Isotopic (Nd, Sr, and δ~(18)O) Signatures of the Late Miocene High Sr-Ba Granitoids in the Mineral'nye Vody Area, Northern Caucasus: Evidence of the Protolith Nature

摘要

Felsic hypabyssal intrusions of the Caucasian Mineral'nye Vody or Minvody (CMV) area, one of the earliest manifestations of postcollisional magmatism in the Caucasian-Anatolian region, were emplaced in the Late Miocene about 8.3 Ma ago [1]. Laccoliths of the CMV area form a compact group over a small territory and consist of high Sr-Ba (latite) and Li-F granitoids [2], whose origin is still a matter of debate [3, 4]. Exposed granitoids form a ringlike structure, which is well expressed in the gravity and magnetic fields [5]. Rocks within the structure show zoned distribution, with syenites and granosyenites in the outer zone and intrusions of amphibole granites and leucogranites in the core (Fig. 1).