Showing papers in "Quaternary Research in 1996"

TL;DR: In this paper, climate variability on the Yucatan Peninsula during the past 3500 yrs is reconstructed from the measurement of δ18O in monospecific ostracods and gastropods in a 6.3m sediment core from Lake Punta Laguna, Mexico.

TL;DR: In this paper, the accuracy of Arctic lake chronologies has been assessed by measuring the 14C activities of modern carbon sources and applying these isotopic mass balances to dating fossil lake materials.

TL;DR: In this paper, the authors evaluated the ages of soil organic matter with a model which incorporates the dynamics of the 14C content of the organic matter and found that the deviation of the measured 14C age from the true age of soil formation could differ significantly among different soils or soil horizons.

TL;DR: In this article, the influence of the glacial anticyclonic circulation attenuated through the late glacial period, and the Westerlies gradually shifted northward, such that drier conditions south of the ice sheet were confined to a progressively narrower zone and the Mediterranean became drier.

TL;DR: This article used the GISP2 ice core to develop a continuous record of explosive volcanism over the past 110,000 yr. They identified ∼850 volcanic signals with sulfate concentrations greater than that associated with historical eruptions from either equatorial or mid-latitude regions that are known to have perturbed global or Northern Hemisphere climate, respectively.

TL;DR: In this paper, the Saksunarvatn Ash is reported for the first time from western Norway, and both tephras are dated precisely by AMS analyses of terrestrial plant material and lake sediment at Krakenes.

TL;DR: In this paper, phytoliths and macroscopic charcoal from natural soils near Manaus, Brazil were analyzed to study the evolution of the central Amazonian terra firme forest during the Holocene.

TL;DR: The vegetation and climate of the Pampa grassland, Argentina, during the late Quaternary are reconstructed from pollen recovered from dated stratigraphic sections from arroyo walls and from archaelogical excavations as mentioned in this paper.

TL;DR: In this article, high-resolution paleomonsoon proxy records from peat and eolian sand-paleosol sequences at the desert-loess transition zone in China denote a rapid oscillation from cold-dry conditions (11,200-10,60014C yr B.P.) to cool-humid conditions (10, 600 −10,200 14C yrB.P.).

TL;DR: In this paper, a postglacial precipitation δ18O history has been reconstructed for two regions of Canada, showing that longterm shifts in the oxygen-isotope composition of annual precipitation (δ18Op) in southern Ontario appear to have occurred with a consistent isotope-temperature relation throughout the past 11,50014C yr.

TL;DR: It is shown that defoliation can affect ecosystems for centuries, especially when long-lived tree species are involved, as well as how it affected hemlock reproductive capacity and pollen productivity.

TL;DR: This article found that brown bears of the Alexander Archipelago have continuously inhabited the archipelago for at least 40,000 yr and that habitable refugia were therefore available throughout the last glaciation.

TL;DR: Stable isotopes, geochemical, lithological, and micropaleontological results from cores from the far northwest (FNW) Pacific and the Okhotsk and Bering seas are used to reconstruct the regional environment for the last glaciation, the deglacial transition, and the Holocene.

TL;DR: The ages of some tsunami deposits can be determined by optical dating, a key requirement being that the deposits are derived from sediment that was reworked and exposed to daylight by tidal currents, waves, wind, or bioturbation during the last years before the tsunami as discussed by the authors.

TL;DR: In this paper, morphometric analyses show quantitative differences in anatomical characters of wood and charcoal between wild and cultivated olive, showing that growth ring width and number of vessels per group are both significant criteria for discriminating between wild-and cultivated olive.

TL;DR: In this article, an exceptionally rich paleontological site containing thousands of mammalian fossils and well-dated with 18 radiocarbon samples provides evidence of late-Holocene ecological response to climatic change in northern Yellowstone National Park, Wyoming.

TL;DR: The discovery of a prehistoric mummified corpse at the upper edge of the accumulation area of an alpine glacier, together with its unique set of artifacts, provided new information on glacier dimensions during the little-known phases of major glacier shrinkage that characterized the warmest parts of the Holocene as discussed by the authors.

TL;DR: A 13,000-year history of late-Quaternary vegetational and climatic change has been derived from lacustrine sediments from Pleasant Island in the Glacier Bay region of southeastern Alaska.

TL;DR: In this paper, the age of the Umivit/Keglen and Orkendalen moraine systems close to the present ice sheet margin in central West Greenland has been investigated.

TL;DR: Aspartic acid (Asp) racemization occurs at a significantly higher rate than isoleucine epimerization and consequently provides better temporal resolution of Arctic marine deposits as discussed by the authors.

TL;DR: In this paper, the authors applied the Mutual Climatic Range (MCR) analysis to 20 fossil beetle assemblages from 11 sites dating from 14,500 to 400 yr B.P. The analysis yielded estimates of mean July and mean January temperatures.

TL;DR: In this article, the authors proposed a new sea-level and δ18O curve for the past 34,000 yr, based on uranium-thorium chronology, for the southwestern part of the Indian Ocean.

TL;DR: An analysis of a sediment core from Farewell Lake in the Alaska Range has been conducted by as discussed by the authors, showing that the lake was substantially shallower and more productive between 11,000 and 8500 yr B.P.

TL;DR: In this paper, Radiolarian microfossil-based temperature reconstructions for the eastern North Pacific spanning the past 20,000 yr to examine possible correlations and linkages between continental climate change and changes in sea surface temperature (SST) in the northeastern Pacific Ocean on millennial time scales.

TL;DR: The age of the Sheep Creek tephra (SCt), a widespread marker ash bed in eastern Alaska and western Yukon Territory, has been ambiguous and controversial as discussed by the authors, and three reliable thermoluminescence age estimates from bracketing loess near Fairbanks that imply a deposition age of about 190,000 ± 20,000 yr for SCt.

TL;DR: A calcium oxalate (whewellite)-rich crust was found on exposed limestone surfaces in dry rock and open air shelters in the Lower Pecos region of southwest Texas.

TL;DR: Sedimentologic, rock-magnetic, and X-ray fluorescence data from two marine sediment cores in Hudson Strait suggest that a red, hematite-rich clay layer was deposited throughout the strait during the final collapse of the Laurentide Ice Sheet in the vicinity of northern Hudson Bay and western Hudson Strait.

TL;DR: A10Be inventory and 14C ages of material from a core from northernmost Illinois support previous interpretations that this area was ice free from ca. 155,000 to 25,000 yr ago as discussed by the authors.

TL;DR: In this article, an alternative method for reconstructing paleowinds of the last glacial maximum in these latitudes was recently put forward, and uses sedimentological records from the Canary Islands and coastal regions of Morocco.

TL;DR: In this paper, the authors measured the 14C ages of detrital mollusk shells and coral in such deposits at the Penghu Islands and found that the best approximation of depositional age was derived from the ages of mollusks.