Deciphering the Record of Sediment Transfer and Deposition Across Continental Slopes and the Margins of Other Deep-Water Basins

世界上最深的海洋的海底可以说是地球上最鲜为人知的陆地/海洋景观，主要是因为它们无法进入和相关的极端条件(例如高压)。在我们寻找有关太阳系其他行星(如火星)的信息时，我们的海洋仍然是地球上一个被严重忽视的前沿领域。众所周知，大型水下雪崩或重力流在1-3公里或更深的水深内，通过河状渠道将流体和沉积物输送到大陆边缘的大片海底。不幸的是，直接衡量这些事件往往非常困难，我们被迫通过间接手段了解这些事件，包括破坏海底的基础设施，如通信电缆和管道。更好地理解深海中这些高能事件的另一种方法是研究它们的沉积物，这些沉积物可以在钻芯中捕获，或者在古代例子中，通过重大构造事件上升到山带。拟议的研究将集中在白垩纪时代的深海沉积物，这些沉积物暴露在智利南部和不列颠哥伦比亚省西部露头的地球表面。形成古代海景的巨大重力流的证据已经存在，表现为与冲刷和沟渠有关的深侵蚀面，重力流经过某一地区时留下的独特单元，以及重力流失去能量并静止时积累的厚重沉积物。这项研究需要绘制每个田块露头中露出的地质特征和岩石类型的地图，然后将这些信息纳入三维计算机模型，以揭示地貌特征(如水道)的几何形状及其组成岩石类型的特征。通过研究智利和不列颠哥伦比亚省的这些古老沉积物，我们将深入了解可以说是地球上最后一个真正的前沿地区的沉积物转移：我们的深海。这项研究的一个重要应用动机是更好地约束加拿大边缘和全球其他大陆斜坡上潜在的含油气深水岩石。

The floors of the world's deepest oceans arguably represent the most poorly understood land-/sea-scape on the planet, owing primarily to their inaccessibility and associated extreme conditions (e.g., high pressure). As we seek information about other planets in our solar system such as Mars, our oceans remain a significantly understudied frontier on planet Earth. Large subaqueous avalanches, or gravity flows, are known to transport fluid and sediment through river-like channels across vast expanses of the seafloor on continental margins, in water depths of 1-3 km or more. Unfortunately, direct measurement of these events is often very difficult, and we are forced to draw insight about them from indirect means, including destruction of infrastructure on the seafloor such as communication cables and pipelines. Another means to better understand these high-energy events in the deep-sea is to study their deposits, which can be captured in drillcores, or in the case of ancient examples, uplifted into mountain belts by major tectonic events. The proposed research will focus on Cretaceous-aged deep-sea deposits that are exposed at the Earth's surface in outcrops of southern Chile and western British Columbia. Evidence for immense gravity flows that shaped the ancient seascapes are present, represented by deep erosion surfaces associated with scours and channels, distinctive units that were left behind as gravity flows passed over an area, and thick deposits that accumulated when gravity flows lost their energy and came to rest. The research entails mapping geological features and rock types exposed in outcrops in each field area, and then incorporating the information into three-dimensional computer models, which reveal the geometry of geomorphological features (e.g., channels) and the character of their component rock types. By studying these ancient deposits in Chile and British Columbia, we will gain insight into sediment transfer in arguably the last true Earthly frontier: our deep oceans. An important applied motivation for this study is to better constrain potential hydrocarbon-bearing deep-water rocks on the margins of Canada and other continental slopes around the globe.