Magnetic properties of sediments from Ocean Drilling Program sites 1109, 1115, and 1118 Leg 180, Woodlark Basin Papua New GuineaReportar como inadecuado




Magnetic properties of sediments from Ocean Drilling Program sites 1109, 1115, and 1118 Leg 180, Woodlark Basin Papua New Guinea - Descarga este documento en PDF. Documentación en PDF para descargar gratis. Disponible también para leer online.

Earth, Planets and Space

, Volume 54, Issue 9, pp 883–897

First Online: 21 June 2014Received: 14 December 2000Revised: 24 July 2002Accepted: 30 July 2002

Abstract

Latest Miocene-Pleistocene synrift sediments at Ocean Drilling Program sites 1109, 1115, and 1118 Leg 180, located on the hanging wall margin north of the Moresby fault in the Woodlark Basin, showed variations in magnetic parameters carried by magnetite and maghemite related to sedimentation process in the basin. At sites 1109 and 1115, an increase in the sedimentation rate at 3.8 Ma was accompanied by the deposition of sediments with low ferrimagnetic mineral concentrations. An increase in the ferrimagnetic mineral concentrations occurred between 3.4 Ma and 3.2 Ma at the three sites. The onset age of the change became younger with distance from the subsidence center of the basin near the Moresby fault: 3.4 Ma at Site 1118, 3.3 Ma at Site 1109, and 3.2 Ma at Site 1115, which implies a northward onlapping of sediments with high ferrimagnetic mineral concentration. Sediments with finer-grained ferrimagnetic minerals were deposited between 2.3 and 2.0 Ma at sites 1118 and 1109 and later, 2.8 Ma at Site 1115 during a period of a low sedimentation rate. The upper parts of sites 1109 and 1115 had a diamagnetic contribution, which is attributed to relatively high concentrations of diamagnetic pelagic materials at a low sedimentation rate associated with the low frequency of turbidites.

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Autor: Naoto Ishikawa - Gina Marie Frost

Fuente: https://link.springer.com/







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