Early neoproterozoic evolution of the Amundsen Basin

这项拟议的研究将调查被称为沙勒超群的4公里厚的沉积岩序列，这些岩石在西北地区维多利亚岛西北部暴露得很好。前驱沉积物大约在10亿年前沉积在阿蒙森沉积盆地。该盆地位于古老的超大陆罗迪尼亚，记录了地球从超大陆合并到大约2.5亿年后解体的环境历史。拟议的详细沉积学、地层学和地球化学研究将建立在以前研究的基础上，从而更好地了解地球历史上一个鲜为人知的时期的更大规模的构造、地球化学和生物演化。将解决的问题包括：1)阿蒙森盆地是不是间歇性地向外部海洋开放的更大盆地的一部分？如果Shaler超群代表的是罗迪尼亚大盆地中的沉积，那么当罗迪尼亚分裂时，盆地另一边分离出来的相关沉积地层在哪里？这些信息，结合平行研究的信息，将有助于我们重建Rodinia。2)这些内陆盆地的下沉机制是什么？如何解释所观察到的盆地限制和公海条件的间歇性循环？此外，这种旋回的持续时间和机制是什么？3)当时加拿大西北部的古代地理是什么？这与其他大陆(如澳大利亚、西伯利亚)提出的类似年代岩石的古地理模型如何吻合？

The proposed research will investigate a 4 km-thick succession of sedimentary rocks known as the Shaler Supergroup that are well-exposed on northwestern Victoria Island, Northwest Territories. The precursor sediments were deposited in the Amundsen sedimentary basin nearly 1 billion years ago. The basin was situated within an ancient supercontinent, Rodinia, and records Earth's environmental history from the time of supercontinent amalgamation until its break-up about 250 million years later. The proposed detailed sedimentological, stratigraphic and geochemical studies will build upon previous research, leading to a greater understanding of larger-scale tectonic, geochemical and biological evolution during a poorly understood period of Earth's history. Questions that will be addressed include: 1) was the Amundsen basin part of a larger basin that was intermittently open to an exterior ocean? If the Shaler Supergroup represents deposition in a large basin within Rodinia, where are the correlative sedimentary strata from the other side of the basin that were separated when Rodinia broke apart? Such information, combined with that from parallel studies, will help us to reconstruct Rodinia. 2) What was the mechanism of subsidence in these interior basins and how does one explain the intermittent cycles of basin restriction and open ocean conditions that are observed? Further, what was the duration and mechanism of this cyclicity? 3) What was the ancient geography of north-western Canada at this time and how does that fit with paleogeographic models proposed for similar-age rocks on other continents (e.g. Australia, Siberia)?