Archean Sedimentation Adjacent To An Orogenic Belt-Examples From Zimbabwe With Implications For Archean Tectonics

南部非洲的林波波省是一个高级变质带，代表了大陆-大陆碰撞带的出土根源。北部为津巴布韦省的花岗岩-绿岩地体，南部为卡普瓦省，两侧是林波波省。在Kaapvaal克拉通上，Witwater srand超群被解释为前陆-盆地充填，代表了林波波造山中碰撞事件的沉积响应。毗邻林波波省北部边缘地带的津巴布韦克拉通不存在与威特沃特斯兰德超群具有类似横向范围、厚度和岩性的沉积序列。相反，绿岩带中存在五个不同时代的局部和岩性截然不同的地层序列。这些层序中至少有四个发育在较低和较高的绿岩中，其年龄与威特沃特斯兰德超级群相当。津巴布韦没有与之对应的威特沃特斯兰德盆地，这对南部非洲太古宙的具体演化和太古代构造和沉积模式提出了几个重要问题：1)3.0-2.7Ga津巴布韦盆地中的两个盆地的详细特征是什么，包括源区组成、源区时代、源区位置、沉积物扩散模式、沉积环境、盆地配置、盆地演化和构造背景？2)津巴布韦沉积盆地与林波波造山作用的成因关系是什么？3)林波波造山作用是比利牛型还是喜马拉雅型？将对其中两个地层序列采用多学科方法，包括详细的野外测绘、构造分析、沉积学-地层学分析和地球化学，以解决上述问题。

The Limpopo Province in southern Africa is a high-grade metamorphic belt that represents the exhumed root of a continent- continent collision zone. Granite-greenstone terranes of the Zimbabwe Province, to the north, and Kaapvaal Province to the south, flank the Limpopo Province. On the Kaapvaal craton, the Witwatersrand Supergroup is interpreted as a foreland-basin fill, representing the sedimentary response to collisional events in the Limpopo orogeny. A sedimentary succession of comparable lateral extent, thickness, and lithology to the Witwatersrand Supergroup is not present in the Zimbabwe Craton adjacent to the northern marginal zone of the Limpopo Province. Instead, five local and lithologically distinct stratigraphic successions of different age are present in the greenstone belts. At least four of these successions, developed in the lower and upper greenstones, are of comparable age to the Witwatersrand Supergroup. The absence of a Witwatersrand equivalent in Zimbabwe raises several important questions regarding the evolution of the southern African Archean in specific, and Archean tectonics and sedimentation patterns in general: 1) What are the detailed characteristics of two of the 3.0-2.7 Ga Zimbabwean basins, including source-area composition, source-area age, source-area location, sediment dispersal patterns, depositional environments, basin configuration, basin evolution, and tectonic setting? 2) What was the genetic relationship of the Zimbabwe sedimentary basins with respect to the evolution of the Limpopo orogeny? 3) Was the Limpopo orogeny of Pyrenean or Himalayan type? A multidisciplinary approach, involving detailed field mapping, structural analysis, sedimentologic-stratigraphic analysis, and geochemistry, will be applied to two of the stratigraphic successions to address the above questions.