海洋地质与第四纪地质2018，Vol.38Issue(1)：178-186,9.DOI:10.16562/j.cnki.0256-1492.2018.01.018
山溪性河流锆石年代学对比及对东部海区物源示踪意义
The comparison of detrital zircon geochronology between mountainous rivers in Eastern China and its implications for marine sediment provenance
摘要
Abstract
The detrital zircon geochronology is commonly applied to trace the sediment provenance,reconstruct the paleogeography,and reveal the tectono-sedimentary evolution history.Although zircon is an extremly tiny mineral (10-5 ～ 10-4m),it may provide geological information of such a large spatial scale (＞1010 m2) as the India-Asia collision,the birth of the Yangtze River and the tecotono-sedimentary evolution of Taiwan Island.The aim of this study is to reveal the characteristics and controlling factors of the detrital zircon geochronology of mountainous rivers by comparing zircon U-Pb ages of river sands between two kinds of river basins drainning through different lithology (sedimentary rocks and igneous rocks) in southeastern China.In this contribution,we measured the detrital zircon U-Pb ages of the river sands from the Zhuoshui and Lanyang Rivers of Taiwan,and collected zircon age data of four small mountianous rivers in southeastern mainland from literatures.It is found that there is a huge discrepancy in the detrital zircon geochronology of small mountainous rivers in southeastern China.The zircon age populations of the Jiulong and Ou Rivers are very simple,with a dominant peak in late Mesozoic age.As the basin area becomes larger,the North and Min Rivers show more zircon age groups,including Mesozoic,Paleozoic and Precambrain peaks.In comparison,although the basin areas of Taiwanese mountainous rivers are extremly small ((1 ～3) × 103 km2),the zircon age distributions are very complex.Especially,the Zhuoshui River owns a high proportion of Precambrain zircons.In order to reveal the controlling factors of the detrital zircon geochronology,the zircon U-Pb age distributions of river sands in southeastern China are compared with the bedrock characteristics in related river basins.It shows that the detrital zircon geochronology of river sands in southeastern mainland corresponds well to regional tectono-igneous activities.By contrast,the detrital zircon geochronology of river sands in Taiwan is closely related to the tectono-sedimentary evolution of this lsland.In addition,based on the characteristics of the detrital zircon geochronology of river sands,the medium-and samllsized mountainous rivers in southeastern China can be divided into three end-members.The first is the small rivers along the southeastern coast,which have an intense Yanshanian age peak.The second is the medium-sized rivers in southeastern mainland with an obvious Caledonian age peak.As to the third,the western rivers in Taiwan own not only a high proportion of Precambrain zircons,but also obvious Jinningian and Lüliangian age peaks.To sum up,characterizing these end-members can provide important instructions for tracing the provenance of coarse sediments deposited in the Taiwan Strait and the inner shelf of the East China Sea during the last glacial period.关键词
碎屑锆石年代学/物源示踪/岩浆活动/沉积演化/台湾/东海陆架Key words
detrital zircon geochronology/sediment provenance/igneous activities/sedimentary evolution/Taiwan/East China Sea Shelf分类
天文与地球科学引用本文复制引用
邓凯,杨守业,黄湘通,徐娟..山溪性河流锆石年代学对比及对东部海区物源示踪意义[J].海洋地质与第四纪地质,2018,38(1):178-186,9.基金项目
科技基础性工作专项“典型中小入海河流河口动力沉积地貌与环境本底数据调查”(2013FY112200) （2013FY112200）
上海市优秀学科带头人计划(14XD1403600) （14XD1403600）
