Collaborative Research: The Role of the Porcupine Fault System in the Mesozoic Opening of the Arctic Ocean

Dartmouth College, Hanover NH

Investigators

Abstract

Despite its proven economic resources, the Arctic Ocean is the last modern ocean basin on the planet whose origin remains highly controversial. This is largely due to its perennial ice cover and lack of detailed scientific examination by shipborne research vessels. The goal of the proposed research is to examine the Porcupine fault system in northeastern Alaska and northwestern Yukon, Canada, which likely played an important, yet poorly understood, role in the opening of the Arctic Ocean. The study promotes a new collaboration between early career and senior academic researchers at four U.S. institutions and government research agencies in both the United States and Canada, including the development of a new geologic mapping effort across the international border. The collaborative international effort will generate research opportunities and training for undergraduate and graduate students at the academic institutions, as well as educational and outreach opportunities in a rural Native Alaskan community in collaboration with the United States Fish and Wildlife Service and Las Vegas, NV, through integration with the NSF-supported GeoPaths program. Results of the project will also be conveyed to the public through the development of an informational pamphlet sponsored and distributed by the U.S. Fish and Wildlife Service in Alaska, as well as accessible public lectures at the participating universities. The canonical tectonic model for the opening of the Canada Basin of the Arctic Ocean involves greater than 60º counterclockwise rotation of northern Alaska away from the Canadian Arctic Islands in the Jurassic–Cretaceous, but more recent models highlight potentially significant strike-slip displacement along the northern margin of North America. Critically, little is known about the fault systems that may have accommodated these margin-parallel displacements. The goal of the proposed research is to examine the Porcupine fault system, a long-lived craton-bounding structure in northeastern Alaska and northwestern Yukon, Canada, that has a poorly understood Mesozoic–Cenozoic reactivation history but likely played a role in the opening of the Canada Basin. The reflects a new collaboration between Early Career and senior academic researchers, federal and state/territory geoscientists, and undergraduate/graduate students that will not only further our understanding of Mesozoic–Cenozoic tectonic and paleogeographic models for the circum-Arctic, northern Pacific, and northern North American Cordillera, but it will also provide new insights into the dynamics and chronology of crustal deformation in polyphase brittle fault systems. In addition, the research will test the utility and feasibility of combining multiple established and new fault geo- and thermo-chronometers to these complex systems. As a result, this project will generate broad interest from the tectonics, structural geology, and geo-/thermo-chronology communities, as well as cross-disciplinary interest in Arctic sciences, economic geology, sedimentary geology, petrology, geophysics, and geodynamics. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.