Sustainable Mineral Resources Supply: Challenges for Future Generations, Geneve, Switzerland, 13 - 16 September 2022, pp.32-33
Niğde Massif (South-central Turkey) is a metamorphic core complex composed of a
migmatite-paragneiss basement, overlain by schist-marble-amphibolite alternation and a thick
marble sequence. The massif experienced peak pressure-temperature conditions of >725 ℃
and ∼16-20 km at the age of ∼ 91 Ma, which led to the partial melting of continental crust
and generation of a subsequent intrusion of the crustal-derived Üçkapılı Granite and dike/sill
arrays into the massif.
The field studies led to three distinct mineralization sites: (i) along the low-angle faults
at schist-marble contacts, (ii) within the high-angle cataclastic shear zones in schist layers, and
(iii) in between the foliation planes of schists.
A common association of intrusive bodies with mineralized shear zones implies that
intrusion might have played a role in transporting or remobilizing the ore via a hydrothermal
fluid. Discrete shear zones and associated foliation planes are used as fluid pathways and hosts.
Structural relationships between brittle and ductile structures and the Au-Hg-As-Sb-Pb
paragenesis indicate that these deposits can be classified as orogenic gold deposits. However,
considering that these deposits are accumulated during the exhumation of the metamorphic
units, the absence of meso/macro scale mineralized quartz veins/veinlets contradicts the
classical models proposed for the development of the Precambrian orogenic gold deposits.