Gold and Other Minerals
Before the Atlantic Ocean opened, the Falklands were joined to South Africa along the margin of the Gondwana supercontinent.
There are striking geological similarities between Falklands geology and South Africa’s Cape Fold Belt and Karoo Basin, and this has led to speculation that the Falklands might contain mineral deposits of the same style as the well-known, world-class African examples.
Gold grains have been panned from a number of Falklands streams, and fresh, angular gold grains have been discovered, suggesting that the grains have not traveled far from their bedrock source.
Over 300 gold grains have been independently analysed by BGS, confirming three potentially different gold sources:
- a pyritic Black Shale source
- two separate epithermal sources in unknown host rocks.
A comprehensive gold exploration programme was conducted in the early to mid 2000s by Falklands Gold and Minerals Ltd. They acquired an extensive aeromagnetic survey of the Islands, and subsequently drilled and cored many of the identified geophysical anomalies. However, they failed to locate any potentially viable gold deposits, and the company relinquished its exploration licence in 2008.
Recent exploration found some possible diamond-indicator minerals such as chromite and garnet, although there is no evidence that the chemistry of these minerals is indicative of an origin in a kimberlite pipe.
Garnet and rutile grains are concentrated in features such as raised beach deposits. These could potentially form extractable mineral deposits, but are at present considered to be uneconomic due to the geographical isolation of the Falklands.
On some northern beaches, collections of agate pebbles can be found, refered to as 'Falklands Pebbles'. They are silca that has acculiated in the cavaties left behind when gas escaped from volcanic lavas. The agets are much harder than the surrounding lava and thus survive long after the host rock has vanished. The source could be vanished acient lava flows or perhaps a source deep in the ocean that was up to the north due to currents.