Geology of Barewood and the Antimony Mine.
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The paper entailed a geological investigation of the Barewood reefs area and the Hindon Antimony Mine, southeast of Middlemarch. Otago Schist, Waipiata Volcanics and quartz and sulphide reefs were mapped.
Five schist rock types are recognised on the basis of hand specimen observations. The study of schist rock types was undertaken to determine any relationship between textural zone 4 schist that is interlayered with massive unsegregated schist. Geochemical analysis revealed a chemical pattern similar to Wellington Torlesse. From this it is possible to relate the differences in massive and layered schist as a function of original grain size. Three phases of deformation are recognised in the schist.
Postmetamorphic emplacement of quartz sulphide reefs is recognised at Barewood, and the Antimony Mine. Five quartz reefs are mapped at Barewood which trend northwest at an angle to the regional schistosity.
Two phases of mineralisation are recognised. The first entails quartz sulphide mineralisation and the second is quartz scheelite mineralisation.
Fluid inclusion evidence suggests that the temperature of formation of the Antimony Mine is hotter than that at Barewood. On the basis of observations by previous workers and the fluid inclusion evidence it is suggested that the Barewood reefs and the Antimony Mine are related events. It is expected that Barewood contains massive antimony deposits at depth.
Five schist rock types are recognised on the basis of hand specimen observations. The study of schist rock types was undertaken to determine any relationship between textural zone 4 schist that is interlayered with massive unsegregated schist. Geochemical analysis revealed a chemical pattern similar to Wellington Torlesse. From this it is possible to relate the differences in massive and layered schist as a function of original grain size. Three phases of deformation are recognised in the schist.
Postmetamorphic emplacement of quartz sulphide reefs is recognised at Barewood, and the Antimony Mine. Five quartz reefs are mapped at Barewood which trend northwest at an angle to the regional schistosity.
Two phases of mineralisation are recognised. The first entails quartz sulphide mineralisation and the second is quartz scheelite mineralisation.
Fluid inclusion evidence suggests that the temperature of formation of the Antimony Mine is hotter than that at Barewood. On the basis of observations by previous workers and the fluid inclusion evidence it is suggested that the Barewood reefs and the Antimony Mine are related events. It is expected that Barewood contains massive antimony deposits at depth.
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Thesis description:
vii. 82 p. ill, photos, diagms, map (folded in pocket); 30 cm.
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OU geology Identifier:
1984Neehoff
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Location (WKT, WGS84):
POLYGON ((170.055748773887103 -45.73507291887362,170.057107286912981 -45.735107949717118,170.085289865673587 -45.742499305955434,170.112514002750686 -45.7422385479288,170.112170349147135 -45.748898134295544,170.067128021742633 -45.75156025909078,170.055748773887103 -45.73507291887362))
Collection
Citation
Neehoff, BA, “Geology of Barewood and the Antimony Mine.,” Otago Geology Theses, accessed December 7, 2024, https://theses.otagogeology.org.nz/items/show/179.