Jura-Cretaceous Back-Arc Basin Evolution and Collisional Tectonics of West-Central British Columbia

将对不列颠哥伦比亚省中西部的Skeena群进行盆地分析，以评价早白垩世的构造和地体碰撞的力学。被检验的模式是最初的地体碰撞导致两个俯冲带的合并和晚侏罗世至早白垩世Skeena Arch的抬升。渐进式碰撞导致活动弧后的拱门向西扩张。早白垩世下沉，斯基纳群沉积于弧后盆地。本研究的两个假设是(1)弧后沉降是伸展或伸展的结果，或(2)沉降是由缩短、构造载荷和岩石圈挠曲引起的。识别标准将包括沉积物来源、相分析、沉降史、古流分析、成岩史和互层火山岩的微量元素地球化学。这一研究结果将对侏罗纪-白垩纪太平洋盆地和法拉隆板块的演化具有重要意义。

A basin analysis of the Skeena group of west-central British Columbia will be undertaken to evaluate Early Cretaceous tectonics and mechanics of terrane collision. The model to be tested is that initial terrane collision resulted in the mergence of two subduction zones and uplift of the Late Jurassic to earlier Cretaceous Skeena Arch. Progressive collision led to the expansion of the arch behind an active arc to the west. The arch subsided in the Early Cretaceous and the Skeena Group were deposited in the back-arc basin. The two hypotheses that this study will address are (1) back arc subsidence was the result of extension or transtension, or (2) subsidence was due to shortening, tectonic loading and lithospheric flexure. Distinguishing criteria will include sediment provenance, facies analysis, subsidence history, paleocurrent analysis, diagenetic history, and trace element geochemistry of interbedded volcanics. The results of this study will have important implications for the evolution of the Jurassic- Cretaceous Pacific basin and the Farallon plate.