东海DGKS9617岩心重矿物及自生黄铁矿记录  

RECORDS OF HEAVY MINERAL AND AUTHIGENOUS PYRITE IN CORE DGKS9617 FROM THE EAST CHINA SEA

作　　者：王昆山[1] 石学法[1] 李珍[1] 姜晓黎[1] 

机构地区：[1]海洋沉积与环境地质国家海洋局重点实验室,青岛266061

出　　处：《海洋地质与第四纪地质》2005年第4期41-45,共5页Marine Geology & Quaternary Geology

基　　金：国家自然科学基金重点项目(40431002);国家海洋局青年基金项目(2004302)

摘　　要：对东海DGKS9617岩心重矿物进行了详细研究.结果表明闪石类、帘石类、片状矿物、自生黄铁矿和金属矿物为优势重矿物.根据重矿物的稳定性,将该岩心的重矿物划分为4种组合类型,并在极稳定矿物组合、自生黄铁矿和榍石含量的时间序列分析基础上,将岩心自下而上划分为Ⅰ、Ⅱ、Ⅲ、Ⅳ共4个重矿物韵律层,各韵律层的优势矿物和特征矿物存在着明显的差异.根据矿物韵律曲线的变化与孢粉组合及竺可桢温度曲线的对比可推断出Ⅰ、Ⅱ、Ⅲ和Ⅳ层的底部年龄分别为6 000、5 000、2 800和1 300 aBP左右,各韵律层平均沉积速率分别为0.1、0.11、0.27和0.08 cm/a.自生黄铁矿含量变化指示出在2 900～1 800 aBP和1 300～850 aBP存在两个快速沉积期,其平均沉积速率分别约为0.14和0.13 cm/a,反映了当时河流物质输入量增大,为温暖湿润的气候期.Heavy minerals were analyzed in core DGKS9617 from the East China Sea. The result showed that dominant minerals were amphibole group, epidote group, schistose minerals, authigenous pyrite and metallic minerals. According to stability of these heavy minerals,there were four kinds of mineral assemblages. Based on time series analysis of extremely stable mineral assemblage, authigenous pyrite and sphene, the core can be classified into four rhythmic layers of heavy minerals, namely Ⅰ、Ⅱ、ⅢandⅣ, which have different dominant/diagnostic heavy minerals. The bottom boundaries of the four heavy mineral layers were dated to be at 6 000, 5 000, 2 800 and 1 300 aBP in ascending order by palynology assemblages and Zhu＇s climate fluctuation curve. Therefore, mean sedimentation rates of the four rhythmic layers were subsequently calculated to be 0. 1, 0. 11, 0.27 and 0.08 cm/a respectively. Furthermore, distinct variation of authigenous pyrite revealed that there were two periods of high sedimentation rate during 2 900 -1 800 aBP and 1 300-850 aBP, of which mean sedimentation rates were 0.14 and 0. 13 cm/a respectively. These two periods had warm and humid climate together with high terrestrial input.

关 键 词：重矿物 时间序列 沉积速率 东海 

分 类 号：P736.3[天文地球—海洋地质]