Geology of the Brown peak - Clare peak area, Northern Takitimu mountains, Western Southland, New Zealand.
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Abstract:
The Permian rocks (Takitimu Group) of the Brown PeakGlare Peak area are part of the Brook Street Terrain which crops out along the western side of the deformed New Zealand geosyncline.
A geological map of the area and representative stratigraphic columns have been made.
The Takitimu Group in the area (Brown Peak Formation and Challis Peak Beds) consists of a 2.5 kilometre thick sequence of faulted, gentle dipping, volcanogenic sediments of andesitic and basaltic composition. The sedimentary rocks are described and their provenance related to a marginal arc trench basin which evolved along a submerged linear volcanic chain. A fossil assemblage suggests that the Brown Peak Formation is of upper Sakmarian to lower Artinskian age.
At least two suites of igneous rocks intrude the Takitimu Group. Phase l intrusives (diorite, microdiorite and dolerite sills and dykes) cut sediments and in turn are intruded by phase 2 intrusives (andesitic and basaltic sills, dykes and plugs).
Both the sedimentary and phase l intrusive rocks have adjusted to the metamorphic conditions of the prehnitepumpellyite facies. The metamorphic alteration of a dolerite sill (phase l intrusion) is studied in detail. The bulk of metamorphism appears to have occurred before th~ end of the Permian.
Tertiary sediments which crop out along the eastern boundary of the study area are briefly described.
A geological map of the area and representative stratigraphic columns have been made.
The Takitimu Group in the area (Brown Peak Formation and Challis Peak Beds) consists of a 2.5 kilometre thick sequence of faulted, gentle dipping, volcanogenic sediments of andesitic and basaltic composition. The sedimentary rocks are described and their provenance related to a marginal arc trench basin which evolved along a submerged linear volcanic chain. A fossil assemblage suggests that the Brown Peak Formation is of upper Sakmarian to lower Artinskian age.
At least two suites of igneous rocks intrude the Takitimu Group. Phase l intrusives (diorite, microdiorite and dolerite sills and dykes) cut sediments and in turn are intruded by phase 2 intrusives (andesitic and basaltic sills, dykes and plugs).
Both the sedimentary and phase l intrusive rocks have adjusted to the metamorphic conditions of the prehnitepumpellyite facies. The metamorphic alteration of a dolerite sill (phase l intrusion) is studied in detail. The bulk of metamorphism appears to have occurred before th~ end of the Permian.
Tertiary sediments which crop out along the eastern boundary of the study area are briefly described.
Thesis description:
114 p. : illus., (part col.), maps (1 col. in pocket) ; 30 cm.
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1975Pringle
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Location (WKT, WGS84):
POLYGON ((167.955853894000029 -45.643645509999942,167.943100910000112 -45.643093910999937,167.911629688000062 -45.641722054999946,167.883728449000046 -45.640502501999947,167.886075649000077 -45.614531750999959,167.886561436000079 -45.609143567999979,167.896302283000068 -45.609570092999945,167.913918976000105 -45.610343856999975,167.913117010000065 -45.621330488999945,167.936578823000104 -45.622301123999932,167.942833557000085 -45.615098499999931,167.958307163000086 -45.615903159999959,167.955853894000029 -45.643645509999942))
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Citation
Pringle, Ian James., “Geology of the Brown peak - Clare peak area, Northern Takitimu mountains, Western Southland, New Zealand.,” Otago Geology Theses, accessed February 10, 2026, https://theses.otagogeology.org.nz/items/show/88.