been correlated with sediment sequences identified in a long Calypso core (12 m) acquired from the RV Marion Dufresne. Grain-size and pollen analyses, accompanied with three 14C dates, have yielded information on the patterns of sedimentation since the Late Glacial Maximum. In addition, these data have identified three significant cooling events since the Younger Dryas: 8200, 5500 and 3500 cal. yr BP and the Little Ice Age.

Paleoclimatic variations in West Africa from a record of late Pleistocene and Holocene lake level stands of Lake Bosumtwi, Ghana

A detailed investigation of geomorphological evidence of paleoshorelines and exposed stratigraphic sections of lake deposits, combined with a chronology based on radiocarbon dated charcoal and in-situ 14C dating of wave polished bedrock, provide important new constraints on lake level changes of Lake Bosumtwi, Ghana. Thick sequences of laminated silts, alternating with transgressive sands and deltaic gravels, attest to a long history of climatically controlled lake level variations. The post-glacial rise in lake level began sometime after 16.3 ka, reached stable levels first at 14.5 ± 0.6 ka and then rose again after ca. 14.3 ka. A significant lake level regression spanned the interval from 12.6 ± 0.3 to 11.6 ± 0.5 ka, synchronous with the Younger Dryas. Deep lake conditions were reestablished after ca. 11 ka, at which time the lake overtopped the crater. Overflow continued until 8.8 ± 0.5 ka, when another significant but short-lived regression occurred. Deep, but probably not overflowing conditions were again reestablished by > 7.2 ± 0.3 ka and continued until around 3.2 ± 0.1 ka, when lake level dropped precipitously. Multicentury late Holocene highstands occurred at 2.2 ± 0.1 and 1.7 ± 0.2 ka, although these were significantly lower than those registered in the late glacial and early Holocene. The timing of late glacial events is similar to those recorded elsewhere in Africa and the higher latitudes, and likely reflects the dominant control of high latitude northern hemisphere conditions on the African tropics during the times of large northern hemisphere ice sheets. Mid- to late-Holocene variations appear to be less coupled with changes across Africa and elsewhere, suggesting that regional forcing may be more important during warmer periods.

Paleoecological and paleoenvironmental record of the Late Pleistocene record of Lake Khubsugul (Mongolia) based on ostracod remains

This paper deals with the investigation of the upper 11.6 m portion of a long drill core (KDP-01) taken from the bottom sediments of Lake Khubsugul. Ostracod species and their assemblages recovered from the core were analyzed. The data are compared with the carbonate and sulfate values obtained from bulk sediment, as well as with the flux of the coarse terrigenous fraction (>200 lm) from the same core. Based on the previously calculated depth-age sedi- mentary model, the oldest age of the core studied here is about 230 ka. The four ostracod species recovered in the core are Cytherissa lacustris, Candona lepne- vae, Limnocythere inopinata and Leucocythere sp. According to the distribution of those ostracods, we distinguish four main periods, each of about 50 ka long. Based on the ecological requirements of extant ostracods, two assemblages typifying a low water le- vel and high salinity, on the first hand, and another representing freshwater and high lake level are rec- ognized. The first ''high salinity'' ostracods corre- spond to ''cold'' periods as seen globally, while ''freshwater'' ostracods are associated with intergla- cials. Ostracod valves are absent during interglacial optima. This may be due to chemical dissolution of calcium carbonate related to organic matter decay at the initial stages of diagenesis, probably because during interglacials, in contrast to glacials, organic matter flux reaching the lake bottom were signifi- cantly higher. The periodicity in the development of ostracod species assemblages follows 17, 24 and 47 ka cycles related to orbital forcing. Its diversity is correlated with summer temperature fluctuations in northern altitudes for the past 230 ka. The maximum in species diversity follows the temperature maxima, by about 1.5 and 2 ka. Overall, the data obtained demonstrate a correlation between climatic changes and variations in specific and quantitative ratios of ostracod species during the last 230 ka.

A high-resolution late Pleistocene record of pollen vegetation and climate change from Jingning, NW China

With the support of 18 AM S-C-14 data, a high-resolution pollen record from the Suancigou section at Jingning, Gansu Province was established. Our results showed that the vegetation experienced a series of changes characterized by the alternative growth and decline of forest and steppe components during the period from 44.2 to 11 ka B.P. in the Jingning area. Over the period of 44-29 ka B.P. (MIS3), coniferous forests were flourishing, indicating a humid climate with the temperature being lower than that of the present. Since 23 ka B.P., the vegetation was dominated by steppe-desert steppe under a cold and dry condition, and entered the Last Glacial Maximum dominated by desert steppe. Several periods of the marked decrease in the arborous pollen content in Suancigou well corresponded to the North Atlantic Heinrich events, especially to Heinrich event 3, further supporting that the Heinrich events were well reflected by the pollen record in the Loess Plateau as well.

New Light on the Earliest Hominid Occupation in East Asia

New Light on the Earliest Hominid Occupation in East Asia

Late Pleistocene record of elevated UV radiation in an Antarctic lake

Elevated ultraviolet irradiance (UVR, 280–400 nm) damages DNA and induces reorganisation within biological communities at the Earth's surface. Southern high latitude aquatic ecosystems may be particularly susceptible because of low stratospheric ozone levels and extremely low contents of photoprotective dissolved organic matter (DOM). Surveys of shallow lakes and ponds in eastern Antarctica show that cyanobacteria survive elevated UVR exposure by increasing extra-cellular concentrations of photoprotective compounds, which are preserved in sediments together with photosynthetic pigments. Thus, reconstruction of long-term changes in biological UVR receipt, to provide a context for evaluating the long-term significance of recent changes in ozone column depth, is feasible in Antarctic settings. The sediment in Lake Reid (69° 23′ S, 76° 53′ E), Antarctica, spans the late-Pleistocene and contains UVR-absorbing pigments from benthic cyanobacteria. Here we show that mean exposure of these benthic cyanobacteria to UVR during the last glacial was more than three times higher than during the Holocene, likely due to short periods of photosynthetic activity coinciding with relatively high UVR fluxes, or due to increased UVR transmission to the Earth's surface resulting from changes in external factors such as stratospheric ozone levels, cloud cover and surface albedo.

Fluvial Record of Late Pleistocene and Holocene Geomorphic Change in Northern Tunisia – Global, Regional or Local Climatic Causes?

Fluvial Record of Late Pleistocene and Holocene Geomorphic Change in Northern Tunisia – Global, Regional or Local Climatic Causes?

Multiarchive paleoseismic record of late Pleistocene and Holocene strong earthquakes in Switzerland

A multiarchive approach has been applied to the investigation of the late Pleistocene and Holocene record of strong earthquakes in Switzerland. The geological archives used for this study include active faults, lake deposits, slope instabilities, and caves. In the Basle area, eight trenches were opened across the Basle–Reinach fault, nearby rockfall deposits were systematically investigated, sediment cores were taken from two lakes, and nine caves were studied. In Central Switzerland, five lakes were investigated by means of high-resolution seismic lines and sediment cores. Furthermore, three caves were studied in Central Switzerland. Altogether, the investigations are based on more than 350 km of high-resolution reflection seismic lines, 450 m of core samples, 260 m of trenches, and 245 radiocarbon age determinations. The measured co-seismic displacements along the Basle–Reinach fault supply independent information for the magnitude of the AD 1356 Basle earthquake exclusively based on geological evidence. Deformation features related to three well-documented strong historic earthquake shocks were identified. Deformation features of the AD 1774 Altdorf and AD 1601 Unterwalden earthquakes can be used to calibrate paleoseismic evidence in Central Switzerland. Altogether, traces of 13 earthquakes could be found in the two study areas, all of them with magnitudes M w ∼ 6 or greater. For the first time, the earthquake catalogue for Switzerland can be extended back beyond historic records, into the late Pleistocene, spanning 15,000 years.

An early Pleistocene record of a giant koala (Phascolarctidae: Marsupialia) from western Victoria.

THE pre Holocene-Late Pleistocene record of Phascolarctos in Australia is extremely meagre. There are at least two, possibly three extinct species of Phascolarctos in addition to the extant Phascolarctos cinereus (Black 1999). P. yorkensis (syn. Cundokoala yorkensis; Black and Archer 1997) is known from the Early Pliocene Curramulka Local Fauna, South Australia (SA), and the Late Pleistocene Wellington Caves Local Fauna, New South Wales (Archer et al. 1997; Pledge 1992). P. stirtoni occurs in the Late Pleistocene Cement Mills Local Fauna, Queensland, and is known only from a partial maxilla containing P3-M2 (Bartholomai 1968, 1977). Phascolarctos material from the mid- Pleistocene Victoria Fossil Cave and Spring Cave, Naracoorte, SA, have also been referred to P. cf. stirtoni but remain undescribed (Reed and Bourne 2000; Moriarty et al. 2000). P. maris is known from a single lower molar from the Early Pliocene Sunlands Local Fauna, SA (Pledge 1987). Black (1999) cast doubt on its validity, suggesting its features may fall within the intraspecific variation of P. stirtoni. If P. maris is referable to P. stirtoni it is another South Australian instance of this species, and extends its range back to the Early Pliocene. The new phascolarctid material documented here is from the early Pleistocene Nelson Bay Local Fauna, Portland, Victoria (141o 35? E; 38o 36? S). It is therefore an important additional southern occurrence of a species larger than the living P. cinereus, and is the only pre- Late Pleistocene record of the Phascolarctidae in Victoria.

A record of Late Pleistocene and Holocene carbon accumulation and climate change from an equatorial peat bog (Kalimantan, Indonesia): implications for past, present and future carbon dynamics

AbstractA 9.5 m core from an inland peatland in Kalimantan, Indonesia, reveals organic matter accumulation started around 26 000 cal. yr BP, providing the oldest reported initiation date for lowland ombrotrophic peat formation in SE Asia. The core shows clear evidence for differential rates of peat formation and carbon storage. A short period of initial accumulation is followed by a slow rate during the LGM, with fastest accumulation during the Holocene. Between ∼13 000 and 8000 cal. yr BP, > 450 cm of peat were deposited, with highest rates of peat (> 2 mm yr−1) and carbon (> 90 g C m−2 yr−1) accumulation between 9530 and 8590 cal. yr BP. These data suggest that Kalimantan peatlands acted as a large sink of atmospheric CO2 at this time. Slower rates of peat (0.15–0.38 mm yr−1) and carbon (7.4–24.0 g C m−2 yr−1) accumulation between ∼8000 and 500 cal. yr BP coincide with rapid peat formation in coastal locations elsewhere in SE Asia. The average LORCA (long‐term apparent carbon accumulation rate) for the 9.5 m core is 56 g C m−2 yr−1. These data suggest that studies of global carbon sources, sinks and their dynamics need to include information on the past and present sizeable peat deposits of the tropics. Copyright © 2004 John Wiley & Sons, Ltd.

The influence of biological and environmental factors on the stable isotopic composition of ostracods – the Late Pleistocene record from Lake Albano, Central Italy

The stable oxygen and carbon isotopic composition of ostracod valves is the result of the interaction of several variables. Understanding and identifying the biological and ecological factors influencing the life of these animals improves the interpretation of isotopical data, and leads to better paleoenvironmental reconstructions. Ostracod biostratigraphy and determinations of oxygen and carbon stable isotopes on ostracod valves were carried out on a short sequence of the Last Glacial Maximum from Lake Albano (Central Italy). The oxygen isotopic composition of adults of Candona neglecta ranged between 0.5‰ and 1.5‰, and in Ilyocypris bradyi between –2‰ and –0.5‰ . Isotopic values from adults of C. neglecta fell within the range –1.5‰ to –0.8‰ when corrected for vital effect. The carbon isotopic signal ranged from 9.4‰ to 10.8‰ in adults and juveniles of C. neglecta, and from 9.8‰ to 11.3‰ in I. bradyi. Differences between left/right valve and gender were negligible, whereas there appeared to be a marked influence of life stage and species-specific factors related to vital effect and differences in microhabitat and seasonality. We combined analyses on carbon and oxygen isotopes with information deriving from ostracod ecology to reconstruct short term oscillations in past lake water level. Seasonal changes in either the temperature or the isotopic composition of the lake water were also identified. Relatively high δ18O values in ostracod valves were probably associated with the lake location and source of moisture, while high δ13C values were most probably related to the input of volcanic CO2 into the lake.

Abnormal carbonate diagenesis in Holocene–late Pleistocene sapropel-associated sediments from the Eastern Mediterranean; evidence from Emiliania huxleyi coccolith morphology

In studying the Holocene–late Pleistocene record of the Eastern Mediterranean, considerable Emiliania huxleyi size/shape variation not clearly assignable to primary or secondary calcification was observed. Accordingly, different morphotypes were distinguished by light microscope (LM). A subsequent scanning electron microscope (SEM) analysis of selected samples has indicated that Emiliania huxleyi coccoliths are variably affected by carbonate diagenesis in these sediments. A series of diagenetic stages were qualitatively defined, comprising well-preserved specimens, three overgrowth (OG1 to OG3) and one etching (E1) stage. Comparing SEM and LM observations, a tentative correlation between the E. huxleyi calcified LM-morphotypes and E. huxleyi SEM-overgrowth stages is proposed here. Our study not only indicates that Emiliania huxleyi coccoliths are strongly influenced by carbonate diagenesis, but also that they show effects of carbonate precipitation and dissolution much more clearly than other coccoliths. The relative abundances of the different LM-morphotypes were used to define an E. huxleyi overgrowth index (EXO) that qualitatively estimates carbonate precipitation/dissolution on coccoliths in this sediment. This resulted in definition of five “Diagenetic” intervals (D1 to D5). Deposition of sapropel S1 was a time of good preservation with variable dissolution and no overgrowth of E. huxleyi coccoliths, whereas calcite overgrowth was high during the Last Glacial Maximum (LGM) and interglacial period and, to a lesser extent, during the Younger Dryas and through the last 5 ka.

Stable Carbon Isotope Record of Holocene Environmental Change in the Central Great Plains

Ratios of stable carbon isotopes preserved in soil organic matter record vegetation and climate change and are applicable to the dry environment of the central Great Plains. We sampled two loess sections and one sand sheet swale in southwest Nebraska to study a continuous record of late Pleistocene and Holocene climate change. Carbon isotope (δ13C) data are combined with previously reported and new optically stimulated luminescence (OSL) age control to establish the timing and magnitude of vegetation change. Stratigraphic units studied include the late-Pleistocene Peoria Loess and Brady Soil, Holocene Bignell Loess, and four buried soils within Bignell Loess. Isotope ratios and OSL ages indicate a shift from a C3 to C4 vegetation community during formation of the Brady Soil, reflecting climatic warming spanning the Pleistocene-Holocene transition. By the early Holocene, between 10,100 and 9100 yrs. ago, drought became a persistently recurring feature in the region as indicated by the deposition of Bignell Loess that originated from reworking of devegetated dunes and sand sheet deposits. Periods of rapid loess deposition are marked by an increase in C3 vegetation, which we interpret to indicate vegetation adapted to high rates of landscape disturbance. Conversely, C4 vegetation types dominated during periods of landscape stability and soil formation, when precipitation was sufficient for vegetation to grow on dune fields. We conclude that total annual precipitation and landscape stability are more important factors than seasonality of precipitation and atmospheric CO2 concentration in determining the chronology of C3-C4 vegetation change during the Holocene.

Multiproxy Record of Late Pleistocene–Holocene Climate and Vegetation Changes from a Peat Bog in Patagonia

Pollen assemblage changes and stable hydrogen isotope analysis of mosses (Sphagnum magellanicum and Drepanocladus s.l.) from a bog in Tierra del Fuego, Argentina, provided independent proxies for reconstructing changes in effective moisture and temperature over the past 16,000 cal yr B.P. A deterministic model was used to reconstruct the stable hydrogen isotope composition of meteoric water from the D/H ratios of bog mosses over the last 16,000 years. Abrupt changes in temperature, as recorded in D/H ratios of moss cellulose, were accompanied by synchronous changes in vegetation composition during the late Pleistocene and early and middle Holocene, when moisture levels were lower than today. In contrast, temperature variability during the late Holocene was not accompanied by comparable vegetation changes. In particular, grass pollen (Poaceae) increased during periodic cold spells between 15,000 and 11,000 cal yr B.P., but a cold spell of similar magnitude ca. 2000 cal yr B.P. did not appear to affect vegetation. During the late Pleistocene, the isotopic record from the peat core shows variations similar to the D/H ratios in the Antarctic Taylor Dome ice core. However, the timing of the changes in the Harberton record is more in line with the timing of other Southern Hemisphere records.

The multi-proxy late-Pleistocene and Holocene record from the sediments of the Grand Lac d'Annecy, eastern France

The multi-proxy late-Pleistocene and Holocene record from the sediments of the Grand Lac d'Annecy, eastern France