Kai Point Mine, Kaitangata, Clutha District, Otago Region, South Island, New Zealand

Latitude & Longitude (WGS84):	46° 16' 18'' South , 169° 52' 42'' East
Latitude & Longitude (decimal):	-46.27173,169.87857
Köppen climate type:	Cfb : Temperate oceanic climate

Active coal mine.

The mine opened in 1958 by George Cross, producing 55 000 tonnes of coal per annum. The Kaituna seam is mined, and early in the mine's history the overlaying Barclay seam was mined. The mine is one of the best sources in New Zealand for late Cretaceous plant fossils.

The basement rocks are geosynclinal sediments and chlorite schists many thousands of feet thick, overlain with greywacke conglomerate called the Henley Breccia, overlain by the Taratu Formation of coal measures. Overlying this is the Wangaloa Formation consisting of quartz pebble conglomerate, kaolinized sandstone, siltstone, mudstone, with Paleocene marine fossils. The sandstone layers have spherical concretions up to 10 cms across cemented by pyrite. The siltstone and mudstone layers contain ellipsoidal concretions up to one metre across cemented with ankerite.

The Taratu Formation is dominated by quartz rich sediments of quartz and greywacke pebble conglomerate, within a kaolinite matrix, kaolinite rich siltstone, and mudstone, with numerous coal seams. The formation is up to 1500 metres thick, although only the top 750 metres has been studied. The formation contains thirteen known coal seams, but only the Kaituna and Barclay seams have been mined, 3-8 metres thick, sometimes up to 15 metres thick of sub-bituminous coal, with some mudstone partings. They grade laterally into mudstone, or are truncated abruptly by quartzose pebbly sandstone and conglomerate. Thin coal seams are overlain by sandy conglomerate, and thicker seam by mudstone. Coal grades from lignite A to sub-bituminous C.

Remobilisation of pyrite by groundwater, has resulted in pyrite seams up to 5cms thick in the coal seams, and within 2 metres above in the Wangaloa Formation. The mine is capped by a 1-4 metre thick Pleistocene veneer of loess siltstone, and colluvium derived from the siltstone.

Mineral List

4 valid minerals.

Rock Types Recorded

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

Priabonian - Campanian 33.9 - 83.6 Ma ID: 1319693	Taratu Formation (Onekakara Group) Age: Phanerozoic (33.9 - 83.6 Ma) Stratigraphic Name: Taratu Formation Description: Non-marine quartz pebble conglomerate (locally silica-cemented) sandstone, siltstone, mudstone and coal. Comments: Late Cretaceous - Paleogene sedimentary rocks. Age based on palynology Lithology: Major:: {sandstone},Minor:: {mudstone, siltstone, conglomerate, coal} Reference: Heron, D.W. . Geology Map of New Zealand 1:250 000. GNS Science Geological Map 1. [13]
Eocene - Late Cretaceous 33.9 - 100.5 Ma ID: 1313231	Onekakara Group and Taratu Formation Age: Phanerozoic (33.9 - 100.5 Ma) Stratigraphic Name: Onekakara Group; Taratu Formation Description: Quartz conglomerate, sandstone, siltstone, mudstone and coal seams. Comments: Zealandia Megasequence Terrestrial and Shallow Marine Sedimentary Rocks (Paleogene to Cretaceous) Lithology: Conglomerate, sandstone, siltstone, mudstone, coal 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

External Links