Showing papers in "Quaternary Research in 1973"

TL;DR: The core Vema 28-238 as discussed by the authors preserves an excellent oxygen isotope and magnetic stratigraphy and is shown to contain undisturbed sediments deposited continuously through the past 870,000 yr.

TL;DR: In the Boundary Waters Canoe Area, fire was a major ecosystem factor before European man arrived, and even before early man migrated to North America as discussed by the authors, and the whole ecosystem was fire-dependent.

TL;DR: In the St. Elias Mountains in southern Yukon Territory and Alaska, C14-dated fluctuations of 14 glacier termini show two major intervals of Holocene glacier expansion, the older dating from 3300-2400 calendar yr BP and the younger corresponding to the Little Ice Age of the last several centuries.

TL;DR: In this paper, indirect evidences of buring in vegetation and soils, and recent direct observations of fires, are reviewed, and it is concluded that fire should be viewed as a normal ecological process in the boreal forest.

TL;DR: A detailed record of the past 1000 yr shows that the average frequency of fire is approximately 60-70 yr, with a range of about 20-100 yr as discussed by the authors, which is consistently higher than that for the last 500 yr, although the fire frequency for the two periods was not appreciably different.

TL;DR: In this paper, remains of dead bristlecone pine (Pinus longaeva Bailey) are found at altitudes up to 150 m above present treeline in the White Mountains.

TL;DR: In the last 150,000 years, bottom water characteristics have shifted back and forth in this interval of time and therefore, therefore, bottom circulation partakes in the well-documented shifts recorded for surface waters of the North Atlantic as mentioned in this paper.

TL;DR: A 9300 yr-old zone of disseminated volcanic ash in North Atlantic sediments between 45° N and 65° N provides a time-synchronous reference layer against which we have compared the stratigraphic level of deglacial warming of ocean surface waters.

TL;DR: In this paper, fire has both positive and negative effects on esthetic and recreational values in the Alaskan taiga ecosystem and its effect on permafrost and the soil nutrient cycle.

TL;DR: The impact of fire on the environment of the various Sierran conifer forests varies with intensity and frequency as discussed by the authors, however, fire (1) prepares a seedbed; (2) cycles nutrients within the system; (3) adjusts the successional pattern; (4) modifies conditions affecting wildlife; (5) influences the mosaic of age classes and vegetation types; (6) alters the numbers of trees susceptible to disease and insects; and (7) both reduces and creates fire hazards.

TL;DR: In this paper, the authors describe the relationship between fire and unmanaged ecosystems, so that strategies can be determined that will provide a more nearly natural incidence of fire in these coniferous ecosystems.

TL;DR: A simplified and more accurate version of the quantitative paleoenvironmental method proposed by Imbrie and Kipp (1971) is described in this article, which is based on untransformed rather than transformed species per cent data.

TL;DR: In this article, the authors attempted to relate current knowledge of sea-level history in Beringia to the Broecker-van-donk concept of climatic and sea level history, and showed that sea level probably fell to about −135 m in the Bering Sea area during the maximum phase of the penultimate glaciation.

TL;DR: The earliest and most extensive Holocene glacier expansion was the Satanta Peak advance, which deposited multiple terminal moraines near present timberline shortly before 9915 ± 165 BP.

TL;DR: In this paper, fire history investigations in the Jackson Hole area of northwestern Wyoming reveal that most current stands of aspen and lodgepole pine regenerated following extensive fires between 1840 and 1890 and that widespread fires occurred in the 1600s and 1700s.

TL;DR: In this paper, the displacement of boreal forest species by over 1000 km during full-glacial time appears to have been azonal, and there is good evidence to suggest a significant mid-Wisconsin interstadial (23,00036,000 BP) characterized by a more temperate biota.

TL;DR: In this paper, the uplift of Barbados during the past 130,000 yr has been at nearly constant relative rates in the Clermont and Christ Church standard traverses.

TL;DR: A fire occurred on the average of every 8.8 yr with “major” fires every 10.3 yr as discussed by the authors at State Park and twenty-one of these fires were of major consequence.

TL;DR: In this paper, radiocarbon dates on molluses in marine facies associated with glacial deposits in northern Cumberland Peninsula indicate both main fiord (Laurentide) ice and local glaciers remained at their late Wisconsin maxima until ca. 8000 BP.

TL;DR: In this paper, an absolute chronology is estimated by linear interpolation between levels dated by 14C or by stratigraphic correlation with other radiometrically dated climatic records.

TL;DR: Stratigraphic palynology and radiocarbon chronology of two bogs and a lake on the northwestern Olympic Peninsula serve to record the environmental sequence postdating the Fraser maximum of the Juan de Fuca lobe as discussed by the authors.

TL;DR: A summary assessment of selected early man sites in various parts of America, the environment of the Venezuelan coastal plain is discussed in order to evaluate the stratigraphy and radiometric dating of the Taima-Taima site, near Coro, Venezuela, where mammals, many now extinct, were killed by people making El Jobo points about 13,000 years ago.

TL;DR: A quantitative study of the distribution of Radiolaria in surface sediments of the North Pacific has demonstrated the feasibility of utilizing complete radiolarian thanatocoenoses as indicators of past oceanographic conditions as mentioned in this paper.

TL;DR: Spectral analysis of deep-sea sediments indicates that the fluctuations in compositional parameters are not random fluctuations with time, and that the spectrum has significant peaks representing periodicities in the data of 380, 1300 and 2600 years as mentioned in this paper.

TL;DR: In this paper, the distributions of the radiolarian assemblages in the Northeastern Pacific Ocean were determined and correlated with the average summer temperature of the near surface waters of this region.

TL;DR: In this paper, a transfer function relating the assemblages in core tops to the temperature at 200 m is applied to five cores, and three zones of increased calcium carbonate dissolution occur in these three cores.

TL;DR: By He-U dating of corals from elevated Pleistocene reef tracts on Barbados, the authors have extended back to the Middle Pleistonian the high sea stand chronology previously deduced by Th 230 -U dating.

TL;DR: Bed I in the Olduvai Gorge spans the interval from about 1.7 to 2.0 m.y.a. as mentioned in this paper and all evidences of hominid activity at Bed I are within the latter half of this period.

TL;DR: In this paper, the authors used transfer functions developed in a study of surface sediments to estimate oceanographic conditions in cores containing late Pleistocene radiolarian faunas and found that conditions as warm as the Holocene were rare during the past 800,000 yr, and that the region experienced marked near surface temperature drops correlative with Caribbean and continental records for the past 250,000 years.