The new UWA Research Repository can be accessed at the following link: http://research-repository.uwa.edu.au. Please update your favourites accordingly
Collections > Natural and Agricultural Sciences > Earth and Environment
Refine your search
Brief view Table view Full view
Sort by:
Record 1 of 898 1 2 3 4 Next Page

SFX
 
 
Citation
FIORENTINI, M. & GARWIN, S.L. (2010). Evidence of a mantle contribution in the genesis of magmatic rocks from the Neogene Batu Hijau district in the Sunda Arc, South Western Sumbawa, Indonesia. Contributions to Mineralogy and Petrology, 159(6), 819-837.
Title
Evidence of a mantle contribution in the genesis of magmatic rocks from the Neogene Batu Hijau district in the Sunda Arc, South Western Sumbawa, Indonesia
Author
Year
2010
Published in
Abstract
Whole-rock geochemical and radiogenic data are combined with in situ trace and isotopic analyses of amphibole grains to characterize the source and the emplacement mechanisms of the magmas of the Sunda arc in the Batu Hijau district, Sumbawa, Indonesia. The low-K calc-alkaline magmatic suite in the area is characterized by a distinctively juvenile signature (143Nd/144Nd ~0.5130). Whole-rock trace element and Pb isotopic data (207Pb/204Pb ~15.603) suggest the involvement of a minimal (<0.1%) sediment component in arc petrogenesis. During the petrogenesis of the calc-alkaline plutons, the involvement of fluids that were not entirely derived from the dehydration of a subducting slab is reflected in the mineral chemistry of the primary hydrous magmatic amphiboles, which contain very low B and Li concentrations. We argue that the B- and Li-poor fluids implicated in the petrogenesis of the calc-alkaline melts were at least partially derived from dehydration of uprising asthenospheric mantle. The δD values of selected hydrous magmatic amphibole grains range between ca. −70‰ and 0‰, consistent with an original mantle-derived signature, which was subsequently modified due to a de-hydrogenation process. We put forward the hypothesis that in the Batu Hijau district an arc-transverse fault system facilitated the rise of asthenosphere-derived melts above a kink, or tear, in the subducting Indian Ocean Plate that underlies the Sunda arc. The melts ascended to upper-crustal levels and underwent fractionation while interacting with the arc crust or metasomatized lithospheric mantle wedge. As a result of this study, we emphasize the significance of crustal-scale faults as conduits that connect the mantle to upper-crustal levels in arc settings. The de-hydrogenation process that the tonalite plutons underwent in the Batu Hijau district may have been crucial to the genesis of
associated Cu–Au porphyry mineralization and the development of the Pliocene Batu Hijau deposit. Consequently, we argue that deep structures may facilitate the efficient release of mineralizing fluids at high crustal-levels.
Identifier
http://dx.doi.org/10.1007/s00410-009-0457-7
Identifier
FIORENTINI, M. & GARWIN, S.L. (2010). Evidence of a mantle contribution in the genesis of magmatic rocks from the Neogene Batu Hijau district in the Sunda Arc, South Western Sumbawa, Indonesia. Contributions to Mineralogy and Petrology, 159(6), 819-837.
Identifier
0010-7999
Identifier
http://repository.uwa.edu.au:80/R/-?func=dbin-jump-full&amp;object_id=28049&amp;silo_library=GEN01
ISBN/ISSN
0010-7999
Subject
Department/School
Type
Journal article
Additional Information
Link to Publisher's website supplied in Alternative Location.
Alternative Location
DOI
Persistent URL
http://repository.uwa.edu.au:80/R/-?func=dbin-jump-full&amp;object_id=28049&amp;silo_library=GEN01
Related collections
Natural and Agricultural Sciences > Earth and Environment