| 扬子克拉通北缘神农架地区矿石山组Pb-Pb等时线年龄及其地质意义 |
| |
| 引用本文： | 卢山松,邱啸飞,谭娟娟,吕红,杨红梅,王志先,钟权.扬子克拉通北缘神农架地区矿石山组Pb-Pb等时线年龄及其地质意义[J].地球科学,2016,41(2):317-324. |
| |
| 作者姓名： | 卢山松 邱啸飞 谭娟娟 吕红 杨红梅 王志先 钟权 |
| |
| 作者单位： | 1.中国地质调查局武汉地质调查中心，湖北武汉 430205 |
| |
| 基金项目： | 中国地质调查局项目1212011121102中国地质调查局项目Nos.12120114005701国家自然科学基金青年基金No.41303026 |
| |
| 摘 要： | 扬子克拉通北缘神农架地区出露了大量中元古代碳酸盐岩地层，但已有的同位素年代学资料有限，故对神农架群矿石山组白云岩开展了全岩Pb-Pb等时线测年.研究结果表明，矿石山组白云岩206Pb/204Pb变化范围相对较大，为18.753~23.106，而207Pb/204Pb和208Pb/204Pb则变化范围相对较小，分别为15.606~16.046和37.793~38.599.八件白云岩样品206Pb/204Pb和207Pb/204Pb之间呈良好的线性关系，构成Pb-Pb等时线年龄为1632±75Ma(MSWD=8.7)，代表了矿石山组地层主体沉积时代，与已有的年代学结果可对应，表明Pb-Pb同位素体系可对古老的碳酸盐岩地层进行较为精确地定年.结合前人对于神农架群的年代学资料，确定神农架群的沉积时限应为1600~1100Ma的中元古代.
|
| 关 键 词： | 神农架群 矿石山组 Pb-Pb等时线 中元古代 碳酸盐岩 岩石学 |
| 收稿时间： | 2015-08-05 |
The Pb-Pb Isochron Age of the Kuangshishan Formation in Shennongjia Area on the Northern Margin of the Yangtze Craton and Its Geological Implications |
| |
| Abstract: | The Shennongjia Group, located on the northern margin of the Yangtze Craton, shows a series of well-preserved succession of the Mesoproterozoic carbonate strata. However, geochronological data collected from this area are limited. In this study, we report a Pb-Pb isochron age for the Kuangshishan Formation of the Shennongjia Group. The 206Pb/204Pb ratios of the dolostone of the Kuangshishan Formation show wide variations from 18.753 to 23.106. On the contrary, the 207Pb/204Pb ratios and the 208Pb/204Pb ratios have a limited range from 15.606 to 16.046 and 37.793 to 38.599, respectively. 8 dolostone samples data show an obvious linear relationship between 206Pb/204Pb and 207Pb/204Pb, yielding a Pb-Pb isochron age of 1632±75Ma (MSWD=8.7) which represent the depositional age for the Kuangshishan Formation. This age accords well with previous published data, indicating that a precise stratigraphic age of the ancient carbonate strata can be obtained through Pb-Pb dating technique. Combined with previous researches, we suggest that the age span of the Shennongjia Group is 1600 to 1100Ma of Mesoproterozoic. |
| |
| Keywords: | |
| 本文献已被 万方数据 等数据库收录！ |
| 点击此处可从《地球科学》浏览原始摘要信息 |
| 点击此处可从《地球科学》下载免费的PDF全文 |
