浙东南中生代晚期火山岩Nd同位素组成及其他地层学意义

浙东南中生代晚期火山岩Nd同位素组成及其他地层学意义

俞云文1，徐步台2，陈江峰3，董传万4

1. 浙江省区域地质调查大队，浙江萧山311201; 2. 浙江省地质矿产研究所，浙江杭州 310007; 3. 中国科技大学地球和空间科学系; 4. 浙江大学地球科学系

收稿日期:2001-03-20 修回日期:2001-03-20 出版日期:2001-03-20 发布日期:2001-03-20

Nd Isotopic Systematics of the Late Mesozoic Volcanic Rocks from Southeastern Zhejiang Province，China: Implications for Stratigraphic Study

YU Yun-wen, XU Bu-tai, CHEN Jiang-feng, DONG Chuan-wan

1. Zhejiang Regional Geological Survey Team, Xiaoshan，311201; 2. Zhejiang Institute of Geology and Mineral Resources, Hangzhou, 310007; 3. Department of Earth and Space Sciences, China University of Science and Technology, Hefei, 230026; 4. Department of Earth Sciences, Zhejiang University, Hangzhou, 3100327, China

Received:2001-03-20 Revised:2001-03-20 Online:2001-03-20 Published:2001-03-20

摘要/Abstract

摘要： 浙江东南部中生代晚期火山地层可划分为三个火山旋回，通过对不同层位火岩岩Nd同位素组成的研究，得出结果：第一至第三旋回火山岩（自下而上）εNd(t)值依次为－14．1－6．2，平均－9．9；－7．7－－6．4，平均－7．0及－7．5－＋0．1，平均－4．6。t2DM值依次为1．6－1．8Ga，平均1．7Ga；1．4－1．6Ga，平均1．5Ga及0．9－1．5Ga。由此可见，在不同的火山旋回之间具有明显的Nd同位素组成特征差异，它反映了该区中生代晚期火山活动随时间的推移，在构造环境和岩浆来源上所发生的有序变化，从而，Nd同位素示踪信息也就有可能作为火山地层划分和对比的重要依据之一。

Abstract: Late Mesozoic volcanic rocks in southeastern Zhejiang Province can be subdivided into three stratigraphic cycles. The εNd(t)values for these three cycles，from bottom to top，are -14.1 to –6.2, with an average of –10.0; -7.7 to –6.3，with an average of –7.0; and -7.5 to 0，with an average of –4.6，respectively. T2DM for the three cycles are 1.6 to 1.8， with than average of 1.72Ga; 1.4to 1.6，with an average of 1.48Ga; and 0.9 to l.5 with an average of 1.3lGa，respectively. Vo1canic rocks from different cycles show significant variation in Nd isotopic compositions, indicating that the tectonic environment of formation and the magma source of volcanic rocks varied with time. Therefore. Nd isotopic compositions of the volcanic rocks are very important in stratigraphic division and comparison

俞云文，徐步台，陈江峰，董传万. 浙东南中生代晚期火山岩Nd同位素组成及其他地层学意义[J]. J4.

YU Yun-wen, XU Bu-tai, CHEN Jiang-feng, DONG Chuan-wan. Nd Isotopic Systematics of the Late Mesozoic Volcanic Rocks from Southeastern Zhejiang Province，China: Implications for Stratigraphic Study[J]. J4.