干旱区生态环境知识资源中心(Arid): 青藏高原东北缘尖扎盆地碳酸盐含量及其古环境意义

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	青藏高原东北缘尖扎盆地碳酸盐含量及其古环境意义
其他题名	CARBONATE CONTENT OF JIANZHA BASIN IN NORTHEASTERN MARGIN OF THE TIBETAN PLATEAU AND PALEOCLIMATIC SIGNIFICANCE
	席建建 1; 符超峰 2; 孟媛媛 1; 王祎 1
来源期刊	第四纪研究
ISSN	1001-7410
出版年	2018
卷号	38 期号:1 页码:107-117
中文摘要	尖扎盆地地处青藏高原的东北缘,位于青藏高原寒旱区、西北内陆干旱区和东部季风区的交汇地带,同时又处在东亚季风和西风环流的汇聚地带,属于气候极度敏感区域,盆地内部沉积了巨厚且连续的新生代沉积物。青海省尖扎县城西面的加让剖面主要以风成红粘土沉积为主体,但发生过多次沉积微相变化,夹杂有短暂的湖相及河流相沉积。红粘土中主要的碳酸盐矿物由方解石和白云石组成,通过对红粘土中方解石和白云石含量的实验测定,将方解石含量变化曲线和磁化率变化曲线进行对比分析,可将厚度为361 m的加让剖面经历了11.8~5.8 Ma沉积序列划分为以下4个气候阶段:11.8~9.8 Ma气候干冷期;9.80~8.57 Ma气候温暖湿润期;8.57~6.15 Ma气候温暖湿润期及6.15~5.80 Ma气候干冷期。在约8.57 Ma沉积物方解石含量和磁化率急剧变化,由于青藏高原的隆升,夏季风明显加强,约7.2 Ma之后,夏季风的变化受高原隆升、全球变冷和北极冰盖扩张综合影响。白云石含量在10~8 Ma变化显著增加,可能是由于这一时期青藏高原快速隆升,盆地周缘山脉风化剥蚀加快,近源物质增多所致。
英文摘要	Jianzha Basin is located in the northeastern Tibetan Plateau and situated in a climatically sensitive area-at the transition zone between the monsoon region to the east and the arid region to the west; its location, together with its thick, continuous sequence of Cenozoic sediments, makes it well be suited to monitoring changes in Late Cenozoic climate. Jiarang section is located in the left bank of the Jiarang river, near the Jiarang village of Jianzha County, Qinghai Province, and its geographical coordinates are 35°57’43.1"N,101°58’24.1"E,2200 m a.s.l. Based on the field observation and the study of sedimentary facies, the 361-m-thick sediments sequences of the Jiarang section mainly consist of clastic material of fluviolacustrine and eolian origin,with loess-like silt or clay comprising about two-thirds of the entire section. The samples of this experiment was sampled at 20 cm intervals, and a total of 1781 samples were collected. The magnetostratigraphic results show that the sediments have recorded a continuous geomagnetic polarity sequence from C5r.3r to C3r,spanning the interval from 11.8~5.8 Ma in the Late Miocene. By the experiments analysis of the carbonate minerals in sedimentary section, the content of calcite and the low frequency magnetic susceptibility change were analyzed to reveal the paleoclimatic information from the deposits during 11.8~5.8 Ma, which the paleoclimate change can be divided into four stages. Stage I: 11.8 ~ 9.8 Ma, dry and cold climate; Stage Ⅱ:9.80~8.57 Ma, warm and humid climate; Stage Ⅲ: 8.57~6.15 Ma, warm and humid climate and Stage IV: 6.15 ~ 5.80 Ma, dry and cold climate. The content of calcite and the magnetic susceptibility change dramatically before ca. 8.57 Ma reflect intensified precipitation which resulted from the growth of the NETP. From ca. 8.57 Ma to ca. 7.2 Ma, the East Asian summer monsoon was impacted by global cooling and ice build-up in the Northern Hemisphere in addition to the uplift of the Tibetan Plateau in the Late Miocene. From ca.10 Ma to ca. 8 Ma, the content of dolomite increases significantly, which probably caused by the rapid uplifting and deforming of the Tibetan Plateau in this stage.
中文关键词	青藏高原东北缘 ; 碳酸盐 ; 方解石 ; 白云石 ; 古环境
英文关键词	northeastern margin of Tibetan Plateau carbonate calcite dolomite paleoenvironment
语种	中文
国家	中国
收录类别	CSCD
WOS类目	GEOLOGY
WOS研究方向	Geology
CSCD记录号	CSCD:6157271
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/237483
作者单位	1.长安大学,地球科学与资源学院, 西安, 陕西 710054, 中国; 2.长安大学,地球科学与资源学院;;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;;西安, 陕西;;陕西 710054;;710061, 中国
推荐引用方式 GB/T 7714	席建建,符超峰,孟媛媛,等. 青藏高原东北缘尖扎盆地碳酸盐含量及其古环境意义[J],2018,38(1):107-117.
APA	席建建,符超峰,孟媛媛,&王祎.(2018).青藏高原东北缘尖扎盆地碳酸盐含量及其古环境意义.第四纪研究,38(1),107-117.
MLA	席建建,et al."青藏高原东北缘尖扎盆地碳酸盐含量及其古环境意义".第四纪研究 38.1(2018):107-117.