DILL,
H.G (1998): Evolution of Sb mineralisation in modern fold belts: Comparison of
the Sb mineralisation in the Central Andes (Bolivia) and the Western
Carpathians (Slovakia).- Mineralium Deposita, 33:
359-378; Berlin.
Abstract: In the Central Andes (Bolivia) and the Western
Carpathians (Slovakia) Sb-(Au) deposits are of widespread occurrence. They may
be subdivided into two principal types: (I) shear zone-hosted and (II) stockwork-like
Sb deposits. Type I Sb deposits are widespread in fine-grained metasedimentary,
granitic and gneissic rocks. Type II is only found in volcanic rocks and may be
further subdivided into acid sulphate-type (IIa) and low sulphidation-type
(IIb). This more subtle classification is based upon the presence or absence
of sulphate and K feldspar and applied in the same way as for epithermal Au
deposits elsewhere. Type III is a composite vein type transitional between
types I and II Sb deposits. Mesothermal deposits (type I) were emplaced syntectonically
and synmetamorphically under low grade to very low grade stage metamorphic
conditions. The mineralising fluids are likely to have been derived from
crustal sources through devolatalisation. Epithermal types (IIa) and (Ilb) are
related in time and space with the formation of acidic to intermediate
(sub)volcanic rocks of Miocene age. To distinguish the various types of Sb
mineralisation, Bi, Ag, As and Hg have proven most diagnostic. These elements
are anomalously enriched in the volcanic-hosted types IIa and Ilb, whereas type
I mineralisation are poor in Bi, Ag and As. The element contents of these trace
elements in type III deposits vary according to the position of the host
mineralisation relative to the Tertiary igneous rocks. Mercury tends to be enriched
in type II mineralisations. Even so there are also some Sb mineralisations of
type I abundant in Hg, possibly due to tetrahedrite intergrown with stibnite.
In contrast to porphyry copper deposits, stibnite deposits are distal relative
to the subduction zone. They are confined to sections of the fold belt where
the continental crust is thick and was subject to strong horizontal
displacement.