کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
5769895 1629196 2017 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Late Glacial/Early Holocene slope deposits on the Swiss Plateau: Genesis and palaeo-environment
ترجمه فارسی عنوان
رسوبات ناگهانی یخچال / زود هنگام هولوسن در فلات سوئیس: پیدایش و محیط زیست
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فرآیندهای سطح زمین
چکیده انگلیسی


- Optical Stimulated Luminescence of periglacial cover beds is possible.
- Periglacial cover beds indicate strong winter frost and increased climate seasonality during the Early Holocene.
- The period of Holocene soil evolution on the Swiss Plateau is limited to the last 7.500 years.

On the Swiss Plateau, glacial and glaciofluvial sediments deposited during MIS 2 are widespread. They are generally overlain by younger sediments of different origin, mainly related to periglacial and slope wash processes. Depending on their genesis and composition, 3 types of slope deposits can be distinguished, which are classified as units 1, 2a and 2b. Unit 1 is characterized by its wide spatial occurrence and a constant thickness of 40-60 cm, high silt contents, and a sharp lithological discontinuity to the lying sediments, generally forming the parent material for the Ah- and Al-horizons of the Luvisols. Unit 2 represents erosion rills, filled up with loess loam and some gravel (< 5%) due to slope wash. Locally, periglacial deformations led to cryoturbatic structures in these sediments, which is used to differentiate between unit 2a (no indications for periglacial activities) and unit 2b (with cryoturbations).Based on stratigraphic assumptions, the formation of unit 1 has been tentatively attributed to the Younger Dryas. Optical Stimulated Luminescence and radiocarbon dating of unit 2 indicate morphodynamic activity during the Early Holocene up to 7.5 ka, suggesting an open landscape. This scenario is in conflict with the established notion that reforestation in Middle Europe took place during the Bölling-Alleröd warm period. In order to explain this apparent contradiction for the Younger Dryas to Early Holocene environment, we suggest a continental climate with dry summers and drought stress on the vegetation, in combination with very cold winters and deep soil frost at the Pleistocene/Holocene transition, caused by the orbital precession maximum. After 7.5 ka, with the spread of oceanic woodland and reduced seasonal contrasts, the landscape stabilized and soils developed.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: CATENA - Volume 158, November 2017, Pages 102-112
نویسندگان
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