Based on the close proximity of the studied Fe-Cu ores to calc-alkaline Mirkani granitoids of the western Kohistan batholith
calc-silicate mineralogy, petrographic and trace element geochemistry of magnetite minerals, these deposits are classified as skarn-type hydrothermal deposits (Our study in progress).
Regional assessment of Marble and
calc-silicate rocks of Rajasthan.
The field occurrence of marbles in the Cienaga skarn reveals that they show a variable morphology (with sharp contacts) and thickness with a transition into carbonate-silicate rocks, which consecutively pass into
calc-silicate and carbonate-bearing silicate rocks.
The host rock is strongly altered, comprising coarse garnet and magnetite.This strong
calc-silicate alteration, that includes garnet, has proven to be a good indicator of base metal mineralisation at Jervois, suggesting close proximity to mineralisation.
According to the company, although graphite has been identified locally in marbles, graphite is also hosted here in quartz, biotite/mica gneisses and in
calc-silicate gneisses.
If the protolith is siliceous carbonate, then
calc-silicate minerals will be part of the mineral paragenesis.
Analcime has been found in
calc-silicate skarn at FPS and other contact skarn deposits, as well as in granitic pegmatite and nepheline ([+ or -] corundum) syenite.
the more variegated gneiss complex with intercalations of
calc-silicate rocks, marbles, amphibolites and orthogneisses (Varied group).
Croix terrane contain similar lithological successions comprising quartzite, quartzite-pebble conglomerate,
calc-silicate rocks, quartzo-feldspathic wacke, grey shale and coticule-bearing sandstone.
But impure marbles (containing silicate and
calc-silicate minerals) can be challenging to slab and polish, especially if the impurities occur as patches rather than being finely disseminated.