Chronology and paleoenvironmental records of a drill core in the central Tengger Desert of China
Chronology and paleoenvironmental records of a drill core in the central Tengger Desert of China
复制标题
中国腾格里沙漠中部钻孔年代学和古环境记录
DOI：
10.1016/j.quascirev.2013.12.003
复制
发表时间：
2014-02-01
影响因子：
4
通讯作者：
Li, Baofeng
中科院分区：
文献类型：
--
作者：
Li, Zaijun;Sun, Donghuai;Li, Baofeng
亚洲内陆的沙漠化历史为亚洲干旱历史提供了最直接的证据，但由于缺乏露头，大多数亚洲沙漠的形成时代尚不清楚。腾格里沙漠是黄土高原的主要近缘沙漠之一，其沙尘排放和环境影响具有特殊的古气候意义。本文报道了腾格里沙漠中部第一个钻孔（WEDP 01）的岩相、古地磁年龄和古环境代用指标。古地磁测量表明，核心跨度从类似的3.55 Ma到现在，与电子自旋共振（ESR）测年结果一致。中部沙漠的地层自下而上由冲积河流沉积物、湖泊河流沉积物混合灰尘和风成沙组成。沉积分析表明，连续的风成砂开始于0.9Ma左右，标志着腾格里沙漠的初步形成;风成砂在与现代沙漠特征相似的地层中占主导地位，出现于0.68Ma左右，标志着腾格里沙漠的扩张。中更新世近源沙漠的形成以及近源沙漠与北太平洋沙尘堆积的同步增加，表明近源沙漠对北方乃至北方半球沙尘负荷的作用。我们的分析表明，青藏高原在中更新世的隆升可能发挥了主要作用的干燥事件和沙漠的形成，而全球冷却可能加强干旱环境的近端沙漠。(C)2013爱思唯尔有限公司版权所有。
The desertification history of inland Asia provides most direct evidence for Asian drying history, but the formation ages of the most Asian deserts are not clear due to the lack of outcrops. The Tengger Desert, one of the main proximal deserts of the Chinese Loess Plateau (CLP), is of special paleoclimatic significances for its dust emission and environmental affection. Here, we report lithofacies, paleomagnetic ages and paleoenvironmental proxy indexes of the first drill core (WEDP01) from the central Tengger Desert. Paleomagnetism measurements reveal that the core spans from similar to 3.55 Ma to present, consistent with the electron spin resonance (ESR) dating results. The strata of the central desert consist of alluvial fluvial deposits, lacustrine fluvial deposits mixed with dust, and eolian sand from bottom to top. Sedimentary analysis reveals that continuous eolian sand started by similar to 0.9 Ma, marking the initial formation of the Tengger Desert; and the domination of eolian sand in the strata with similar characters of the modern desert appeared by similar to 0.68 Ma, indicating expansion of the Tengger Desert. The proximal deserts formation and simultaneous increase of dust accumulation in the CLP and the North Pacific Ocean in mid-Pleistocene demonstrate the role of proximal deserts for the dust loading of Northern China and even Northern Hemisphere. Our analysis suggests the uplift of Tibetan Plateau in the mid-Pleistocene probably played the main role for this drying event and desert formation, while global cooling may strength the arid environment of the proximal deserts. (C) 2013 Elsevier Ltd. All rights reserved.