Proterozoic tectonism of the Arabian Shield
Proterozoic tectonism of the Arabian Shield
复制标题
阿拉伯地盾元古代构造作用
DOI：
10.1016/s0301-9268(02)00061-x
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发表时间：
2002
影响因子：
3.8
通讯作者：
M. Shanti
中科院分区：
文献类型：
--
作者：
A. Genna;P. Nehlig;E. L. Goff;C. Guerrot;M. Shanti
新的领域和分析工作，加上一个新的航磁图和地质，结构，地球化学和地质年代学的综合和重新评估，提供了一个新的角度解剖和地质历史的阿拉伯地盾。虽然在地盾东部发现了早元古代岩石，但地盾的主要地质演化仅限于900 - 530 Ma的时期，这一时期导致了几个构造地层学的形成、合并和最终的整合。前泛非构造（>690 Ma），由于较年轻的变形而难以破译，基本上是这些岩石的形成，合并和加积的结果。泛非构造运动（690-590 Ma）的特点是形成了Nabitah带和周边山脉，其间穿插着片麻岩圆顶。与这种构造作用同时期的各种沉积地层代表了前陆或陆内磨拉石盆地。泛非构造运动后，广泛的伸展（590-530马）带来了地壳变薄，产生双峰岩浆活动和显着的岩墙群;相关的火山岩形成Shammar组。与具有倾斜块体的被动边缘型构造相关的海侵标志着变薄的结束。这次海侵产生的台地相对应于Jibalah组的一部分。其他盆地是沿着转换断层形成的深陆拉分盆地。这一阿拉伯元古代地球动力学演化的最新观点为审查相关的成矿事件提供了一个框架，并将其置于新的年代学和构造历史中。
New field and analytical work, together with a new aeromagnetic map and a geologic, structural, geochemical, and geochronologic synthesis and reappraisal, offer a new view of the anatomy and geologic history of the Arabian Shield. Although Early Proterozoic rocks have been found in the eastern part of the Shield, the main geologic evolution of the Shield is limited to a period ranging from 900 to 530 Ma that led to the formation, amalgamation, and final cratonization of several tectonostratigraphic terranes. The pre-Panafrican structures (>690 Ma), which are difficult to decipher due to younger deformation, were essentially the result of the formation, amalgamation, and accretion of these terranes. The Panafrican tectonism (690–590 Ma) was marked by the formation of the Nabitah Belt and peripheral ranges punctuated by gneiss domes. Various sedimentary formations contemporaneous with this tectonism represent foreland or intracontinental molasse basins. After the Panafrican tectonism, widespread extension (590–530 Ma) brought about crustal thinning that generated bimodal magmatism and significant dike swarms; associated volcanics form the Shammar group. A marine transgression, associated with passive-margin-type structures with tilted blocks, marked the end of the thinning. The platform facies produced by this transgression correspond to part of the Jibalah Formation. Other basins formed as deep continental pull-apart basins along transform faults. This updated view of the Arabian Proterozoic geodynamic evolution provides a framework for reviewing the associated mineralizing events, and places them in a new chronology and structural history.