Metasedimentary, granitoid, and gabbroic rocks from central Stewart Island, New Zealand
| Autor: | A. J. Tulloch, A. H. Allibone |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | New Zealand Journal of Geology and Geophysics. 40:53-68 |
| ISSN: | 1175-8791 0028-8306 |
| Popis: | A NNE—NE trending strip, 3–8 km wide, extending from the Freshwater valley across Mt Rakeahua, Table Hill, and Mt Allen to the northern end of the Tin Range was mapped at a scale of 1:12 500 to locate and investigate the boundary between the Median Tectonic Zone (MTZ) and Western Province on Stewart Island. A NNE‐trending fault, herein termed the Escarpment Fault, separates predominantly ductily deformed rocks on its south side from essentially undeformed rocks to the north. North of the Escarpment Fault, a small (2–3 km2) pluton of alkali‐feldspar granite (Freds Camp) intrudes gabbroic rocks tentatively considered to be associated with gabbro/ anorthosite/diorite of the Rakeahua pluton, centred on Mt Rakeahua. Both units were subsequently intruded by I‐type biotite granite of the South West Arm pluton. South of the Escarpment Fault the oldest intrusions are biotite tonalite‐granite orthogneisses (Ridge and Table Hill plutons) intercalated with the sillimanite‐cordierite‐bearing Pegasus Group met... |
| Databáze: | OpenAIRE |
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