| 上扬子西南缘早三叠世嘉陵江组物源分析和构造环境:沉积学、重矿物电子探针和U- Pb年龄的限定 |
| |
| 引用本文： | 张英利,贾晓彤,王宗起,王坤明,陈木银.上扬子西南缘早三叠世嘉陵江组物源分析和构造环境:沉积学、重矿物电子探针和U- Pb年龄的限定[J].地质学报,2019,93(12):3197-3222. |
| |
| 作者姓名： | 张英利 贾晓彤 王宗起 王坤明 陈木银 |
| |
| 作者单位： | 中国地质科学院矿产资源研究所自然资源部成矿作用与资源评价重点实验室,北京,100037;浙江省工程地震研究所,杭州,310013;中国石油集团测井有限公司长庆事业部,西安,710201 |
| |
| 基金项目： | 本文为国家自然科学基金项目（编号 41302080，41602061）和中国地质科学院基本科研业务费项目（编号 K1613，JYYWF201814）资助成果。 |
| |
| 摘 要： | 上扬子西南缘地区广泛分布峨眉山玄武岩,受其影响在中带金阳和外带荥经地区嘉陵江组发育滨岸和潮坪环境沉积物。本文在交错层理恢复的物源方向基础上,根据重矿物组成、重矿物电子探针和碎屑锆石测年结果,综合分析不同区域嘉陵江组物源区,进而探讨嘉陵江组形成的构造环境。嘉陵江组砂岩碎屑重矿物锆石、磷灰石、铬尖晶石等指示物源主要来自于岩浆岩,且自中带至外带基性岩浆岩所占比重逐渐减少。电气石电子探针分析显示,二者物源主要来自于贫锂花岗岩和变质砂岩、板岩。铬尖晶石显示,金阳地区物源来自峨眉山玄武岩和洋岛岩浆岩类岩石,荥经物源主要来自洋岛岩浆岩类岩石,个别为峨眉山玄武岩。碎屑锆石表明,嘉陵江组物源主要来自于新元古代岩浆岩和晚二叠世峨眉山玄武岩,前者经历再搬运。综合物源分析表明,嘉陵江组物源主要来自康滇古陆,岩石类型主要为峨眉山玄武岩和砂岩等。沉积序列和物源分析表明,嘉陵江组反映了沉积物蚀顶过程。结合地震资料、大火成岩省的分析成果表明,嘉陵江组形成于火山型裂谷边缘。
|
| 关 键 词： | 嘉陵江组 碎屑重矿物 电子探针分析 碎屑锆石年代学 构造环境 |
| 收稿时间： | 2018/8/28 0:00:00 |
| 修稿时间： | 2018/11/14 0:00:00 |
Provenance analysis and tectonic setting of Early Triassic Jialingjiang Formation in the southwestern Upper Yangtze area: evidence from sedimentology,heavy mineral electron probe microanalysis and U- Pb dating |
| |
| ZHANG Yingli,JIA Xiaotong,WANG Zongqi,WANG Kunming and CHEN Muyin.Provenance analysis and tectonic setting of Early Triassic Jialingjiang Formation in the southwestern Upper Yangtze area: evidence from sedimentology,heavy mineral electron probe microanalysis and U- Pb dating[J].Acta Geologica Sinica,2019,93(12):3197-3222. |
| |
| Authors: | ZHANG Yingli JIA Xiaotong WANG Zongqi WANG Kunming and CHEN Muyin |
| |
| Abstract: | The Emeishan basalts are widely distributed in the southwestern margin of the Upper Yangtze area. Under the circumstances, coastal and tidal flat sediments of Jialingjiang Formation were deposited in intermediate zone of Jinyang and outer zone of Yingjing. Based on the source direction restored by cross bedding, the composition of heavy minerals, electron probe microanalysis (EPMA) and detrital zircon geochronology suggest the provenance area, further discussing the tectonic setting of Jialingjiang Formation. Detrital heavy mineral assembalges, such as zircon, apatite and chromian spinel, are mainly derived from magmatic rocks. Some of them are from basic magmatic rocks. The proportion of basic magmatic rocks from the intermediate zone to the outer zone gradually decreases. The tourmaline EPMA results show that the source rocks are mainly derived from Li- poor granitoids and their associated pegmatites and aplites, metapelites and metapsammites. The analysis of chromian spinel electron probe suggests that the source rocks in Jinyang area were from Emeishan basalts and ocean island basalts, while the provenance in Yingjing mainly came from ocean island basalts and a few from Emeishan basalt. Detrital zircon geochronology indicates that the provenance mainly came from Neoproterozoic magmatic rocks and Late Permian Emeishan basalt, which the former experienced transportation. The comprehensive analysis shows that the source of the Jialingjiang Formation is mainly from the Kangdian Oldland, and the main rock types are Emeishan basalt and sandstone. The sedimentary successions and provenance analysis both indicate that the Jialingjiang Formation reflects the process of sediment proof- erosion. Combined with seismic data and large igneous province results, Jialingjiang Formation formed in volcanic rifted margin. |
| |
| Keywords: | Jialingjiang Formation detrital heavy mineral electron probe microanalysis detrital zircon geochronology tectonic setting |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《地质学报》浏览原始摘要信息 |
| 点击此处可从《地质学报》下载免费的PDF全文 |
|
