Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
6445403 | Quaternary Science Reviews | 2016 | 16 Pages |
Abstract
The sediment sequence from Integrated Ocean Drilling Program (IODP) Site U1304 (53°03.40â²N, 33°31.78â²W; water depth, 3024 m) on the southern Gardar Drift, North Atlantic Ocean, covers the last â¼1.8 Myr with a mean sedimentation rate of â¼15 cm/kyr. At Site U1304, paleomagnetic directional and relative paleointensity (RPI) records have been generated for the last â¼1.5 Myr, and benthic oxygen isotope data for the last â¼1 Myr. The age model for Site U1304 was established by matching δ18O and RPI data to calibrated reference records. Prominent intervals of diatom mats at Site U1304 are associated with the latter stages of interglacial marine isotope stages (MIS) 9, 11, 13, 15, 21, 27 and 35, and with the weak glacial of MIS 14. The deposition of diatom mats, and associated diluted magnetic mineral concentrations, leads to weak magnetizations and susceptibilities in these intervals. Comparison of histograms of paleomagnetic directions and RPI from diatom-rich sediments and from surrounding silty clays indicates that, although results from diatom-rich sediments are more scattered, the occurrence of diatom mats does not appreciably distort the paleomagnetic directional and RPI records. Site U1304 sediments record the Matuyama/Brunhes boundary (â¼772 ka), the Jaramillo Subchron (â¼993-1071 ka) and the Cobb Mountain Subchron (â¼1193-1219 ka), as well as three apparent geomagnetic excursions in the Matuyama Chron, interpreted as the “Kamikatsura/Santa Rosa”, “Punaruu”, and “Gardar” excursions, at â¼888 ka, â¼1124 ka, and â¼1463 ka, respectively. The Site U1304 RPI record can be correlated with the PISO-1500 RPI stack and with other high-resolution RPI records from the North Atlantic Ocean. Wavelet analyses performed on the Site U1304 RPI record and a new high-resolution North Atlantic paleointensity stack for the last 1500 kyr (HINAPIS-1500), comprising Ocean Drilling Program (ODP) Sites 983, 984 and IODP Sites U1306 and U1304, did not reveal significant orbital power.
Related Topics
Physical Sciences and Engineering
Earth and Planetary Sciences
Geology
Authors
Chuang Xuan, James E.T. Channell, David A. Hodell,