کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4729412 | 1356527 | 2010 | 11 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Evidence for Late Ordovician glaciation of Al Kufrah Basin, Libya
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
پیش نمایش صفحه اول مقاله

چکیده انگلیسی
Fieldwork at the flanks of Al Kufrah Basin, Libya, reveals that Late Ordovician ice sheets were present in the eastern Sahara and that they extended northeastward toward Egypt. Evidence for grounded ice sheets is preserved at the both the southeastern (Jabal Azbah) and northern (Jabal az-Zalmah) basin margins. Characteristic soft-sediment deformation structures, including soft-sediment folds, small-scale faults and striated pavements indicate subglacial shearing and the formation of glacial erosion surfaces. These findings support the presence of a Late Ordovician ice margin in the eastern Sahara and add vital new constraints to reconstructions of the morphology of North African grounded ice sheets. Prior to our study, there existed two plausible models on ice sheet geometry. The first was that separate ice sheets - namely a north and west African ice sheet and an Arabian ice sheet - extended over this part of western North Gondwana. The second was that ice cover was continuous. The presence of a suite of subglacially-generated deformation structures adds considerable credence to the latter interpretation.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Journal of African Earth Sciences - Volume 58, Issue 2, September 2010, Pages 354-364
Journal: Journal of African Earth Sciences - Volume 58, Issue 2, September 2010, Pages 354-364
نویسندگان
Daniel Paul Le Heron, James Howard,