青海湖1F孔岩心的矿物学记录及其古环境意义  

MINERALOGICAL RECORDS OF HOLE 1F IN LAKE QINGHAI AND THEIR PALEOCLIMATIC IMPLICATIONS

作　　者：千琳勃[1,2] 宋友桂[1] 

机构地区：[1]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710075 [2]中国科学院研究生院,北京100049

出　　处：《海洋地质与第四纪地质》2010年第6期107-114,共8页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金项目(40972230,40772116);国家重点基础研究发展规划项目(2010CB833406)

摘　　要：对青海湖湖心18.5m长的1F孔样品进行了X射线衍射分析,重点分析了石英、文石、方解石和白云石随深度变化的特征。根据矿物组成和沉积相特征,该岩心以11.65和4.8m为界可以划分成明显不同的三阶段,反映了青海湖区气候总体上经历了冷干-较冷干-暖湿的变化历史,末次冰消期以来文石记录能与格陵兰GISP2冰心和董歌洞石笋记录进行良好的对比,反映了在某种程度上本区既受西风影响又受东亚季风影响。We applied X-Ray Diffraction Analysis to the mineralogy of the cores of Hole 1F, which was drilled in the center of northwest Qinghai Lake, and determined the content of quartz, aragonite, dolomite and calcite. Based on the characteristics of mineral assemblages, together with sedimentary facies, we divided the 18.5m long core into three distinctive segments at the depth of 11.65m and 4.8m indicating three climate stages. The results indicate that： （1） the mineralogy of the core is a record of paleoclimatic events in the Qinghai Lake. From the 18.5m long core, there were three paleoclimatic stages：Cold-dry period （18.5~11.65 m）, tempered cold-dry period （11.65~4.8 m）, and warm-humid period （4.7~0 m）, and the third period can be further divided into three periods： climatic oscillation period, the Holocene climatic optimum and cool-dry period. （2） the quartz content correlates well with the dry climate, high quartz content reflects a dry climate, while the low content represents a humid climate. （3） During the Last Glacial Period, there deposited little aragonite in the lake, but during the stage of Deglaciation, aragonite deposited steadily and reach the top value during Holocene. High aragonite content reflects a warm-humid climate, while low aragonite content represents a cold-dry climate, and can be reasonably correlated with δ18O record of stalagmite in Dongge cave. Quartz and aragonite assemblages may well represent Qinghai Lake’s paleoclimatic variation.

关 键 词：碳酸盐矿物 古气候 青海湖 

分 类 号：P532[天文地球—古生物学与地层学]