Magmatic Ore Deposits - Metals and Society: An Introduction to Economic Geology - page 67

Table 3.3 Other types of magmatic ore deposits
Commodity Rock type Geological setting Examples

Tin Granite As a magmatic mineral

(cassiterite) within
granitic plutons and
along margins where
late magmatic fluids
have interacted with
country rocks
(greissen)

Tin granites of
Malaysia,
Australia, Brazil

Iron, titanium,
vanadium

Gabbroic and
anorthositic
intrusions

Ti-V-bearing magnetite
occurs as a cumulus
phase in gabbroic
intrusions; large
ilmenite deposits occur
in Proterozoic
anorthosite massifs

Fe-Ti-V: Bushveld,
South Africa;
Panzhihua, China
Ilmenite: Tellnes,
Norway; Allard
Lake, Canada

Rossing, Namibia

Uranium Leucogranite Disseminated uraninite in

leucogranite dykes

Lithium, beryllium,
tin, tantalum,
niobium, etc.

Pegmatite Magmatic minerals in

aqueous fluids released
at the end stage of
crystallization of
granitic magma

Wodgina and
Greenbushes,
Australia: Bernic
Lake, Canada;
Marropino,
Mozambique

Cu Zr, Ti, U,
magnetite,
vermiculite

Carbonatite A carbonatite pipe in a

alkaline pyroxentitic
intrusion

Palabora, South Africa

Rare earth elements,
Nb, Ta

Carbonatite The REE occur in

bastnasite, (Ce,La,
Nd,

Mountain Pass, USA;
Bayan Obo,
Mongolia ).CO 3 F, in

carbonatite intrusions

...

Diamond Kimberlite,

lamproite

Diatremes in Precambrian
cratons

Numerous deposits in
Botswana, Russia,
Congo, South
Africa, Canada,
Australia

surprising because we have no entirely convincing model to explain the anorthosite
massifs themselves.
Yet another type of magmatic ore deposit is found in pegmatites and
carbonatites, from which metals like Li Be, B, Sn, Nb, Ta and the rare earth
elements are mined. In this type of geological setting, little question surrounds
the geochemical grounding for the association between metal and host rock. The
metals in question are highly incompatible (i.e. they cannot be accommodated in
the crystal lattices of common silicate minerals) and for this reason they become
concentrated in highly evolved aqueous silicate liquids (e.g. pegmatite) or in the
products of low-degree melting of the mantle (e.g. carbonatite). Deposits in
pegmatites and carbonatites are generally small, but with accelerating industrial