| Autor: |
Fotoohi, Samad, Negaresh, Hossein, Darvishi Khatooni, Javad, Bayat, Maqsoud |
| Předmět: |
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| Zdroj: |
Environmental Earth Sciences; Jan2022, Vol. 81 Issue 1, p1-17, 17p, 2 Color Photographs, 1 Diagram, 3 Charts, 3 Graphs, 2 Maps |
| Abstrakt: |
Lakes provide high-sensitivity and high-resolution documents and evidence, which are required for studying climatic changes and sedimentary environments at the global level. Furthermore, aeolian deposits in lacustrine environments, because of recording drought periods and dust storms, are valuable archives of paleoenvironmental conditions. In the present study, besides collecting the previous data, it was attempted to sample three intact sedimentary cores with the maximum depth of 7.3 m and total depth of above 20 m, from the sediments of the lakebed by auger. Sedimentary facies were separated based on their color, grain size; sedimentary composition, grain shape, and type of evaporate minerals. The existence of brown-colored coarse-grained pneumatic sand particles during the early to mid-Holocene period (8.2 ka BP) indicated the occurrence of intense storms in Sistan Basin. Sequence of the fine- and very fine-grained pneumatic sands at the depth of 2.5 m represented the presence of the winds similar to the current "120 day winds" in Sistan plain. Moreover, in this study, two major drought periods (8.2 and 4.5 ka BP) were identified in Holocene sediments of the lakebeds of Hamun-e-Helmand and Hamun-e-Sabari, which indicated drying and expansion of the aeolian sediments on Hamun's lakebed. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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