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| 西藏洞错全新世早中期盐湖沉积的古气候记录 | |
| 引用本文： | 魏乐军,郑绵平,蔡克勤,葛文胜.西藏洞错全新世早中期盐湖沉积的古气候记录[J].地学前缘,2002,9(1):129-135. |
| 作者姓名： | 魏乐军 郑绵平 蔡克勤 葛文胜 |
| 作者单位： | 1. 中国地质科学院,盐湖资源与环境开放研究实验室,北京,100037中国地质大学,北京,100083 2. 中国地质科学院,盐湖资源与环境开放研究实验室,北京,100037中国地质科学院,矿产资源研究所,北京,100037 3. 中国地质大学,北京,100083 |
| 基金项目： | 国家自然基金重点项目 ( 4 98330 10 ) |
| 摘 要： | 通过调查藏北高原腹地盐湖———洞错的Ⅰ阶地湖相化学沉积 ,发现硼砂及赋存 5层纯芒硝的完整沉积剖面。依据DZ0 1剖面的磁化率特征 ,结合韵律层的沉积学、盐类矿物学和14 C年代学 ,盐湖沉积物磁化率等恢复重建盐湖环境的替代性指标。指出洞错在全新世早、中期经历了潮湿温暖期(8470aBP ,可能至 10 5 0 0aBP± )→寒冷干旱期 (8470～ 8170aBP)→潮湿温暖期 (8170～ 75 90aBP)→气候频繁波动期 (75 90～ 740 0aBP ,寒冷大背景下三干三湿的气候演替 )→寒冷干旱期 (740 0～6 940aBP)→潮湿温和期 (6 940～ 6 6 2 0aBP)→寒冷干旱期 (6 6 2 0～ 6 410aBP)→温暖湿润时期(6 410aBP以后 ,可能至 330 0aBP)的演变过程。 |
| 关 键 词： | 西藏洞错 磁化率 全新世 古气候 盐湖 |
| 文章编号： | 1005-2321(2002)01-0129-07 |
| 修稿时间： | 2001年8月28日 |
EARLY-MIDDLE HOLOCENE PALAEOCLIMATE RECORD FROM SALINE LAKE SEDIMENTS IN TONTSO,TIBET |
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| WEI Le-jun ,ZHENG Mian-ping ,CAI Ke-qin ,GE Wen-sheng.EARLY-MIDDLE HOLOCENE PALAEOCLIMATE RECORD FROM SALINE LAKE SEDIMENTS IN TONTSO,TIBET[J].Earth Science Frontiers,2002,9(1):129-135. | |
| Authors: | WEI Le-jun ZHENG Mian-ping CAI Ke-qin GE Wen-sheng |
| Institution: | WEI Le-jun 1,2,ZHENG Mian-ping 1,3,CAI Ke-qin 2),GE Wen-sheng 2 |
| Abstract: | A saline lake—Tontso located in the center of Northern Tibetan Plateau was chosen as our study object. There is a very harsh nature environment in Tontso and is no human pollution there. Modern chemical sediments is depositing on the upper-bottom at present. During fieldwork, borax in mirabilite beds from Tontso first stage section was discovered for the first time, and sedimentary sections with whole five pure layers of mirabilite were also found. The discoveries are of important significance for appraisement of resources and ore-finding research in Tontso area, as well as for palaeoclimate and palaeoenvironment study. Based on the characteristics of magnetic susceptibility of the Tontso section DZ01, combined with the study on sedimentology, saline mineralogy and 14 C chronology, applied to comparative salinology of saline sedimentary environment, it is confirmed that mirabilite—as a kind of cold saline mineral—is a delicate and effective indicator; and that the saline sedimentary magnetic susceptibility is a reliable substitute for reconstruction of the palaeoclimate and palaeoenvironment. High discriminable analysis and study that based on the credible age scale sensitively rebuilt the Tontso’s palaeoclimate and palaeoenviroment according to saline chemical sediments. It is pointed out that Tontso frequently underwent a series of dry/wet and cold/warm climate changes during early-middle Holocene (>8470～6410aBP) as follows: before 8470aBP, probable to 10500aBP±: the stage of generally warm & wet; during 8470～8170aBP: the stage of frigid & arid (lasting 300a); during 8170～7590aBP: the stage of warm & wet (lasting 580a); during 7590～7400aBP: the stage of frequently fluctuating (lasting 190a), under frigid background, it went through a climate fluctuating of three arid and three wet alternation; during 7400～6940aBP: the stage of frigid & arid (lasting 460a); during 6940～6620aBP: the stage of warm & slightly wet (lasting 320a); during 6620～6410aBP: the stage of frigid & arid (lasting 210a); after 6410aBP: the stage of generally warm & wet (There is an interval on the top of sections from then on. The duration of the stage cannot be inferred). |
| Keywords: | Tibetan Tontso magnetic susceptibility Holocene palaeoclimate saline lake |
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