末次间冰期—末次冰期可可西里地区气候演化形式

发布时间：2018-12-11 00:25

【摘要】：选择青藏高原腹地可可西里地区为研究区,通过对湖泊沉积物色度、磁化率、总有机碳和粒度等分析,对可可西里地区末次间冰期以来的气候演变形式进行了恢复,其演化阶段大致可以与深海氧同位素进行对比。可可西里地区气候变化既表现出与全球气候变化一致的特点,也存在着独特的区域特征。末次间冰期气候波动可以和深海氧同位素相比,也可划分出5个亚段,但两者的波动形式存在差异,深海氧同位素指示5e最暖,而本区气候可能在5a暖湿配置最好;末次冰期气候环境整体较差,只有在间冰阶湖泊水体略有增大,总有机碳也呈小的峰值,色度和磁化率的峰值较高,对应于3c和3a的两个暖期,说明此时段较为温暖,但湿度较差。可能受到构造运动的影响湖泊水体缩小,水动力增大的缘故,相应的沉积条件较差,导致总有机碳含量较低。其他时段各指标均为低值显示气候较为寒冷,只出现一些小的峰值可能与Dansgaard-Oeschger旋回一致。直至1万年以来,各指标呈增大趋势,可能与全新世气候增暖湿有关。
[Abstract]:In this paper, the hinterland of the Qinghai-Xizang Plateau is selected as the study area. By analyzing the chromaticity, magnetic susceptibility, total organic carbon and particle size of the lake sediments, the climatic evolution forms since the last interglacial period in the Hoh Xili region are restored. Its evolution stage can be compared with deep sea oxygen isotopes. The climate change in Hohsili region is not only consistent with global climate change, but also has unique regional characteristics. The last interglacial climatic fluctuation can be compared with deep-sea oxygen isotopes and can also be divided into five subsections, but there are differences in their fluctuation forms. Deep-sea oxygen isotopes indicate that 5e is the warmest, and the climate in this area may be the best in 5 years. The climatic environment of the last glacial epoch was poor, only the lake water increased slightly in the interglacial terrace, the total organic carbon also showed a small peak value, the peak value of chrominance and magnetic susceptibility was higher, corresponding to the two warm periods of 3C and 3a, which indicated that the period was warmer. But the humidity is poor. As a result of the decrease of water body and the increase of hydrodynamic force, the deposition conditions may be poor, resulting in the low content of total organic carbon (TOC). In other periods, all the indicators are low, indicating the colder climate, and only a few small peaks may be consistent with the Dansgaard-Oeschger cycle. Up to 10,000 years, the indexes showed an increasing trend, which may be related to the warming and humidity of the Holocene climate.
【作者单位】：山西师范大学地理科学学院;兰州大学资源环境学院冰川与生态地理研究所;陕西师范大学旅游与环境学院;
【基金】：国家自然科学基金项目(40871057,41401226)
【分类号】：P532

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