毛乌素沙漠东南缘DGS1层段CaCO_3记录的全新世气候变化  

Holocene climate changes recorded by CaCO_3 in the DGS1 segment in the southeast of the Mu Us Desert,China

作　　者：王丰年[1] 李保生[2,3] 牛东风[2] 温小浩[2] 李志文[4] 司月君[5] 郭亿华[6] 杨志英[1] 刘恩波[1] 

机构地区：[1]惠州学院旅游系,惠州516007 [2]华南师范大学地理科学学院,广州510631 [3]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,西安710061 [4]东华理工大学地球科学学院,南昌330013 [5]广西师范学院规划与地理科学学院,南宁530001 [6]广州地理研究所,广州510070

出　　处：《地球环境学报》2015年第3期145-153,共9页Journal of Earth Environment

基　　金：国家重点基础研究发展计划(2013CB955903);惠州学院博士科研启动项目(C_513.0203)

摘　　要：毛乌素沙漠东南缘萨拉乌苏河流域滴哨沟湾剖面DGS1层段主要由沙丘砂、湖沼相和次生黄土组成。根据测年结果，该层段为全新世风沙沉积序列。通过对该层段CaCO3的分析，发现CaCO3含量在沙丘砂、湖沼相和次生黄土依次变化于0．35％～2．74％（平均值1．03％）、0．13％～60．31％（平均值22．16％）和8．64％～12．83％（平均值9．21％），并与DGS1层段粒度Mz（平均粒径）呈显著相关（相关系数0．68）。研究表明，毛乌素沙漠冬季风盛行时期沙丘砂堆积，CaCO3发生迁移；夏季风盛行时期湖沼相发育，CaCO3相对聚集。据此，我们认为CaCO3含量变化揭示了毛乌素沙漠在全新世以来经历了多次冬夏季风交互演替的气候变化过程．全新世气候波动主要可分为4个阶段：全新世早期回暖期、全新世鼎盛期、暖冷过渡期和冷千气候不稳定期。Located in the Salawusu River Valley on the southeast edge of the Mu Us Desert, the DGS 1 segment of the Dishaogouwan section consists of dune sands, lacustrine facies and secondary loess. Based on the age determination, the DGS 1 segment belongs to the aeolian sedimentary sequence of the Holocene. By CaCO3 analysis, we found that CaCO3 contents in the DGS1 segment range from 0.35% to 2.74% （average 1.03%） in the dune sands, 0.13% to 60.31% （average 22.16%） in the lacustrine facies and 8.64% to 12.83% （average 9.21%） in the secondary loess, respectively; and the CaCO3contents have a significant correlation with Mz （coefficient 0.68 ）. This study shows that the dune sands accumulate and CaCO3 greatly moves away when the winter monsoon prevails; whereas, the lacustrine facies develop and CaCO3 largely gathers when the summer monsoon strengthens. Therefore, we suggest that the changes of CaCO3 content in the DGS 1 segment reveal multi-alternation between the East Asian winter and summer monsoons in the Mu Us Desert during the Holocene and the climate mainly experiences 4 periods within this area： Early warming period, Megathermal period, Cooling transitional period and cold-dry instable period.

关 键 词：毛乌素沙漠 DGS1 CACO3 气候变化 全新世 

分 类 号：P532[天文地球—古生物学与地层学]