کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4688792 | 1349874 | 2007 | 17 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Glaciation, erosion, and landscape evolution of Iceland
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
فرآیندهای سطح زمین
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چکیده انگلیسی
Stratigraphic and sedimentological studies indicate that Iceland has experienced over 20 glaciations during the last 4-5 Myr, in reasonable agreement with the number of glaciations reconstructed from the â18O record in deep-sea sediment. The pattern of glacial erosion was to a large part controlled by constructive volcanic processes resulting in increased topographic relief after 2.5 Myr. Between 2.5 and 0.5 Ma valleys up to 400 m deep were excavated into the Tertiary basalts of eastern and south Iceland with an average erosion rate of 10-20 cm kaâ1. During the last 0.5 million years rates of erosion increased to 50-175 cm kaâ1, with an additional 200 to over 1000 m of valley excavation. Previous estimates of the rate of landscape erosion during the Holocene vary widely, from 5 to 70,000 cm kaâ1. We present new studies that define the rates of landscape denudation during the major part of the Holocene (the last 10,200 years): one based on the Iceland shelf sediment record, the other from the sediment record in the glacier-fed lake, HvÃtárvatn. Both studies indicate average Holocene erosion rates of about 5 cm kaâ1 similar to our erosion rate estimate for 4-5 Ma old strata that has not been subjected to regional glaciation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of Geodynamics - Volume 43, Issue 1, January 2007, Pages 170-186
Journal: Journal of Geodynamics - Volume 43, Issue 1, January 2007, Pages 170-186
نویسندگان
Áslaug Geirsdóttir, Gifford H. Miller, John T. Andrews,