长江水下三角洲沉积物的重矿物分布及组合  

HEAVY MINERAL CHARACTERISTICS OF SURFACE SEDIMENTS IN THE SUBAQUEOUS YANGTZE RIVER DELTA

作　　者：王昆山[1] 王国庆[1] 蔡善武 窦衍光[1] 石学法[1] 程振波[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国家海洋局第一海洋研究所,青岛266061 [2]深圳博伦职业技术学校,深圳518052

出　　处：《海洋地质与第四纪地质》2007年第1期7-12,共6页Marine Geology & Quaternary Geology

基　　金："908"专项研究专题(908-02-02-05);国家海洋局青年基金项目(2004302);青岛市科技将才专项计划项目(05-2-JC-79)

摘　　要：对2004年取自长江水下三角洲南部区域的145个表层样品进行了重矿物研究。结果表明,本区重矿物可划分为4个矿物组合区,即三角洲前缘南部矿物区(Ⅰ区)、三角洲前缘北部矿物区(Ⅱ区)、前三角洲主体矿物区(Ⅲ区)和前三角洲南部矿物区(Ⅳ区),它们代表了不同的沉积动力、沉积环境和风化作用条件;长江水下三角洲重矿物以普通角闪石-绿帘石为优势矿物组合,以低级变质来源的绢云母、白云母为特征矿物,局部富含普通辉石和氧化铁矿物;粉砂质砂和砂质粉砂中的重矿物组成比较稳定,基本可以代表长江物源。Heavy mineral characteristics of 145 surface sediment samples collected from the subaqueous Yangtze River delta were analyzed in detail. The analysis results suggested four mineral provinces in the study area. They were south part of delta front （area Ⅰ）, north part of delta front （area Ⅱ）, delta front （area Ⅲ） and south part of front delta （area Ⅳ）, each of which indicated unique sedimentary process, sedimentary environment, and weathering condition. In general, heavy minerals of the Yangtze River delta were characterized by relatively high contents of muscovite and sericite derived from metamorphic rock, and were dominated by common hornblende and epidote assembIage. At some places in the study area, au- gite and Fe-oxide mineral were found with low contents. According to present research, heavy minerals compositions of silty sand and sandy silt were relatively steady, indicating that heavy minerals of these two sediment types could imply sediment from the subaqueous Yangtze River delta when we do sediment source researches on the continent shelf of the East China Sea.

关 键 词：重矿物 矿物组合 物源 长江水下三角洲 

分 类 号：P736.21[天文地球—海洋地质]