South-Central Section - 50th Annual Meeting - 2016

Paper No. 6-5
Presentation Time: 8:00 AM-5:30 PM

ROCK MAGNETIC AND PALEOMAGNETIC STUDY OF SEDIMENTS FROM IODP SITE U1389 (WEST IBERIAN MARGIN)


ADESIYUN, Oludamilola1, RICHTER, Carl1, ACTON, Gary2, SIDOROVSKAIA, Natalia3, SIERRO, Francisco Javier4, XUAN, Chuang5 and VEROSUB, Kenneth L.6, (1)Geology, University of Louisiana at Lafayette, LAFAYETTE, LA 70504, (2)Geology, Sam Houston State University, Huntsville, TX 77340, (3)Physics, University of Louisiana at Lafayette, LAFAYETTE, LA 70504, (4)Geology, University of Salamanca, Salamanca, Spain, (5)National Oceanography Center, Liverpool, United Kingdom of Great Britain and Northern Ireland, (6)Earth and Planetary Sciences, UC Davis, One Shields Ave, Davis, CA 95616, acedammy@gmail.com

High resolution rock magnetic and paleomagnetic results from a section spanning 36 to 107 meters composite depth of Integrated Ocean Drilling Program (IODP) Site U1389 are discussed. Site U1389 is located in the North Atlantic at 36° 25.515’N; 7° 16.683’W in 644 m water depth. The main objective is to study the Mediterranean Outflow Water (MOW) and its effects on the short term and long term climate and contourite system of the Iberian margin over the past 6 million years. The sedimentary section at Site U1389 consists of a thick and consistent succession of contouritic sediments with sedimentation rates of ~40 cm/kyr. The age model was obtained by tuning planktonic foraminifer oxygen isotope data to the NGRIP ice core record. Through alternating field (AF) demagnetization of the natural remanent magnetization (NRM), the characteristic remanent magnetization is isolated while the low stability component is removed. The average maximum angular deviation, calculated from the principal component analysis is ~1.2°, which illustrates the excellent quality of the preserved magnetic signal. Consistent behavior of the magnetic samples during AF demagnetization and acquisition curves of the isothermal remanent magnetization suggests magnetite as the main magnetic carrier mineral. By normalizing the NRM by the anhysteretic remanent magnetization, isothermal remanent magnetization, and magnetic susceptibility, the relative paleointensity (RPI) was calculated. Spectra analysis of high-resolution concentration and grain-size dependent will be presented with the aim of determining the driver of environmental change.