RAPID: CT-imaging of IODP Expedition 341 Plio-Pleistocene Strata from the Gulf of Alaska

Oregon State University, Corvallis OR

Investigators

Abstract

Integrated Ocean Drilling Program (IODP) Expedition 341 recovered 3240 m of Miocene-to-recent strata from Sites U1417-U1421 in the northern Gulf of Alaska, arranged in a cross-margin transect to sample sediment supplied from the mountains during a period of dramatic Neogene climate change. These cores provide a unique high-latitude sedimentary record of both marine and terrestrial systems and thus the demand for the samples from the scientific community is expected to be very high. Before these cores are irreversibly cut up and sampled, Principal Investigators request support to acquire non-intrusive CT-scans of high-priority, high-resolution sections in selected cores to optimize utilization of these sediments for achieving the scientific objectives of the expedition. This requires rapid action before the main core sampling occurs (mid-Nov. 2013) to insure that the material is correctly sampled and that disturbed intervals or critical laminae that are not obvious to the eye in these complex ice-proximal sediments are not sampled. To accomplish the work in time to guide the main sampling work, Principal Investigators propose to use CT scanners at the Oregon State University College of Veterinary Medicine (adjacent to the OSU Core Repository) and the at the Institut National de Recherché Scientifique, Centre Eau, Terre et Environnement (INRS-ETE) in Quebec City, Canada. Both facilities are accessible by shipboard participants Mix (OSU)and St. Onge (U. Quebec Rimouski), who are acting as representatives of the larger scientific party. Intellectual Merit: Documenting facies with CT-images and establishing the links to the modern sedimentary environment of Alaska will provide key constraints of sedimentological changes at the scale of laminae. Understanding the history of these sedimentary processes is a central goal of IODP Expedition 341, part of assessing the dynamic changes in the Cordilleran Ice Sheet, and the linkage between glaciation, erosion, uplift, and sedimentation, and the role of ocean-icesheet-climate interaction in driving these changes. Broader Impacts: The CT-scans will benefit the entire expedition party plus future samplers, but must be done prior to the main core sampling in November 2013, thereby necessitating RAPID support. This study will contribute to larger expedition goals, including collaborations among researchers from 13 countries. Principal Investigators expect that these CT-scans will provide a legacy dataset used by the larger scientific community long into the future. In addition, the extraordinary visualizations provided by these data will provide opportunities for public education and outreach for IODP and geosciences. These exceptional datasets will be archived as an IODP Publication and will be freely available to the public