Collaborative Research: Testing Precambrian Siberia-Laurentia Geologic Connections with U-Pb Geochronology

根据古地磁资料、基底穿透点和裂谷边缘的最佳拟合度，重建了西伯利亚-西劳伦西亚克拉通，对齐了元古界岩脉/地台群，并置了元古界盆地。在这个俄美合作项目中，PI通过检查火成岩的结晶年龄以及在西劳伦萨和东西伯利亚克拉通边缘截断的沉积岩的地层和碎屑锆石系统学来测试恢复情况。具体地说，他们计划进行以下测试。1)可能连接西伯利亚北部Anabar地块与蒙大拿州西南部的Belt-Purcell盆地和毗邻基底的脉岩基台群的U-Pb定年；2)西伯利亚北部碎屑岩碎屑锆石的U-Pb定年，可能与成熟的Belt-Purcell超群有关；3)西伯利亚东南部Uy群中部和死亡谷金斯顿峰形成的可能形成一个大型火成岩省的基床群和流动的U-Pb定年；4)西伯利亚东南部Uy和Yudoma群碎屑岩碎屑锆石的U-Pb定年以及可能相互关联的金斯顿峰地层和死亡谷的正午白云岩，它们可能构成了一个盆地的一部分。申请的资金将包括前往死亡谷和西伯利亚东南部的互惠地质旅行，随后将开展U-Pb地质年代学实验室工作。PI还将确定俄罗斯地质学家之前收集的样本的日期。如果该项目最终证明西伯利亚-劳伦西亚恢复的有效性，那么它将产生重大的地质影响，因为这是更广泛的罗迪尼亚超大陆假说的关键组成部分，并对几个地质和地球动力学问题产生影响，包括全球冰期、真极地漂移、冈瓦那的形成和寒武纪的后生动物革命。如果结果被证明是否定的，这项研究将消除对罗迪尼亚的一种潜在解释，并将为西伯利亚和劳伦斯元古界的地质演化提供有价值的新约束。更广泛的影响包括由赠款支持的对地球科学学生的高级培训，通过国际科学合作促进和平与科学进步，以及对俄罗斯科学基础设施的支持。

Abstract Reconstruction of a Siberia-west Laurentia craton, in accordance with paleomagnetic data, basement piercing points, and the best fit of the rift margins, aligns Proterozoic dike/sill swarms and juxtaposes Proterozoic basins. In this collaborative Russian-American project, the PI's test the restoration by examining the crystallization ages of igneous rocks and the stratigraphy and detrital zircon systematics of sedimentary rocks that are truncated at the west Laurentian and east Siberian cratonic margins. Specifically, they plan the following tests. 1) U-Pb dating of a dike-sill swarm that may link the Anabar massif of north Siberia with the Belt-Purcell basin and adjacent basement of southwest Montana and Wyoming.2) U-Pb dating of detrital zircons from clastic rocks of northern Siberia that may link to the well-dated Belt-Purcell Supergroup.3) U-Pb dating of sill swarms and flows in the middle Uy Group of southeast Siberian and Kingston Peak Formation of Death Valley that may have formed one large igneous province.4) U-Pb dating of detrital zircons from clastic rocks in the Uy and Yudoma groups of southeast Siberian and potentially correlative Kingston Peak Formation and Noonday Dolomite of Death Valley that may have comprised parts of one basin. Requested funds will cover reciprocal geological excursions to Death Valley and southeast Siberia, to be followed by U-Pb geochronological lab work. The PI's will also date samples previously collected by Russian geologists. The project will have significant geological impact should it conclusively demonstrate the validity of the Siberia-Laurentia restoration because this is a critical component of the broader Rodinia supercontinent hypothesis, and has implications for several geologic and geodynamic problems, including global ice ages, true-polar wander, formation of Gondwana, and the Cambrian metazoan revolution. Should the results prove negative, the study will remove one potential interpretation for Rodinia, and will also provide valuable new constraints for Siberian and Laurentian Proterozoic geological evolution. Broader impacts include the advanced training of geoscience students supported by the grant, the promotion of peace and advancement of science through international scientific collaboration, and support of the Russian scientific infrastructure.