Sorry if this post is repeated, the one I did earlier seemed to vanish even though I psted it.
Anyway - Mining in exturusive igneous rocks, i.e. the rock in volcanically formed places such as the canary islands or Hawaii seems to be quite a rarety, at least for mineral mining - although the quarring of basalt often takes place; as well as the underground search for water by driving adits, though I'm uncertain as to whether this actually counts as mining; any advance on this?

Anyway - I'm interested in what minerals, if any at all are mined in "recent" volcanic rock, so any contributes to the pst would be appriciated, and of interest.

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Well diamonds are formed deep underground but are brought to the surface by volcanic activity to allow open pit mining but I have a feeling you don't mean that.

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Sorry if this post is repeated, the one I did earlier seemed to vanish even though I psted it.
Anyway - Mining in exturusive igneous rocks, i.e. the rock in volcanically formed places such as the canary islands or Hawaii seems to be quite a rarety, at least for mineral mining - although the quarring of basalt often takes place; as well as the underground search for water by driving adits, though I'm uncertain as to whether this actually counts as mining; any advance on this?

Anyway - I'm interested in what minerals, if any at all are mined in "recent" volcanic rock, so any contributes to the pst would be appriciated, and of interest.

Have been thinking about your post and in the process dug out a couple of OU books that I’d saved. Now of course I have a raging headache. Anyway one of them is about ore deposits with a chapter on ore deposits formed by igneous processes. The chapter starts thus:
“Volcanoes are the most striking products of igneous processes; they are noted for their spectacular fountains of fiery lava and potentially devastating ash clouds. They are the result of magma escaping at the earth’s surface, where it cools rapidly so that the igneous fractionation processes (also known as differentiation processes) have no chance to operate or ore deposits to form.”
It then goes on to explain in detail the different processes, hence the headache. It would seem from this that places like Hawaii, formed when the tectonic plate slid over a ‘hot spot’ in the mantle or any rock of volcanic origin cannot contain ore deposits, therefore no mining.

Edit
Should have said no mining apart from rock.

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You sometimes get sulphur mining in association with active or recently extinct volcanic activity.

There is no reason why basalt can't host ore deposits too, in the same way that sandstones and limestones can but not when its 'fresh' for the reason Carnkie gives.

Granites are of course intrusive rather than extrusive rocks, but formed by volcanic processes and do host useful deposits as formed. Pegmatites are the last fraction of the rock to solidify and can contain concentrations of unusual elements such as molybdenum, berylium etc. They are, however formed at depth so aren't mined until there has been considerable erosion of the ground surface.

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A summary of ore deposits formed by igneous processes

Igneous processes take place in magmatic systems, and involve crystals, immiscible liquids (magma, sulphide melt, oxide melt, water), and gases (as formed when water boils). Chemical and physical processes associated with the separation of crystals or immiscible liquids from magma, give rise to magmatic fractionation, which can produce a range of igneous rock types and may concentrate metals to form ore deposits.

Igneous rocks span a range of compositions — from peridotite to gabbro (basalt) to diorite (andesite) to granite (rhyolite)—the formation of which depend on the source of the magma and the extent to which magmatic fractionation has occurred. Different types of ore deposit are associated with particular types of igneous rocks: magmatic segregation deposits are associated with peridotites and gabbros, pegmatite ore deposits with granites, and porphyry ore deposits with diorites, granodiorites and granites.

Magmatic segregation deposits separate from hot fluid basaltic magmas when either dense early-formed crystals, or dense immiscible liquids (sulphide or oxide), sink towards the floor of a magma chamber and form cumulate layers. Settling of crystals may produce chromite and magnetite ore deposits; settling of sulphide-rich immiscible liquids may produce ore deposits rich in copper, nickel, gold or platinum; settling of oxide-rich immiscible liquids may produce ore deposits rich in iron or iron-titanium oxides. Development of the multiple layering that is typical of many magmatic segregation deposits requires periodic influxes of magma into the magma chamber.

Pegmatites form from granitic magma after anhydrous minerals have crystallized from it, so enriching the remaining melt in water and sometimes incompatible elements, and thus making it particularly fluid. Pegmatites are not often mineralized, but when they are, they can be enriched in valuable metals, including beryllium, caesium, lithium, niobium, rare earth elements (such as cerium), tantalum, thorium, tin, tungsten, uranium and zirconium, many of which rarely form mineral deposits in other circumstances.

Porphyry deposits are formed when metal-rich watery fluids boil and are released explosively from a wet granodioritic magma being emplaced at a high level in the crust. The network of fractures produced, provides pathways for distribution of metal-rich fluids that were derived initially from the magma and subsequently from surrounding rocks. The fractures also provide sites for the deposition of ore minerals, as fluids cool and react with wall rocks. Porphyry deposits provide much of the world's copper and molybdenum, as well as substantial quantities of tin, silver and gold as by-products. They are typically low-grade but extremely large deposits. The Chilean porphyry copper belt and Chuquicamata copper mine - the largest copper producer in the world, being an obvious example.

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In addition to sulphur formed around fumarolic vents you can add a number of epithermal gold (and silver) deposits that form in the near surface environment (up to the water-table). Some of these can be quite recent (in the last 1Ma) and precious metal systems are seen at the present day in New Zealand depositing gold in the near surface environment within tuffs and ashes.

Of course you have several industrial minerals mined from such lithologies such as perlite, pumice, bentonite, zeolite etc etc.

Many thanks for all the detailed replies folks 😃, I had an impression that sulpher might have been mined, very interesting stuff, especially so because the rock mined is often very young, quite often less than 1 million years, whereas Britain's rocks are generally up in the hudreds.

I suppose that in theory - minerals that have deposited outside/in openings in the ground on volcanoes (most often sulpher) could be mined/taken off the rocks (Provided it was cool enough..)

Still seems that little mining in these regions does go on, I did internet searches for mining in the canary islands and mining in Hawaii, to find nothing really

😞

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Sulphur and other volatile minerals tend to vapourise with the heat and escape into the atmosphere when extruded onto the surface.
This type of deposit usually form as an intrusive type where the host rock prevents it from escaping. The minerals can be remobilised as fumes or in hot aqua solutions and form a deposit near the surface.

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Another area where you get complex systems and mineral deposits are Ocean Ridge Hydrothermal Vents. Copper and iron - sulphides and zinc sulphides.

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Sulphur and other volatile minerals tend to vapourise with the heat and escape into the atmosphere when extruded onto the surface.

And this has a great effect on the world's climate when there are major volcanic eruptions. The sulpher compounds, oxide and dioxide rise high into the atmosphere and combine with water droplets to form sulphuric acid droplets. These reflect sunlight and can cause global cooling for two or three years. The Tambora eruption in 1815 caused a .5-.7 drop in global temps (a massive drop) and 1815 was known as the year without a summer. It snowed in London in August. :oops: :offtopic:

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The issue in the Canary Islands and Hawaii is the nature of the volcanic rocks - such mid-Ocean seamount basalts are not associated with metallic mineral deposits (or indeed many non-metallic deposits)

Just a little more about mining on the sea bed. One example. In certain places on the deep-ocean floor (4000-5000 m deep), where the rate of sedimentation is extremely slow, the sea bed is carpeted with small potentially mineable manganese modules the size and shape of potatoes or tennis balls. There is little interest in their manganese content; the attractive feature is their high content of combined copper, nickel, and cobalt (averaging 2.4% in places). In shallower waters (around 1000-2000m), the flanks of volcanic islands (Hawaii?) and seamounts may be encrusted with manganese oxides that are particularly rich in cobalt. Constraints on utilising these various deposits include the high cost of mining in deep water, the variability of ore grades, the distance to market, and the competing costs of mining on land.
Despite this the constraints have not stopped international consortia of companies from Japan, the UK, France, Germany, and the US, and the Indian Government from exploring for manganese nodules and/or developing the means to harvest them.

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