SGER Award-Exploratory Work in Rondonia - the Laurentia-Amazonia Connection

大多数罗迪尼亚板块重建提出亚马逊河克拉通西部与劳伦西亚3000公里长的格伦维尔边缘的某些部分并置。这种联系是基于连接古代大陆边缘的年龄相似（约1.2-0.95 Ga）的活动带。然而，由于对亚马逊河西部地块的变质史和构造史的不了解，阻碍了对劳伦蒂亚-亚马逊河构造的测试。该提案要求为最近暴露的地区的勘探工作提供资金，以利用构造测绘、变质岩石学和地质年代学记录西亚马逊克拉通的变形历史。将与巴西地质局（CPRM）合作，对位于亚马逊克拉通边缘的巴西西部朗多尼亚州的两个关键地区进行初步测绘和样本收集。该项目的实验室部分将侧重于压力和温度（P-T）条件和地质年代学（使用40Ar/39Ar和U/Pb系统），以确定峰值变质和变形的时间。这些数据将测试该地区一个更大项目的可行性，以更深入地了解晚元古代劳伦西亚-亚马逊河流域的相互作用。

Most Rodinia plate reconstructions propose juxtaposition of the western Amazon craton with some segment of the 3000 km long Grenville margin of Laurentia. This connection is based on linking similarly aged (ca. 1.2-0.95 Ga) mobile belts across ancient continental margins. However, poor understanding of the metamorphic and structural history of the western Amazon block has prevented a test of these Laurentia-Amazonia configurations. This proposal requests funding for exploratory work in recently exposed field areas to document the deformational history of the western Amazon craton using structural mapping, metamorphic petrology and geochronology. Preliminary mapping and sample collecting of twokey regions in the western Brazilian state of Rondonia, located on the margin of the Amazon craton, will be undertaken in collaboration with the Brazilian Geological Service (CPRM). The laboratory portion of this project will focus on pressure and temperature (P-T) conditions and geochronology (using 40Ar/39Ar and U/Pb systems) for the timing of peak metamorphism and deformation. These data will test the feasibility of a larger project in the area toward a firm understanding of Laurentia-Amazonia interactions in lateProterozoic times.