Genesis

Gold deposition is inferred to have occurred during a major period of strike-slip movement and terrestrial basin formation that spanned the Late Permian and Early Triassic. The event is marked by a profound change in sedimentary depositional environments from a marine carbonate shelf-type sedimentation in the Late Palaeozoic to non-marine terrigenous, saline to hypersaline depositional settings in the Jurassic and Cretaceous characterized by the "red-beds" of Cover Sequence 2 (Syr Daria Basin). This change can be observed through much of Central Asia.

Mineralisation was emplaced within the pre-existing metamorphic aureole of a buried Permo-Carboniferous felsic intrusive. Isotopic data indicate that mineralisation occurred about 30 million years later than cooling of the intrusion below its Rb-Sr closure temperature (Kostitsyn, 1996). The intrusion and its metamorphic aureole probably controlled the subsequent development of the ore-forming hydrothermal cell because of the permeability variation imposed on the host succession by the intrusion and its metamorphic halo. The aureole and the intrusive could have acted as a brittle and dilatant block, generating a more strongly fractured zone containing more dilatant fractures than the adjacent more ductile host-rocks. It is not clear however, if the intrusion could have remained a source of a thermal anomaly focussing a hydrothermal cell for over 50 million years after emplacement.