Authors / CoAuthors
Thompson, J.E.
Abstract
During a geological reconnaissance of Manus Island, nodular bauxite deposits were observed in three widely separated localities. The occurrences are not laterally connected. Two are derived from basaltic flows and the third is formed over a medium-grained rock probably of tuffaceous origin. These volcanic rocks are products of a comparatively recent vulcanism and they unconformably overlie recrystallised limestones and marine tuffaceous sediments deposited on a plutonic basement. Palaeontological evidence of the age of these sediments is lacking but it is probable that they are Miocene or younger. The volcanics are sub-horizontal or possess a low primary dip determined by the underlying surfaces. The process of bauxitization has been more rapid than usual indicating that physiographic and petrographic conditions have been particularly favourable. Present day conditions of high temperatures, high rainfall and slow drainage are recognised as favourable. It is probable that these conditions have prevailed since the volcanics were laid down and that bauxitization is still proceeding. Regional considerations suggest that the bauxites will be widespread, particularly over the western end of the island. The deposits described were only observed as residual concentrations of bauxite nodules at the surface. They have not been tested as depth. The results of analyses of individual nodules from two of the deposits show a high available alumina content. Further prospecting and testing at depth, particularly in the west, is strongly recommended.
Product Type
document
eCat Id
9310
Contact for the resource
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Custodian
Cnr Jerrabomberra Ave and Hindmarsh Dr GPO Box 378
Canberra
ACT
2601
Australia
Keywords
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- GA PublicationRecord
- ( Theme )
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- geology
- ( Theme )
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- topography
- ( Theme )
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- stratigraphy
- ( Theme )
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- structural geology
- ( Theme )
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- mineral deposits
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- PG
- Australian and New Zealand Standard Research Classification (ANZSRC)
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- Geology
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- Published_External
Publication Date
1952-01-01T00:00:00
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unknown
Topic Category
geoscientificInformation
Series Information
Record 1952/082
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Legacy product, lineage not available
Parent Information
Extents
[-2.3, -1.9, 146.5, 147.5]
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