Expedition 341 summary

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doi: 10.2204/iodp.proc.341.101.2014
Author(s): Jaeger, John M.; Gulick, Sean S.; LeVay, Leah J.; Asahi, Hirofumi; Bahlburg, Heinrich; Belanger, Christina L.; Benedetti Berbel, Gláucia Bueno; Childress, Laurel B.; Cowan, Ellen A.; Drab, Laureen; Forwick, Matthias; Fukumura, Akemi; Ge Shulan; Gupta, Shyam M.; Kioka, Arata; Konno, Susumu; März, Christian E.; Matsuzaki, Kenji M.; McClymont, Erin L.; Mix, Alan C.; Moy, Christopher M.; Müller, Juliane; Nakamura, Atsunori; Ojima, Takanori; Ridgway, Kenneth D.; Rodrigues Ribeiro, Fabiana; Romero, Oscar E.; Slagle, Angela L.; Stoner, Joseph S.; St-Onge, Guillaume; Suto, Itsuki; Walczak, Maureen H.; Worthington, Lindsay L.
Integrated Ocean Drilling Program, Expedition 341 Scientists, College Station, TX
Author Affiliation(s): Primary:
University of Florida, Department of Geological Sciences, Gainesville, FL, United States
Other:
University of Texas-Austin, United States
Integrated Ocean Drilling Program, United States
Lamont-Doherty Earth Observatory, United States
Pusan National University, South Korea
Universität Münster, Germany
South Dakota School of Mines and Technology, United States
Universidade de Sao Paulo, Brazil
Northwestern University, United States
Appalachian State University, United States
University of Tromso, Norway
Nagoya University, Japan
State Oceanic Administration, China
National Institute of Oceanography, India
University of Tokyo, Japan
Kyushu University, Japan
Newcastle University, United Kingdom
Tohoku University, Japan
University of Durham, United Kingdom
Oregon State University, United States
University of Otago, New Zealand
Alfred Wegener Institute, Germany
Purdue University, United States
Instituto Andaluz de Ciencias de la Tierra, Spain
Université du Québec à Rimouski, Canada
Australian National University, Australia
University of New Mexico, United States
Volume Title: Proceedings of the Integrated Ocean Drilling Program; southern Alaska Margin; Expedition 341 of the riserless drilling platform; Victoria, British Columbia (Canada), to Valdez, Alaska (USA); Sites U1417-U1421, 29 May-29 July 2013
Volume Author(s): Jaeger, John M.; Gulick, Sean S.; LeVay, Leah J.; Slagle, Angela L.; Drab, Laureen; Asahi, Hirofumi; Bahlburg, Heinrich; Belanger, Christina L.; Benedetti Berbel, Gláucia Bueno; Childress, Laurel B.; Cowan, Ellen A.; Forwick, Matthias; Fukumura, Akemi; Ge Shulan; Gupta, Shyam M.; Kioka, Arata; Konno, Susumu; März, Christian E.; Matsuzaki, Kenji M.; McClymont, Erin L.; Mix, Alan C.; Moy, Christopher M.; Müller, Juliane; Nakamura, Atsunori; Ojima, Takanori; Ridgway, Kenneth D.; Rodrigues Ribeiro, Fabiana; Romero, Oscar E.; Stoner, Joseph S.; St-Onge, Guillaume; Suto, Itsuki; Walczak, Maureen H.; Worthington, Lindsay L.
Source: Proceedings of the Integrated Ocean Drilling Program; southern Alaska Margin; Expedition 341 of the riserless drilling platform; Victoria, British Columbia (Canada), to Valdez, Alaska (USA); Sites U1417-U1421, 29 May-29 July 2013, John M. Jaeger, Sean S. Gulick, Leah J. LeVay, Angela L. Slagle, Laureen Drab, Hirofumi Asahi, Heinrich Bahlburg, Christina L. Belanger, Gláucia Bueno Benedetti Berbel, Laurel B. Childress, Ellen A. Cowan, Matthias Forwick, Akemi Fukumura, Ge Shulan, Shyam M. Gupta, Arata Kioka, Susumu Konno, Christian E. März, Kenji M. Matsuzaki, Erin L. McClymont, Alan C. Mix, Christopher M. Moy, Juliane Müller, Atsunori Nakamura, Takanori Ojima, Kenneth D. Ridgway, Fabiana Rodrigues Ribeiro, Oscar E. Romero, Joseph S. Stoner, Guillaume St-Onge, Itsuki Suto, Maureen H. Walczak and Lindsay L. Worthington; Integrated Ocean Drilling Program, Expedition 341 Scientists, College Station, TX. Proceedings of the Integrated Ocean Drilling Program (Online), Vol.341, 130p. Publisher: Integrated Ocean Drilling Program Management International for the Integrated Drilling Program (IODP), Washington, DC, United States. ISSN: 1930-1014 CODEN: IDSDA6
Note: In English. 228 refs.; illus., incl. sects., 2 tables, geol. sketch maps
Summary: Global climate during the Neogene is distinguished by the transition into a colder, more variable world dominated by the onset and intensification of major Northern Hemisphere glaciations. This transition into the icehouse world corresponds to a global increase in erosion rates and sediment delivery to ocean basins. The effects of this increased erosion may be profound, as analyses of orogenic belts worldwide have shown that Earth systems cannot be considered to be the product of a series of distinct, decoupled tectonic and climatic processes. Rather, there is complex interplay between crustal deformation, exhumation, and climate systems. Exhumation plays a key role in controlling the regional distribution of metamorphic rocks, local climate change, and the development of structures throughout an orogen. Tectonic processes influence regional climate conditions by raising mountains that alter orographic precipitation patterns. The Neogene climate changes, in turn, likely affected tectonic processes through changes in erosion rates, which redistributed mass and subsequently altered stress regimes in orogenic wedges. Analytical models examining the coupling between glacial erosion and orogenic processes reveal that glacial erosion can significantly modify the patterns and rates of deformation in an orogenic wedge. A critical question is: At which stage of the deteriorating Neogene climate is an orogen ultimately driven into a subcritical state? And does this state lead to increased exhumation in the glaciated core of a mountain belt, enhanced topographic relief, and migration of the locus of sediment accumulation to the toe of an orogen thus impacting deformation patterns? Addressing the linkages between global climate change, modification of surficial process dynamics, and subsequent tectonic responses requires integrated studies of orogenic and sedimentary systems in areas where specific end-members of the problem are encountered. The Gulf of Alaska borders the St. Elias orogen of Alaska and Canada, the highest coastal mountain range on Earth and the highest range in North America. This orogen is <30 m.y. in age, and mountain building occurred throughout a period of significant global climate change. This situation allowed Integrated Ocean Drilling Program Expedition 341 to examine the response of an orogenic system to the climatically driven establishment of a highly erosive glacial system. Additionally, the implications of Neogene glacial growth in the circum-North Pacific reach beyond the issue of tectonic response to increased glacial erosion and exhumation. As climate conditions determine the timing and patterns of precipitation, they control glacial dynamics, erosion, and sediment/meltwater and chemical fluxes to the ocean. Establishing the timing of northwestern Cordilleran ice sheet advance-retreat cycles in southern Alaska will address a major challenge in Neogene paleoclimatology: to determine whether glacial advances occurred synchronously around the world and what the driving mechanisms were for global millennial-scale warming-cooling cycles. Evidence for substantial changes in surface productivity in the Gulf of Alaska since the Last Glacial Maximum indicates that millennial-scale climate changes and eustasy in the northeast Pacific Ocean have a first-order effect on primary productivity and marine ecosystems. Thick Pleistocene glacimarine deposits of the Gulf of Alaska continental margin contain a rich history of climate change recorded in both proxy climate data and sediment accumulation rates that can help decipher the architecture of massive Neogene high-latitude Northern Hemisphere continental margin sedimentary sequences. Exceptionally high rates of glacigenic sediment accumulation in this region also allow for the development of a paleomagnetic record of geomagnetic field variability on sub-millennial scales to assess geomagnetic persistence, a signature of the mantle's influence on the geodynamo and the paleomagnetic record. A cross-margin transect was drilled during Expedition 341 to investigate the northeast Pacific continental margin sedimentary record formed during orogenesis within a time of significant global climatic deterioration in the Pliocene-Pleistocene that led to the development of the most aggressive erosion agent on the planet, a temperate glacial system.
Year of Publication: 2014
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 12 Stratigraphy, Historical Geology and Paleoecology; 20 Geophysics, Applied; Alaska; Algae; Biostratigraphy; C-13/C-12; Carbon; Cenozoic; Chemostratigraphy; Climate change; Continental margin; Cores; Diatoms; East Pacific; Expedition 341; Foraminifera; Geophysical methods; Geophysical profiles; Geophysical surveys; Gulf of Alaska; IODP Site U1417; IODP Site U1418; IODP Site U1419; IODP Site U1420; IODP Site U1421; Integrated Ocean Drilling Program; Invertebrata; Isotope ratios; Isotopes; Lithostratigraphy; Magnetic properties; Magnetic susceptibility; Magnetostratigraphy; Microfossils; Neogene; North Pacific; Northeast Pacific; O-18/O-16; Oxygen; Pacific Ocean; Paleo-oceanography; Paleoclimatology; Paleomagnetism; Physical properties; Plantae; Protista; Quaternary; Radiolaria; Seismic methods; Seismic profiles; Seismic stratigraphy; Southern Alaska; Stable isotopes; Surveys; Tertiary; United States; Well logs
Coordinates: N565700 N594200 W1431200 W1470700
Record ID: 2014105286
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