Alluvial gold mining in Otago, Gold in Otago, Department ...
Alluvial mining is technically simpler than hard-rock mining, so alluvial mining dominated Otagos gold mining history. Alluvial gold occurs as loose particles in the gravel, and is therefore easy to separate because of the high density of the gold. Many of the earliest alluvial mines were extremely rich (10s or even 100s of grams of gold per tonne of gravel), but most gravels had at most a few grams of …
Alluvial gold along the northeast Otago margin, Geology ...
The Blue Lake alluvial gold mine, St Bathans, Central Otago. The Blue Lake Fault passes through this area, but is diffuse as it has caused shearing at several different rock boundaries. Gold was enriched near the boundary between the white quartz gravels (centre) and the greywacke basement that forms the hills to the right and in the background.
Hard-rock gold mining in Otago, Gold in Otago, Department ...
Historically, hard-rock mining was a minor part of the gold mining industry in Otago because it is a very capital-intensive process. First the quartz had to be blasted from the bedrock schist, in tunnels of underground mines. Ore was crushed in water to a fine slurry in large stamping batteries. The gold liberated at this stage was then dissolved in mercury or cyanide and extracted.
Patearoa gold: Alluvial concentrations in a dynamic ...
The Macraes deposit contains at least 9 million ounces of gold, more than the historical alluvial gold production from Otago. Erosion of the Macraes deposit, and other similar deposits, released gold grains into rivers that transported the gold all over Otago.
Environmental aspects of mining gold in Otago, Gold in ...
Gold in Otago 1. Island Block alluvial gold mine (near Roxburgh) after rehabilitation. The mine was developed in an old channel of the Clutha River (flats in foreground) which was abandoned thousands of …
Gold Mining Central Otago, NZ | Central Otago, New Zealand
Central Otago rivers were rich with gold and the focus of the early alluvial mining of river flats and shallows during the first rush in the early 1860s. Dredging (1880s–1920s) ploughed the riverbeds and eventually the inland terraces and beyond and is responsible for most of the altered landscapes.
otago gold alluvial mining - communales2018.be
Alluvial gold mining in Otago, Gold in Otago, Department The gold wires enclosed lumps of schist and clay from the soil as they grew. Alluvial mining is technically simpler than hardrock mining help
Gold, Department of Geology, University of Otago, New Zealand
Alluvial gold along the northeast Otago margin; Rise of modern mountains on Otago’s northeast margin; Patearoa gold: Alluvial concentrations in a dynamic environment; Gold Cycle - Gold from the mountains to the sea. Gold occurs in thin veins of white quartz near the crest of the Southern Alps. It is transported in rivers and deposited near the sea. The action of the sea concentrates the gold in beach sands. Gold …
Economies of Scale (gold in Otago), Gold in Otago ...
The total reported historical alluvial gold production from Otago was about 240 tonnes but undeclared gold could make this a very much higher figure. Hard-rock mining was on a small scale only, and most mines consisted of a few hundred metres of tunnels and a stamping battery.
Otago Gold Rush - Wikipedia
Although they found alluvial gold, there were no large deposits. The West Coast of the South Island was the second-richest gold-bearing area of New Zealand after Otago, and gold was discovered in 1865-6 at Okarito, Bruce Bay, around Charleston and along the Grey River. Miners were attracted from Victoria, Australia where the gold rush was near an end. In 1867 this boom also began to decline, though gold …
Otago – Te Ara Encyclopedia of New Zealand
Historically in Otago the majority of recovered gold was alluvial – less than 10% came from hard rock. Otago’s gold is linked to its schist rocks. Over the past 100,000 years glaciers ground away at the rocks, which were threaded with quartz veins containing gold, and rivers washed and sorted the gravels.
Bannockburn, New Zealand - Wikipedia
Ngāi Tahu Bannockburn is a small historic gold mining town located outside of Cromwell in Central Otago, New Zealand. The area was first made known as a rich alluvial gold field and was mined extensively in the 1860s.
GOLD RUSH AND GOLD MINING: A TECHNOLOGICAL …
historians of the Otago gold rushes and gold mining may be encouraged to pursue other lines of enquiry with the role of technology included in their perspective.
Gold and gold mining - teara.govt.nz
The early mining of the 1860s in Otago and on the West Coast was mainly undertaken by individuals working alluvial deposits (river gravels). In three separate years in the late 1860s and early 1870s the amount of gold won exceeded 20,000 kilograms. These totals have never been bettered.
Alluvial gold mine approved | Otago Daily Times Online News
Aug 23, 2016 · Theres no need to travel to Rio to win gold, as a large-scale alluvial mining operation near Roxburgh has got resource consent. However, opposing neighbours may appeal. Independent commissioners yesterday released a decision allowing Kokiri Lime Company Ltd to mine on 163ha of land at Coal Creek Flat now used for pastoral farming and horticulture.
Gold and gold mining – Te Ara Encyclopedia of New Zealand
Alluvial gold comes from the rocks once they have been worn down to sand and gravel over many thousands of years by rivers or glaciers. The gold lies in the gravel of river beds and can be sifted by hand using a pan, sluiced, dredged, or dug up with machines.
Public Gold Fossicking Areas - New Zealand Gold ...
Alluvial gold is present within all these gold fossicking areas, although the concentrations are often low. All these areas are suitable for gold panning and sluice boxing, mining being restricted to hand-held non-motorised methods within the active stream bed. Nelson-Marlborough and the West Coast Aorere River - …
Gold fossicking - New Zealand Petroleum and Minerals
Panning for gold. Gold mining normally requires a permit from NZP&M, however 19 areas in historic South Island gold mining regions have been set aside – in Nelson-Marlborough, the West Coast and South and Central Otago - where you can freely enjoy recreational gold mining without the need for a …