Maerewhenua diggings, Waitaki District, Otago Region, South Island, New Zealand
| Latitude & Longitude (WGS84): | 44° 56' 8'' South , 170° 34' 27'' East |
|---|---|
| Latitude & Longitude (decimal): | -44.93579,170.57424 |
| Köppen climate type: | Cfb : Temperate oceanic climate |
Gold found in alluvial gravels.
The Maerewhenua diggings are found ten kilometres south of Duntroon, on the western side of the Maerewhenua valley, particularly around Pringles Gully. Gold was discovered in the area in 1865 by Thomas Harrison, James Spence, and Thomas Elliot, stone masons and part time gold prospectors. It was never a rich field, with at most seventy miners scratching a living, across two or three gullies along the western side of the valley. The Livingstone diggings are a short distance to the south.
Fine gold is found in glauconitic sand, and quartz gravels. The gold is fine and scaly, however in the river was found shotty coarse gold, and gold attached to quartz.
The main issue with these diggings, is they acted as a lightning rod for the wider environmental concerns related to hydro sluicing (and dredging) on river water quality. Water races would bring water into the diggings, which were then funnelled into jet nozzles to blast the gravel, sending it through sluice boxes to trap the gold. The barren sludge was then dumped into the nearest waterway, in this case the Maerewhenua River.
There was little interest at the time in protecting pristine waterways, for their own intrinsic value, natural resources purely looked at as a way to make money. However, if the actions of miners, prevented someone else from making a living, that was another matter altogether.
The Maerewhenua River winds lazily down from the Kakanui Mountains until it joins the Waitaki River at Duntroon. The dumping of large amounts of sludge caused the river to become blocked, overflowing its banks, and spreading silt across paddocks, making them unproductive.
Local farmers, Borton and McMaster took the miners to the Supreme Court in 1874, finding in their favour. Unthinkable today, local papers championed the miners, arguing the dumping of sludge merely discoloured the water. The miners they stated had a right to be sluicing, with the area a declared goldfield, and the actions of a few greedy farmers endangered the viability of gold mining across the whole country. Sludge dumping continued, and the chastened farmers were left to bear the brunt of poor quality water for their stock, and floods covering their paddocks with silt.
By 1890, the level of the river bed had risen 4 feet, with flooding every winter resulting in homesteads and farms having to be abandoned. The farmers went to court again (Borton V Howe). Meanwhile the miners association petitioned the government, to declare the river officially a sludge channel, which it did in 1892. The farmers were given some monetary compensation.
By 1919, this sludge menace was now threatening to destroy road bridges, railway lines, and the domestic water supply for Oamaru, with major engineering works being touted to resolve. While little mining was now taking place, the commission of inquiry toured the barren wasteland of the diggings, desolate former paddocks, abandoned homesteads, and a river full to the brim of silt. The papers now ran the line, who could have known back in 1892, that dumping vast quantities of muck into a river could have such an effect, which seems short sighted, even by the standards of the day.
It is ironic major discussions are happening in New Zealand at the moment over the effect of dairying on the quality of river water. A few years ago the Maerewhenua River was pegged for modern dredging. This involves a $20 000 mini dredging pontoon, and a diver. It caused an outcry amongst trout fishing groups(an introduced fish), and those who wish for free range gold extraction for anyone, neither necessarily environmentally friendly to rivers. Few would know the argument is an old one.
Mineral List
1 valid mineral.
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 - Ypresian 33.9 - 56 Ma ID: 1365953 | Taratu Formation (Onekakara Group) Age: Eocene (33.9 - 56 Ma) Stratigraphic Name: Onekakara Group; Taratu Formation Description: Non-marine quartz sand and conglomerate with clay matrix, lignite seams and carbonaceous mudstone, limonite and silica cemented. Comments: Late Cretaceous - Paleogene sedimentary rocks. Age based on paleontology Lithology: Major:: {sandstone},Minor:: {conglomerate} 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: 1313093 | Onekakara Group and Taratu Formation Age: Phanerozoic (33.9 - 100.5 Ma) Stratigraphic Name: Haerenga Supergroup; Onekakara Group; Onekakara Group and 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] |
Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License
References
