Alexandra Antimony Mine, Alexandra, Central Otago District, Otago Region, South Island, New Zealand
| Latitude & Longitude (WGS84): | 45° 15' 17'' South , 169° 22' 44'' East |
|---|---|
| Latitude & Longitude (decimal): | -45.25473,169.37902 |
| Köppen climate type: | Cfb : Temperate oceanic climate |
A vein of stibnite was exposed on the banks of the Clutha River, opposite the Alexandra town site, and 300 metres up river from the bridge.
It was known from the early days of the gold rush, but only investigated in 1900, by Blair and Miller (surnames) who sank a shallow shaft close to the river bank, and dug cross trenches.
The lode is a small north-east striking stibnite bearing lode. A collector reports on the site in 1974, being the early days of collecting when specimens were available. It is unclear the present status of the site, being close to urban development.
The site shows as a crumbly quartz vein in mica schist, trending north north-east, and dipping 45 degrees west north-west. The stibnite is found in short irregular bands. The workings were not accessible in 1974, and the mullock pile was dug over. Surface and near surface specimens were covered by a yellow oxide coating of cervantite, and rarer valentinite. Scraping away the coating reveals the metallic stibnite, lustrous, but dulls over the years when exposed. Only cleavage faces show, up to 4 cms.
(Watson, 1974) recommends finding a large chunk with quartz veins, which may contain cavities with stibnite crystals. Specimens are described where stibnite crystals alter course across the cavities to avoid quartz crystals.
Specimens of this quality still available at the site now is unlikely.
Mineral List
4 valid minerals.
Regional Geology
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
| Holocene 0 - 0.0117 Ma ID: 1369039 | OIS1 (Holocene) mining waste Age: Anthropocene (0 - 0.0117 Ma) Description: Well sorted sandy quartz, schist and sandstone gravels in dredge tailings and sluicing deposits; anthromorphic fossils. Comments: Holocene human-made deposits. Age based on known Lithology: Major:: {gravel},Minor:: {sand} Reference: Heron, D.W. . Geology Map of New Zealand 1:250 000. GNS Science Geological Map 1. [13] |
| Triassic 201.3 - 252.17 Ma ID: 1310831 | Caples Group TZIII schist Age: Triassic (201.3 - 252.17 Ma) Stratigraphic Name: Caples Group Description: Schistose (TZIII) volcaniclastic sandstone, siltstone, mudstone and conglomerate with included volcanics and limestone; minor quartzite, metachert and serpentinite. Comments: Eastern Province (Caples Terrane) Rocks Lithology: Limestone, quartzite, chert, serpentinite Reference: Edbrooke, S.W., Heron, D.W., Forsyth, P.J., Jongens, R. (compilers). Geology Map of New Zealand 1:1 000 000. GNS Science Geological Map 2. [12] |
| Triassic - Permian 201.3 - 298.9 Ma ID: 3189657 | Paleozoic-Mesozoic crystalline metamorphic rocks Age: Phanerozoic (201.3 - 298.9 Ma) Stratigraphic Name: Haast Schist Comments: Caples Terrane Lithology: Metawacke; greenschist/almandine amphibolite grade metasedimentary/metavolcanic schist Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. [154] |
Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License
References
