Paleolatitudinal constraints from Eocene to Recent sediments cored in the Equatorial Pacific on IODP Expeditions 320 and 321

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Author(s): Acton, Gary; Richter, Carl; Yamamoto, Yuhji; Ohneiser, Christian; Yamazaki, Toshitsugu; Channell, James E. T.; Evans, Helen F.; Petronotis, Katerina E.; Guidry, Emily P.
Author Affiliation(s): Primary:
Sam Houston State University, Huntsville, TX, United States
University of Louisiana at Lafayette, United States
Kochi Core Center, Japan
University of Otago, New Zealand
University of Tokyo, Japan
University of Florida, United States
Shell Exploration and Production Company, United States
Volume Title: AGU 2016 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2016; American Geophysical Union 2016 fall meeting, San Francisco, CA, Dec. 12-16, 2016. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: Sediments cored along a Pacific Equatorial Age Transect (PEAT) during Integrated Ocean Drilling Program (IODP) Expeditions 320 and 321 record the paleomagnetic field with high fidelity, providing new paleolatitudinal constraints for the Pacific Plate. A total of 6,141 m of core was recovered from 23 holes cored at 8 sites (Sites U1331 through U1338), which are currently located at latitudes between 2.5°N and 12.1°N. Paleomagnetic data were collected from discrete samples (7 cm3 cubes) that were subjected to progressive alternating field (AF) and thermal demagnetization and were collected every 1 cm along U-channel samples (2 cm × 2 cm × 150 cm) and every 5 cm or less along split-core sections that were subjected to progressive AF demagnetization. The age of the sediment is well constrained from unambiguous magnetostratigraphies and from biostratigraphic data, as well as by subsequent astronomical tuning using cyclic variations in the physical, chemical, and magnetic properties of the sediments. The large amount of paleomagnetic data collected within each magnetic chron makes it possible to compute the change in paleolatitude with high temporal resolution and to investigate polarity asymmetries, overprints, and other possible biases. The good spatial (latitudinal) distribution of the sites along with the general northward motion of the Pacific Plate provide observations that help resolve possible biases caused by flattening, which is inherently small for near equatorial sites but, even so, possibly resolvable given the large number of paleomagnetic data.
Year of Publication: 2016
Research Program: IODP Integrated Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; East Pacific; Expedition 320; Expedition 321; Expeditions 320/321; IODP Site U1331; IODP Site U1332; IODP Site U1333; IODP Site U1334; IODP Site U1335; IODP Site U1336; IODP Site U1337; IODP Site U1338; Integrated Ocean Drilling Program; North Pacific; Northeast Pacific; Pacific Ocean
Coordinates: N023028 N023028 W1175811 W1175811
N120405 N120405 W1420942 W1420942
N103100 N103100 W1382510 W1382510
Record ID: 2017068181
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