南黄海北部B03孔沉积物的重矿物特征及物源指示意义  

Characteristics of Heavey Mineral in the B03 Core on the North of the Yellow Sea and Provenance Implication

作　　者：赵利[1] 赵广涛[1] 何雨旸[1] 徐翠玲[1] 祁奇[1] 龙晓军[1] 

机构地区：[1]中国海洋大学海洋地球科学学院,海底科学与探测技术教育部重点实验室,山东青岛266100

出　　处：《中国海洋大学学报（自然科学版）》2014年第9期72-81,共10页Periodical of Ocean University of China

基　　金：国家自然科学基金项目(41376053);中国海洋大学OUC_SRTP项目(20120423028)资助

摘　　要：本文对取自南黄海北部的B03孔岩芯(330cm)沉积物进行了粒度和重矿物特征分析,并运用电子探针技术,分析了其典型层位角闪石的矿物化学特征。研究表明,B03孔柱状样为均一连续的粉砂质沉积,重矿物含量较低(平均仅0.65%),主要为云母类和闪石类矿物,岩芯以85cm处为界分为上、下2个沉积层,其重矿物组合分别为普通角闪石-云母类矿物-绿帘石和云母类矿物-普通角闪石-绿帘石。角闪石的EPMA分析显示其种属主要为镁角闪石,其次为镁钙闪石、铁镁钙闪石及阳起石,成因以中酸性侵入岩与中高级变质岩为主,上下沉积层角闪石特征元素Mg/Fe2+比值分别为2.03、1.90。综合分析认为,岩芯的主要物源为黄河源物质及山东半岛陆架基岩剥蚀产物的混源,上下沉积层的矿物特征差异暗示了沉积物源发生了变化,其分界线可能代表了黄河1855年改道事件在山东半岛东部陆架的区域响应。Heavy mineral assemblage and chemical characteristics of single mineral have important implications for the source.Based on the study of grain-size and detrital minals of the B03 hole core,which was drilled from the mud depositional body in the north of the Yellow Sea,analyzed the chemical characteristics of the typical mineral hornblende layers using electron microprobe techniques the authors.Tests showed it is homogeneous continuous silt deposition.The detrital minerals on 63-125μm revealed the heavy is very low,the average is only 0.65%,mainly including micas and shade stone minerals.The core can be divided into upper and lower sediment layer bounded at 85 cm,and their heavy mineral assemblage are hornblende-mica minerals-epidote and mica minerals-hornblende-epidote.Chemical analysis of amphibole showed that magnesiohornblende dominated,followed by ferrotschermakite,tschermakite and actinolite,and its Causes mainly belong to neutralize acidic intrusive rocks and senior metamorphic.Characteristic elements Mg/Fe2＋of amphibole in the upper layer is 2.03,while the lower layer is 1.90.Comprehensive analysis indicated that the major source of core are the modern Yellow River substance and the erosion of Shandong Peninsula shelf,the seabed bedrock,The differences of the upper and lower layers imply a change in sediment source.The dividing line between the upper and lower sedimentary layers represented the regional response in the eastern shelf of the Shandong Peninsula of Yellow River diversion events in1855.

关 键 词：泥质沉积 重矿物 角闪石 矿物化学 物源 环境 

分 类 号：P574.2[天文地球—矿物学]