Origin and Evolution of the Amerasia Basin of the Arctic

Stanford University, Stanford CA

Investigators

Abstract

The geologic history of the remote, ice covered Arctic is still just beginning to be understood. The deep Amerasia ocean basin has never been scientifically drilled and represents one of the few remaining plate tectonic puzzles on earth. Scientists disagree, for instance, on whether Alaska lay next to Canada or Russia before sea floor spreading opened the Amerasia Basin. These basic geologic questions are important because sea floor spreading was also responsible for the development of the vast system of wide continental shelves that border the Arctic, now considered frontier regions for natural resource exploration. Interest in the Arctic has also accelerated because of the profound effect of global warming and because the nations that encircle the Arctic are charting their continental shelves and slopes to propose extensions to their offshore economic zones (EEZs) per U.N. Convention for Law of the Sea, Arcticle 76. This project will provide funding for students and scientists to gather new data to help us understand the plate tectonic evolution of the Amerasia Basin by thoroughly characterizing rock samples collected by dredging submarine cliffs with the U.S. Coast Guard Icebreaker Healy as part of the U.S./Canada EEZ study. The project will also initiate an international collaborative study with Russian scientists to test hypothetical matches between the geology of the Polar Ural region to that of Alaska. Testing ideas and establishing geologic ties within and across the Arctic Ocean basins will utilize traditional stratigraphic, paleontological, geologic and geochronologic approaches augmented by the study of the U-Pb age distributions and the geochemical/physical characteristics of detrital zircon and apatite suites in sandstones. Mostly derived from the erosion of granitic rocks, detrital zircon and apatite suites provide unprecedented ability to link sediments to their source regions and to understand their subsequent burial/thermal history. Our evolving database for sandstones from the NE Russian Arctic and Alaska, coupled with data from other scientists from Canada and Alaska will provide the context for interpreting the origin of continental rocks dredged from the bottom of the Amerasia Basin in 2008 and 2009 (with more sampling planned for 2010 and 2011) and will serve as a comparison data set for samples from the Polar Ural region of Russia.