petrology
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Legacy product - no abstract available
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Legacy product - no abstract available
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Legacy product - no abstract available
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Legacy product - no abstract available
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Legacy product - no abstract available
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Subduction of oceanic crust at an unusually low angle (flat-subduction) has been proposed as a general model for the growth of continental crust older than about 2.5 Ga. At modern zones of flat subduction, magmatic additions to new crust come from partial melting of both the subducting oceanic crust (slab) and the thin wedge of mantle above the slab. Evidence for both a slab and wedge source is commonly preserved in some, but not all, late Archaean (3.0-2.5 Ga) terrains, but we find little evidence that a mantle wedge contributed to early Archaean (>3.0 Ga) crustal growth. In contrast to most modern terrains and some late-Archaean terrains, early Archaean continental crust evolved through direct melting of thick mafic crust.
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No abstract available
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p.15
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An informative guidebook outlining the spectacular geological features of the Warrumbungles and their origins. Discover the volcanic evolution of this area over the last 17 million years. Illustrated with cross-sections, photographs and maps and includes a glossary of relevant terms. Suggested walking trails included with their geological features and points of interest.
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This report describes the ornamental stones used in the ground floor foyer of the Geoscience Australia building. There are three ornamental stones used. The flooring tiles are basalt. The 'fault' line through this is a polished norite and the blade walls are covered by a Persian red Travertine. Investigations have established that the basalt and norite are from Australian quarries and the travertine is from an unknown source overseas possibly Italy.