Tectonic framework and crustal evolution of the Precambrian basement of the Tarim Block in NW China: New geochronological evidence from deep drilling samples
Tectonic framework and crustal evolution of the Precambrian basement of the Tarim Block in NW China: New geochronological evidence from deep drilling samples
复制标题
DOI：
10.1016/j.precamres.2013.06.001
复制
发表时间：
2013-09
影响因子：
3.8
通讯作者：
Zhiqin Xu;Bizhu He;Chuan-Lin Zhang;Jianxin Zhang;Zhaoyuan Wang;Zhihui Cai
中科院分区：
文献类型：
--
作者：
Zhiqin Xu;Bizhu He;Chuan-Lin Zhang;Jianxin Zhang;Zhaoyuan Wang;Zhihui Cai
根据塔里木盆地前寒武纪基底岩石学新观察和深钻岩心锆石U-Pb年代学资料，并与塔里木盆地造山带周边前寒武纪基底进行对比，重建了一个可能的统一塔里木地块。本文资料将塔里木地块900 Ma前的基底划分为塔北、塔南和塔中三部分。塔里木盆地北方、库尔勒-库鲁克塔格和敦煌地区的前寒武纪基底在塔北地区具有较好的成岩作用。2.7- 2.5Ga或更古老的陆核，经历了多期岩浆和变质事件。2.0- 1.8Ga，1.0- 0.8Ga和760-687 Ma。塔南地区包括塔里木盆地南部、东昆仑和西昆仑造山带的前寒武纪基底，具有2.4- 2.3Ga的陆核，经历了2.0- 1.75Ga和1.0- 0.8Ga的变质和岩浆事件。塔中地区包括塔里木盆地中部和阿尔金造山带的前寒武纪基底，940-890 Ma为岩浆弧系。经过1.0- 0.8Ga的塔里木南北陆块裂解、塔中洋形成、俯冲岩浆弧增生、塔南北陆块拼合等一系列地质作用，统一的塔里木陆块被拼合为Rodinia超大陆的一部分。新元古代中期岩浆活动分两期，分别为820-760 Ma和760-687 Ma。它们最有可能与Rodinia羽活动的两个阶段有关。中元古界晚期至震旦纪Rodinia的组装和裂解导致了塔里木地块典型的双层结构，即前南华纪基底和南华纪至震旦纪盖层序列。在此基础上，我们认为，由塔里木盆地前寒武纪基底及其周围造山带组成的统一塔里木地块，其规模应大于现今的塔里木盆地。
Based on new petrographic observations and zircon U–Pb geochronological data of the Precambrian basement from deep drilling cores in the Tarim basin and comparison with the Precambrian basements surrounding orogenic belts of the Tarim basin, we reconstruct a possible unified Tarim block. Data presented in this contribution lead to a three-fold subdivision of the pre-900 Ma basement of the Tarim block into the North Tarim terrane, the South Tarim terrane and the Central Tarim terrane. The North Tarim terrane containing Precambrian basements of the northern part of the Tarim basin, the Korla-Kuluketage and the Dunhuang area possesses a ca. 2.7–2.5 Ga or an even older continental nucleus and underwent multiple phases of magmatic and metamorphic events at ca. 2.0–1.8 Ga, 1.0–0.8 Ga and 760–687 Ma. The South Tarim terrane including Precambrian basements of the southern part of the Tarim basin, eastern Kunlun and western Kunlun orogenic belts, possesses a 2.4–2.3 Ga continental nucleus and underwent 2.0–1.75 Ga and 1.0–0.8 Ga metamorphic and magmatic events. The Central Tarim terrane encompassing Precambrian basement of the central part of the Tarim basin and the Altun orogenic belt, is characterized by magmatic arc system during 940–890 Ma. The unified Tarim Block was assembled as part of Rodinia supercontinent after series of geological processes, e.g. (1) breakup between the North and South Tarim terranes, (2) formation of the Central Tarim ocean, (3) subduction-related magmatic arc accretion, and (4) finally amalgamation of the North and South Tarim terranes during 1.0–0.8 Ga. There are two phases of the middle Neoproterozoic magmatic activities at 820–760 Ma and 760–687 Ma, respectively. They were most possibly related to the two phases of the Rodinia plume activities. The late Mesoproterozoic to Sinian assembly and breakup of the Rodinia led to the typical double-layered structure of the Tarim Block, i.e. the Pre-Nanhuaian basement and the Nanhuaian to Sinian cover sequence. Based on this study, we suggest that the unified Tarim Block, composed of Precambrian basement of Tarim basin and its surrounding orogenic belts, should be more large than the present Tarim basin.