Surface exposure dating reveals MIS-3 glacial maximum in the Khangai Mountains of Mongolia
Surface exposure dating reveals MIS-3 glacial maximum in the Khangai Mountains of Mongolia
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DOI：
10.1016/j.yqres.2014.04.006
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发表时间：
2014-09
影响因子：
2.3
通讯作者：
H. Rother;F. Lehmkuhl;D. Fink;V. Nottebaum
中科院分区：
文献类型：
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作者：
H. Rother;F. Lehmkuhl;D. Fink;V. Nottebaum
本研究提出的结果，地貌制图和宇宙成因放射性核素测年（10 Be）的冰碛序列Otgon Tenger（3905米），在Khangai山脉（蒙古中部）的最高峰。我们的研究结果表明，冰川达到了最后的最大范围之间的40和35万年的海洋氧同位素阶段（MIS）3。在MIS-2期间（约23和17-16 ka）也发生了大的冰进展，但这些进展没有超过MIS-3期间达到的极限。结果表明，气候条件在MIS-3，其特点是一个凉爽潮湿的气候，比今天输入的冬季降水，产生了最有利的设置在研究区域的冰川作用。然而，冰川堆积也积极响应MIS-2的更冷和更干燥的条件，并再次在最后一次冰期-间冰期过渡时，降水量增加。从其他更新世冰川记录的背景下，从高亚洲，蒙古中部的冰川作用的模式，从中亚南部和东北西藏（即冰最大值在interstadial湿阶段）的记录，而蒙古记录的其他功能（即主要的冰扩张期间MIS-2日射最小值）更符合已知的西伯利亚和中亚西部的冰川响应。
This study presents results from geomorphological mapping and cosmogenic radionuclide dating (10Be) of moraine sequences at Otgon Tenger (3905 m), the highest peak in the Khangai Mountains (central Mongolia). Our findings indicate that glaciers reached their last maximum extent between 40 and 35 ka during Marine Oxygen Isotope Stage (MIS) 3. Large ice advances also occurred during MIS-2 (at ~ 23 and 17–16 ka), but these advances did not exceed the limits reached during MIS-3. The results indicate that climatic conditions during MIS-3, characterized by a cool-wet climate with a greater-than-today input from winter precipitation, generated the most favorable setting for glaciation in the study region. Yet, glacial accumulation also responded positively to the far colder and drier conditions of MIS-2, and again during the last glacial–interglacial transition when precipitation levels increased. Viewed in context of other Pleistocene glacial records from High Asia, the pattern of glaciation in central Mongolia shares some features with records from southern Central Asia and NE-Tibet (i.e. ice maxima during interstadial wet phases), while other features of the Mongolian record (i.e. major ice expansion during the MIS-2 insolation minimum) are more in tune with glacier responses known from Siberia and western Central Asia.