Dolerites of the Woodlark Basin (Papuan Peninsula, New Guinea); a geochemical record of the influence of a neighbouring subduction zone

Online Access: Get full text
doi: 10.1016/j.jseaes.2007.12.003
Author(s): Gardien, Véronique; Lécuyer, Christophe; Moyen, Jean-François
Author Affiliation(s): Primary:
Université de Lyon I, Villeurbanne, France
Other:
University of Stellenbosch, South Africa
Volume Title: Journal of Asian Earth Sciences
Source: Journal of Asian Earth Sciences, 33(3-4), p.139-154. Publisher: Elsevier, Oxford, United Kingdom. ISSN: 1367-9120
Note: In English. Based on Publisher-supplied data
Summary: The Moresby Seamount located in the Woodlark Basin is a fragment of oceanic crust (dolerites and gabbros) generated 66.4±1.5 My ago before being obducted during the Eocene on the Australian margin. Since 8 My, the motion of a normal fault related to the opening of the Woodlark Basin is responsible for the unroofing of the Moresby seamount. The latter was sampled during the ODP campaign Leg 180 in 1998. Geochemical compositions of dolerites can be explained by a process of fractional crystallization in which the magnesian spinel was involved. Therefore fractionation processes took place at relatively high pressure (>1 GPa), most likely during the upward migration of deep magmas throughout the mantle. The Fe-rich gabbros, more differentiated than the dolerites, could have derived from an early differentiated magma evolving in the crust at relatively low pressures. The trace element content of dolerites indicates that their source was a depleted oceanic mantle slightly influenced by arc-related magmas. This study suggests that the ophiolites fragment of the Moresby seamount was created in the vicinity of a subduction zone; this model being in agreement with the regional tectonic setting of SE Asian since the Cainozoic. Abstract Copyright (2008) Elsevier, B.V.
Year of Publication: 2008
Research Program: ODP Ocean Drilling Program
Key Words: 02 Geochemistry; 05 Petrology, Igneous and Metamorphic; Australasia; Australian Plate; Basins; Cenozoic; Chemical composition; Coral Sea; Crust; Diabase; Eocene; Faults; Fractional crystallization; Gabbros; Geochemistry; Igneous rocks; Leg 180; Magmas; Magmatic differentiation; Major elements; Modal analysis; Models; Moresby Seamount; Normal faults; Ocean Drilling Program; Ocean floors; Oceanic crust; Ophiolite; P-T conditions; Pacific Ocean; Paleogene; Papua New Guinea; Papuan Peninsula; Petrology; Plutonic rocks; Seamounts; Solomon Sea; South Pacific; Southwest Pacific; Subduction zones; Tertiary; Trace elements; West Pacific; Woodlark Basin
Coordinates: S095200 S091100 E1513800 E1513200
Record ID: 2011046613
Copyright Information: GeoRef, Copyright 2019 American Geosciences Institute. Reference includes data from CAPCAS, Elsevier Scientific Publishers, Amsterdam, Netherlands