| 摘要: |
| 为探讨柴达木盆地晚更新世的环境变迁，同时为青藏高原隆升对气候变化的影响提供基础资料，对柴达木盆地昆特依地区ZK1404钻孔沉积物中的正构烷烃分布特征以及ASM14C测年数据进行了分析。结果显示，昆特依地区晚更新世沉积物的正构烷烃总体上呈现以高碳数为主的分布特征，多数样品以nC27、nC29为主峰，部分以nC31为主峰，呈现出显著的奇碳优势。少数样品中低于nC21的短链正构烷烃相对丰度较高，主要以nC17、nC20为主峰碳数，无明显的奇偶优势。根据正构烷烃分布特征、AMS14C测年数据、区域地质调查资料及沉积环境判断，柴达木盆地昆特依地区晚更新世（33600~26370a B.P.）气候环境以温凉干旱与温凉干旱偏湿交替出现为特征，与现代大陆性干旱荒漠气候截然不同。 |
| 关键词: 正构烷烃 晚更新世 环境变迁 柴达木盆地 |
| DOI： |
| 附件 |
| 投稿时间：2019-03-05修订日期：2019-04-12 |
| 基金项目:青海省冷湖行委昆特依地区四幅1：5万区域地质调查项目（No.12120113033029） |
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| The n-alkane distribution and palaeoenvironmental changes during the late Pleistocene in the Kunteyi area, Qaidam Basin, Qinghai |
| XIANG Wei1, XIANG Shuyuan2, LI Weibo2,3, ZENG Xianchun1 |
(1. School of Environmental Studies, China University of Geosciences, Wuhan 430074, Hubei, China;
2. School of Earth Sciences, China University of Geosciences, Wuhan 430074, Hubei, China;
3. China Railway Construction Heavy Industry Corporation Limited, Changsha 410100, Hunan, China) |
| Abstract: |
| In order to explore the palaeoenvironmental changes during the late Pleistocene in the Qaidam Basin, Qinghai and provide the basic data for the study of the effects of the Qinghai-Xizang Plateau uplift on the palaeoclimatic changes, the present paper gives a detailed description of the n-alkane distribution and ASM 14C dating for the sediments from the ZK-1404 well in the Kunteyi area, Qaidam Basin. The n-alkanes in most of the samples from the ZK-1404 well are characterized by high carbon numbers such as nC27, nC29 and nC31, suggesting the odd-carbon advantage. Several samples contain higher relative abundance short-chain n-alkanes (carbon numbers less than nC21), with nC17 and nC20 as the main peaks and without the odd-carbon advantage. Judged from the n-alkane distribution, ASM 14C dating, regional geology and palaeoenvironmental studies, the late Pleistocene (33600a to 26370a B.P.) palaeoclimatic conditions in the Kunteyi area, Qaidam Basin display the alterative changes of warm, cool and dry palaeoclimatic conditions, and warm, cool, dry and humid palaeoclimatic conditions, which are distinctly different from the modern continental arid desert climatic conditions. |
| Key words: n-alkane late Pleistocene palaeoenvironmental change Qaidam Basin |
