scholarly journals Paleosols in the Transantarctic Mountains: indicators of environmental change

Solid Earth ◽  
2013 ◽  
Vol 4 (2) ◽  
pp. 451-459 ◽  
Author(s):  
J. G. Bockheim
Keyword(s):  
Volcanic Ash ◽  
Late Quaternary ◽  
Dry Valleys ◽  
Buried Soils ◽  
West Antarctica ◽  
Glacial Ice ◽  
Last Glaciation ◽  
History Of ◽  
Climatic History ◽  
Transantarctic Mountains

Abstract. The Transantarctic Mountains (TAMs), a 3500 km long chain that subdivides East Antarctica from West Antarctica, are important for reconstructing the tectonic, glacial, and climatic history of Antarctica. With an ice-free area of 24 200 km2 (50% of the total in Antarctica), the TAMs contain an unusually high proportion of paleosols, including relict and buried soils. The unconsolidated paleosols range from late Quaternary to Miocene in age, the semi-consolidated paleosols are of early Miocene to Oligocene age, and the consolidated paleosols are of Paleozoic age. Paleosols on unconsolidated deposits are emphasized in this study. Examples are given from the McMurdo Dry Valleys (78° S) and two outlet glaciers in the central and southern TAMS, including the Hatherton–Darwin Glacier region (80° S) and the Beardmore Glacier region (85°30' S). Relict soils constitute 73% of all of the soils examined; 10% of the soils featured burials. About 26% of the soils examined are from the last glaciation (< 117 ka) and have not undergone any apparent change in climate. As an example, paleosols comprise 65% of a mapped portion of central Wright Valley. Paleosols in the TAMs feature recycled ventifacts and buried glacial ice in excess of 8 Ma in age, and volcanic ash of Pliocene to Miocene age has buried some soils. Relict soils are more strongly developed than nearby modern soils and often are dry-frozen and feature sand-wedge casts when ice-cemented permafrost is present. The preservation of paleosols in the TAMs can be attributed to cold-based glaciers that are able to override landscapes while causing minimal disturbance.

scholarly journals Paleosols in the transantarctic mountains: indicators of environmental change

2013 ◽  
Vol 5 (2) ◽  
pp. 1007-1029 ◽  
Author(s):  
J. G. Bockheim
Keyword(s):  
Volcanic Ash ◽  
Late Quaternary ◽  
Dry Valleys ◽  
Buried Soils ◽  
West Antarctica ◽  
Glacial Ice ◽  
Last Glaciation ◽  
History Of ◽  
Climatic History ◽  
Transantarctic Mountains

Abstract. The Transantarctic Mountains (TAMs), a 3500 km long chain that subdivides East Antarctica from West Antarctica, are important for reconstructing the tectonic, glacial, and climatic history of Antarctica. With an ice-free area of 24 200 km2 (50% of the total in Antarctica), the TAMs contain an unusually high proportion of paleosols, including relict and buried soils. The unconsolidated paleosols range from late Quaternary to Miocene in age, the semi-consolidated paleosols are of early Miocene to Oligocene age, and the consolidated paleosols are of Paleozoic age. Paleosols on unconsolidated deposits are emphasized in this study. Examples are given from the McMurdo Dry Valleys (78° S) and two outlet glaciers in the central and southern TAMS, including the Hatherton-Darwin Glacier region (80° S) and the Beardmore Glacier region (85° 30' S). Relict soils constitute 73% of all of the soils examined; 10% of the soils featured burials. About 26% of the soils examined are from the last glaciation (< 117 ka) and have not undergone any apparent change in climate. As an example, paleosols comprise 65% of a mapped portion of central Wright Valley. Paleosols in the TAMs feature recycled ventifacts and buried glacial ice in excess of 8 Ma in age; and volcanic ash of Pliocene to Miocene age has buried some soils. Relict soils are more strongly developed than nearby modern soils and often are dry-frozen and feature sand-wedge casts when ice-cemented permafrost was present. The preservation of paleosols in the TAMs can be attributed to cold-based glaciers that are able to override landscapes while causing minimal disturbance.

Late Quaternary Glacial History of George VI Sound Area, West Antarctica

1982 ◽  
Vol 18 (3) ◽  
pp. 243-267 ◽  
Author(s):  
Chalmers M. Clapperton ◽  
David E. Sugden
Keyword(s):  
Amino Acid ◽  
Late Quaternary ◽  
Ice Age ◽  
Dry Valleys ◽  
West Antarctica ◽  
Ice Shelf ◽  
Ice Caps ◽  
Climatic Control ◽  
Acid Ratio ◽  
History Of

AbstractDuring the last glacial maximum in West Antarctica separate ice caps developed on Alexander Island and on Palmer Land, became confluent in George VI Sound, and discharged northward from latitude 72° S. Radiocarbon (>32,000 yr) and amino acid (approximately 120,000 yr) age determinations on shell fragments (Hiatella solida) found in basal till suggest a Wisconsin age for the glaciation that incorporated them. The pattern of ice flow differed from that deduced for this area in the CLIMAP reconstruction. Following the maximum stage, there was a stadial event when outlet valley glaciers flowed from smaller ice caps into George VI Sound. More widespread recession permitted the George VI ice shelf to deposit Palmer Land erratics on eastern Alexander Island before isostatic recovery raised them to final elevations of about 82 m. The ice shelf may have been absent at about 6500 yr B.P., when large barnacles (Bathylasma corolliforme) were living in the sound. Small glaciers readvanced to form at least two terminal moraines before the ice shelf re-formed and incorporated the barnacle shells into its moraine on Alexander Island. The shells gave a 14C age (corrected for Antarctic conditions) of about 6500 yr B.P. and an amino acid ratio consistent with a Holocene age. Valley glaciers readvanced over the ice-shelf moraine before oscillations of both valley glaciers and the ice shelf led to the formation of the present sequence of contiguous ice-cored moraines, probably during the Little Ice Age. Such oscillations may represent a climatic control not yet observed in the dry valleys of Victoria Land, the only other part of Antarctica studied in detail for glacier fluctuations.

Late Quaternary vegetation and climatic history of eastern Nepal

2003 ◽  
Vol 24 (6) ◽  
pp. 837-843 ◽  
Author(s):  
Chuh Yonebayashi ◽  
Mutsuhiko Minaki
Keyword(s):  
Late Quaternary ◽  
History Of ◽  
Climatic History

scholarly journals Late-Quaternary Vegetational and Climatic History of the Yellowstone/Grand Teton Region

1988 ◽  
Vol 12 ◽  
pp. 189-192
Author(s):  
Cathy Barnosky
Keyword(s):  
Environmental History ◽  
Late Quaternary ◽  
Sediment Cores ◽  
Sediment Accumulation ◽  
Fire Frequency ◽  
Ice Age ◽  
Sediment Chemistry ◽  
History Of ◽  
Climatic History

The research underway has focused on two different aspects of the environmental history of the Yellowstone/Grand Teton region. One objective has been to examine the long-term vegetational and climatic history of Jackson Hole, the Pinyon Peak Highlands, and Yellowstone Park since the end of late Pinedale glaciation, about 14,000 years ago. Fossil pollen in sediment cores from lakes in the region is being analyzed to clarify the nature and composition of ice-age refugia, the rate and direction of plant migrations in the initial stages of reforestation, and the long-term stability of postglacial communities. Sedimentary charcoal also is being examined to reconstruct fire frequency during different climatic regions and different vegetation types in the past. This information is necessary to assess the sensitivity of plant communities to environmental change and to understand postglacial landscapes of the northern rocky Mountains. The second objective has been a multidisciplinary investigation of the relationship of climate to sedimentation rates in lakes and ponds in Yellowstone, undertaken with Drs. Wright, D.R. Engstrom and S.C. Fritz of the University of Minnesota. This facet of the research examines the relative importance of climate, fire, hillslope erosion induced by overgrazing, and nutrient enrichment in the last 150 years, as recorded in selected lakes in the northern range of Yellowstone. Populations of elk and bison are known to have fluctuated greatly during this interval, and slight climatic changes are suggested from other lines of research. In this study pollen, diatoms, charcoal, sediment chemistry, and sediment accumulation rates are analyzed in short cores from small lakes.

A Late Holocene desiccation of Lake Hoare and Lake Fryxell, McMurdo Dry Valleys, Antarctica

1998 ◽  
Vol 10 (3) ◽  
pp. 247-256 ◽  
Author(s):  
W.B. Lyons ◽  
S.W. Tyler ◽  
R.A. Wharton ◽  
D.M. McKnight ◽  
B.H. Vaughn
Keyword(s):  
Late Holocene ◽  
Mcmurdo Dry Valleys ◽  
Published Data ◽  
Dry Valleys ◽  
Humid Climate ◽  
The Past ◽  
Victoria Land ◽  
History Of ◽  
Lake Fryxell ◽  
Climatic History

Stable isotope data from waters of lakes in the McMurdo Dry Valleys (MDV) of southern Victoria Land, Antarctica are presented in order to establish the climatic history of this region over the past two millennia. New data from Lake Fryxell and Lake Hoare in Toylor Valley, along with previously published data from Lake Vanda, Wright Valley and Lake Bonney, Taylor Valley are used to infer the recent climatic history of MDV. Lakes Vanda, Fryxell and Bonney appear to have lost their ice covers and evaporated to small, hypersaline ponds by 1000 to ~1200 yr BP. Lake Hoare either desiccated or did not exist prior to 1200 yr BP. These data indicate a major lowering of lake level prior to ~1000 yr BP, followed by a warmer and/or more humid climate since then.

The late Quaternary history of lodgepole and jack pines

1985 ◽  
Vol 15 (5) ◽  
pp. 749-772 ◽  
Author(s):  
William B. Critchfield
Keyword(s):  
Late Quaternary ◽  
Jack Pine ◽  
The North ◽  
Last Glaciation ◽  
Variation Patterns ◽  
History Of ◽  
Quaternary History ◽  
Fossil Records ◽  
The Last Glacial Maximum ◽  
The Last Glacial

Lodgepole and jack pines (Pinuscontorta Dougl. ex. Loud. and Pinusbanksiana Lamb.), components of the North American boreal forest, have pioneering roles after major disturbances such as fire or glaciation. These species are closely related and hybridize in western Canada, but their fossil records and contemporary variation patterns suggest they had completely different late Quaternary histories. Several taxonomically recognized geographic races of lodgepole pine apparently survived the last glaciation without drastic modification, the northern races either persisting in far-northern refugia or migrating from the south. The uneven influence of jack pine on northern lodgepole populations implies repeated genetic contacts, but less marked introgression in the other direction could be of post-Pleistocene origin. Jack pine occupied its entire range after the last glacial maximum and lacks taxonomically recognized races. In the Great Lakes region, however, the presence of regionally distinct populations suggests the species had at least two Midwestern refugia. This hypothesis is contrary to the widely held view that jack pine occupied most or all of its range from a well-documented refugium in southeastern North America, but is supported by limited fossil evidence that pine persisted in the Midwest during the last glaciation.

Sign in / Sign up

Export Citation Format

Share Document