Showing papers in "Quaternary Research in 1981"

TL;DR: In this article, a model that describes the relationship between basin size and pollen source area and predicts the proportions of local, extralocal, and regional pollen sampled by lake basins of different size is presented.

TL;DR: In this article, two reconstructed histories of the monsoon rainfall in Rajasthan show that the Monsoon was weak or absent in latest glacial time, and that fresh water lakes formed in dune fields and the pollen rain preserved in these reservoirs provides a basis for the reconstruction of monsoon history.

TL;DR: In this article, relative-age criteria permit deposits of successive Andean glacier advances in the southern Lake District of Chile to be divided into four mappable drift sheets, the oldest two of which overlie Tertiary bedrock along the eastern flank of the Cordillera de la Costa.

TL;DR: In this article, it was shown that half of the Northern Hemisphere ice volume at the last glacial maximum had disappeared by 13,000-16,000 yr B.P., despite the still-extensive limits of the ice sheets.

TL;DR: In this paper, it was shown that the rate of weathering becomes constant only when an equilibrium thickness of the residue is reached, i.e., when the residues are relatively stable chemically, and because physical removal of residues below the ground surface is slight.

TL;DR: Three unstable ephemeral-stream channels (arroyos) were resurveyed to provide data on the rates and mechanics of erosion and sedimentation processes during periods ranging from 14 to 22 yr.

TL;DR: In this article, a model for predicting the growth and decay of ice sheets based on the astronomical theory of climate change is presented, which is used to isolate the role of the ice-sheet physics and earth response under varying ice load.

TL;DR: In this paper, single sample magnetic susceptibility measurements are used to correlate synchronous levels in 16 cores of dated (210Pb, 137Cs) recent sediment taken from the deep and oligotrophic Llyn Peris, N. Wales, in order to provide a basis for calculating total sediment and chemical influx through time.

TL;DR: In this paper, preserved pollen records from Everitt Lake, Nova Scotia, are analyzed as time series to reveal the post-fire responses of individual tree taxa, thus suggesting mechanisms by which fire, competition, and climate combine to produce long-term forest composition changes.

TL;DR: Temperatures for the past 2700 yr are estimated using well-dated pollen data from northwestern lower Michigan as mentioned in this paper, where the pollen data were sampled from sediment cores of four lakes along a 75-km transect, with fine-grained morainic soils around the two western lakes and sandy outwash soils surrounding the lakes to the east.

TL;DR: In this paper, the authors synthesize radiocarbon-dated and identified fossil wood and macrofossils from Alaska and northwest Canada and are augmented by results of palynological studies in an effort to show the persistence of some, and total extinction of other, tree and large shrub species.

TL;DR: Pollen and macrofossil analyses of a core spanning 26,000 yr from Davis Lake reveal late Pleistocene and Holocene vegetational patterns in the Puget Lowland.

TL;DR: The geomorphic and stratigraphic history of six coastal embayments has been studied in the vicinity of Newcastle, New South Wales (N.S.W), Australia, in order to determine modes of deposition, and the degree to which marine and estuarine deposits can be correlated and dated.

TL;DR: In this article, the uppermost 2 to 3 m beneath Pleistocene surfaces indicate permafrost at 1340 m and higher elevations in the intermontane and piedmont plains of Wyoming during the Wisconsin, and perhaps earlier, glacial maxima.

TL;DR: In this article, the sequence of vegetation phases in the late Glacial was studied in a sediment section from the bog Tourbiere de Chirens by means of pollen analysis and the observed 18O/16O variations agree well with the climatic history as deduced from pollen analysis.

TL;DR: In this paper, a Q-mode analysis of four key pollen records covering the last interglacial-glacial cycle resulted in four leading components: Nothofagus dombeyi type, Gramineae, Weinmannia-Fitzroya type, and Myrtaceae.

TL;DR: Kylen Lake, located within the Toimi drumlin field, is critically positioned in relation to Late Wisconsin glacial advances, for it lies between the areas covered by the Superior and St. Louis glacial lobes between 12,000 and 16,000 yr B.P as mentioned in this paper.

TL;DR: An energy flux balance model has been developed which treats evaporation as a function of air temperature, surface water temperature, precipitable water aloft, the amount, height, and type of sky cover, and the optical air mass as mentioned in this paper.

TL;DR: In the late Pleistocene, the northern Chihuahuan desert was dominated by woodlands of pinon pines, junipers, and oaks as discussed by the authors, and a paleoclimate is postulated that had the following characteristics: increased winter precipitation from Pacific frontal sources, reduced summer temperatures and precipitation, and milder winter temperatures due to a reduced frequency of Arctic airmass incursion.

TL;DR: In this paper, the authors used the CLIMAP date of 18,000 yr ago as a reference level to review the distribution of major vegetational formations in central and eastern United States and found that the boreal forest to the south in the central United States was dominated by spruce; the jack pine that had prevailed during previous times was apparently eliminated by the time the ice reached its maximum.

TL;DR: In this article, a number of factors including volcanic glass composition and exposure-temperature history must be known in order to relate hydration thickness to age, including chemical analysis or the refractive index of the glass.

TL;DR: Early Pliocene and late Pleistocene littoral and marine deposits contain a characteristic fossil assemblage: Strombus coronatus, Nerita emiliana, Gryphaea virleti, Patella cf. intermedia, and Rothpletzia rudista as discussed by the authors.

TL;DR: A 14m core of lake sediments from St. Paul Island yielded a long environmental history of the south coast of the Bering land bridge as discussed by the authors, and the remaining radiocarbon chronology, coupled with a time-stratigraphic pollen-zone boundary suggests that the record penetrates to the mid-Wisconsin interstadial.

TL;DR: New cross sections and dates from along the Pomme de Terre River clarify the complex local history of valley development and floodplain sedimentation as discussed by the authors, and the observed history begins with a series of ancient bedrock strath terraces that record past bedrock valley positions at 15.5 to 58 m above the modern bedrock floor.

TL;DR: The postglacial history of Lake Manitoba has been deduced from a study of the changes in physical, mineralogical, and chemical variables in sediment cores collected from the lake as discussed by the authors.

TL;DR: A number of ancient shorelines formed by late-Pleistocene proglacial lakes have been found in eastern upper Michigan as mentioned in this paper, and these shorelines delimit several water planes, the uppermost of which is correlated with the Main Lake Algonquin stage.

TL;DR: It is suggested that both aquatic and terrestrial insects are good indicators of macroclimate, given the present-day distributions and feeding habits of these river, lake, and terrestrial taxa in the Pleistocene Scarborough Formation.

TL;DR: The Canyon Creek vertebrate-fossil locality is an extensive road cut near Fairbanks that exposes sediments that range in age from early Wisconsin to late Holocene as discussed by the authors.

TL;DR: The Norwood site in Sibley Co., Minnesota, contains 1.6 m of silt resting on till and overlain by peat, which has been radiocarbon dated at 12,400 ± 60 and the top at 11,200 ± 250 yr B.P as discussed by the authors.