The Koshmansai ore field is located in the southern
part of the granitoid Chatkal batholith, in its apical ledge
and exocontact zones, in the Koshmansai river basin. The
host environment of the granitoids is Lower Carboniferous
carbonate rocks, which were primarily affected by
intensive skarnification. Sedimentary-metamorphic and
volcanics rocks and granitoids constitute the geological
structure of the skarn rare-metal-polymetallic Koshmansai
deposit.
In the distribution of ore-forming and associated elе-
ments in the mineral phases of skarn orebodies, their
morphogenetic type plays a certain role. Thus, in bimetasomatic
skarns, minerals accumulate more Cu, Zn,
Ni, Te, Tl, Ge. In infiltration skarns, these are Ag, Pb, Bi,
Cd, Sb, Co. Sulfide polymetallic mineralization in skarns
is associated with quartz and calcite.
The Koshmansai ore field has a distinct geochemical
zoning, which can be subdivided into the Koshmansai rare-
metal-polymetallic deposit at the upper levels of the
ore field and the Nizhnekoshmansai rare-metal-copper
ore occurrence at its lower levels. Nevertheless, orebodies
formation proceeded in a similar thermodynamic
environment, in the conditions of upper shielding at low
temperature gradients, which makes it possible to consider
the ore field as a single geochemical anomaly. The
vertical geochemical zoning of ore-forming element halos
determined by their concentration at the lower section
levels of the Koshmansai deposit skarn orebodies suggests
the expansion of its prospects in depth.
