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| 塔里木盆地北部志留系碎屑锆石测年及其地质意义 | |
| 引用本文： | 邬光辉,张宝收,郭春利,王成林,高辉.塔里木盆地北部志留系碎屑锆石测年及其地质意义[J].大地构造与成矿学,2009,33(3). |
| 作者姓名： | 邬光辉 张宝收 郭春利 王成林 高辉 |
| 作者单位： | 1. 中国石油勘探开发研究院,北京,100083;塔里木油田勘探开发研究院,新疆,库尔勒,841000 2. 塔里木油田勘探开发研究院,新疆,库尔勒,841000 3. 郑州煤炭工业有限责任公司地质测量部,河南,郑州,450006 4. 中国石油勘探开发研究院,北京,100083 |
| 基金项目： | 国家重点基础研究发展计划(973)项目，中油勘探开发研究院中青年创新基金 |
| 摘 要： | 志留系是塔里木盆地第一套砂岩储层广泛分布的沉积盖层,其沉积来源与成因对志留纪构造演化及周边造山带的研究具有重要意义。塔里木盆地北部地区2个志留系代表性样品的碎屑锆石LA-ICP-MS U-Pb定年研究表明,志留系具有比较集中的三期物源年龄:中元古代早期1500～1600Ma、新元古代早期750～900Ma、奥陶纪450～500Ma。碎屑锆石定龄表明东部地区志留系物源主要来自阿尔金地区奥陶纪火成岩,而西部塔北地区志留系物源主要来自北部古隆起前寒武纪基底。前寒武纪锆石年龄揭示塔里木板块在新元古代时期与Rodinia超大陆具有相似的聚合与裂解演化史,塔里木北部地区在中元古代存在与Columbia超大陆裂解时间一致的构造-热事件。 |
| 关 键 词： | 塔里木 碎屑锆石 LA-ICP-MS年龄 物源 前寒武纪 超大陆 |
Detrital Zircon U-Pb Dating for the Silurian in Northern Tarim Basin and Its Significance |
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| WU Guanghui,ZHANG Baoshou,GUO Chunli,WANG Chenglin,GAO Hui.Detrital Zircon U-Pb Dating for the Silurian in Northern Tarim Basin and Its Significance[J].Geotectonica et Metallogenia,2009,33(3). | |
| Authors: | WU Guanghui ZHANG Baoshou GUO Chunli WANG Chenglin GAO Hui |
| Abstract: | The analysis of Silurian sedimentary provenances plays an important role in the evolution of the Silurian in the Tarim basin and the surrounding orogenic belts in which it is the first widespread sandstone cap rock in the Tarim basin. The U-Pb isotopic age of zircons from 2 clastic rocks in the northern Tarim basin was obtained in situ by LA-ICP-MS,it indicates that there are three groups sedimentary source ages for the Silurian:1500-1600 Ma of the early Mesoproterozoic,750-900 Ma of early Neoproterozoic,450-500 Ma of Ordovician. The zircon 207Pb/235U-206Pb/238U concordant ages were 447±65 Ma,760±6 Ma,1600±20 Ma respectively for the western and 474±50 Ma,885±1 Ma,1556±290 Ma for the eastern area in the northern Tarim basin. There are obvious different provenance regions and provenance ages for the Silurian between the eastern and western areas. Based on the data of detrital zircon ages and regional geology,the Ordovician igneous rocks in Altun Tagh were the main source of the Silurian in eastern area,and the Precambrian basement of the northern paleo-uplifts is the main provenance of the Silurian in western area. It is indicated that there is a large scale intraplate extension and magmatism in Nanhuan Period,and the Tarim plate had the same convergent and breakup history as the Rodinia supercontinent in the Neoproterozoic. It also demonstrated that the north Tarim continent maybe has the same tectonic event as the breakup of Columbia supercontinent,but not the same as the southern Tarim continent in the early Mesoproterozoic. This result has yielded a new intraplate age evidence to study the Precambrian evolution of the Tarim plate. |
| Keywords: | Tarim detrital zircon LA-ICP-MS age provenance Precambriam supercontinent |
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