A paleomagnetic and relative paleointensity record from the Argentine Basin (western South Atlantic Ocean) for the last ∼125 kyrs

Author(s): Heil, Clifford W., Jr.; Stoner, Joseph S.; St-Onge, Guillaume; King, John W.
Author Affiliation(s): Primary:
University of Rhode Island, Narragansett, RI, United States
Oregon State University, United States
University of Quebec at Rimouski, Canada
Volume Title: AGU 2015 fall meeting
Source: American Geophysical Union Fall Meeting, Vol.2015; American Geophysical Union 2015 fall meeting, San Francisco, CA, Dec. 14-18, 2015. Publisher: American Geophysical Union, Washington, DC, United States
Note: In English
Summary: The paucity of paleomagnetic records from the western South Atlantic Ocean presents a significant gap in our understanding of the spatial variations in geomagnetic field dynamics as they relate to the occurrence of geomagnetic excursions and changes in field strength. As such, high quality records from this region can help build upon Holocene observations and extend the geographic and temporal data coverage for spherical harmonic models. To that end, we present paleomagnetic directional (inclination) and strength (relative paleointensity) records from two cores from the Argentine Basin (RC11-49 and RC16-88). Although the cores were collected more than 40 years ago, the sediments appear to hold a stable remanence and reliable magnetic directions, as evidenced by their reproducibility between the two cores that are separated by ∼25 km. The records show evidence of 4 excursional features in the uppermost 16-m of the sediments from the basin. A comparison of the relative paleointensity records from these cores to the South Atlantic Paleointensity Stack (SAPIS) (Stoner et al., 2002) and the relative paleointensity record from ODP Site 1089 (Stoner et al., 2003) indicate that the sediments reliably record relative changes in geomagnetic field intensity and suggests that the longest record (RC11-49) spans the last ∼125 kyrs. Our results indicate that the sediments of the Argentine Basin are an important sedimentary archive of geomagnetic field behavior and strength at least through the Holocene and late Pleistocene and highlight the need for further studies of cores within the basin.
Year of Publication: 2015
Research Program: ODP Ocean Drilling Program
Key Words: 07 Marine Geology and Oceanography; Argentine Basin; Atlantic Ocean; Cape Basin; Cenozoic; Cores; Leg 177; Marine sediments; ODP Site 1089; Ocean Drilling Program; Paleomagnetism; Quaternary; Sediments; South Atlantic
Coordinates: S405611 S405611 E0095338 E0095338
Record ID: 2016082444
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