Paleozoic–Mesozoic Porphyry Cu(Mo) and Mo(Cu) Deposits within the Southern Margin of the Siberian Craton: Geochemistry, Geochronology, and Petrogenesis (a Review)

Abstract

Abstract:The southern margin of the Siberian craton hosts numerous Cu(Mo) and Mo(Cu) porphyry deposits. This review provides the first comprehensive set of geological characteristics, geochronological data, petrochemistry, and Sr-Nd isotopic data of representative porphyry Cu(Mo) and Mo(Cu) deposits within the southern margin of the Siberian craton and discusses the igneous processes that controlled the evolution of these magmatic systems related to mineralization. Geochronological data show that these porphyry deposits have an eastward-younging trend evolving from the Early Paleozoic to Middle Mesozoic. The western part of the area (Altay-Sayan segment) hosts porphyry Cu and Mo-Cu deposits that generally formed in the Early Paleozoic time, whereas porphyry Cu-Mo deposits in the central part (Northern Mongolia) formed in the Late Paleozoic-Early Mesozoic. The geodynamic setting of the region during these mineralizing events is consistent with Early Paleozoic subduction of Paleo-Asian Ocean plate with the continuous accretion of oceanic components to the Siberian continent and Late Paleozoic-Early Mesozoic subduction of the west gulf of the Mongol-Okhotsk Ocean under the Siberian continent. The eastern part of the study area (Eastern Transbaikalia) hosts molybdenum-dominated Mo and Mo-Cu porphyry deposits that formed in the Jurassic. The regional geodynamic setting during this mineralizing process is related to the collision of the Siberian and North China-Mongolia continents during the closure of the central part of the Mongol-Okhotsk Ocean in the Jurassic. Available isotopic data show that the magmas related to porphyritic Cu-Mo and Mo-Cu mineralization during the Early Paleozoic and Late Paleozoic-Early Mesozoic were mainly derived from mantle materials. The generation of fertile melts, related to porphyritic Mo and Mo-Cu mineralization during the Jurassic involved variable amounts of metasomatized mantle source component, the ancient Precambrian crust, and the juvenile crust, contributed by mantle-derived magmatic underplating.

Trace Element Distribution in Magnetite Separates of Varying Origin: Genetic and Exploration Significance

“…The enrichment in Cr, Co ± Ni is a common feature, recorded in the Skouries, Elatsite, and other porphyry deposits of the Balkan Peninsula, characterized by significant Pd and Pt contents, in contrast to the porphyry-Cu ± Mo deposits of Russia and Mongolia with lower (Pd + Pt) content (less than 25 ppm Cr [49,90]) supports the origin of their parent magma from an enriched mantle source [91,92]. In addition, a salient feature is the evolved geochemical signature of the Skouries and Elatsite porphyry-Cu deposits, as indicated by the negative trend between (Pd + Pt) and Cr contents (Figure 14).…”

Adakites, High-Nb Basalts and Copper–Gold Deposits in Magmatic Arcs and Collisional Orogens: An Overview

“…on our planet, stretching over 4000 km from the Ural Mountains to the Pacific Ocean and separating East European, Siberian, Tarim and Sino-Korean cratonic cores of the Eurasian super-continent [181,182]. The CAOB is richly endowed with Cu-Au-Mo porphyry and epithermal Au deposits of various size and Paleozoic to Mesozoic age [246,247], many of which are associated with adakite magmatism (Figure 18).…”

“…The CAOB includes two principal structural oroclines, the Kazakhstan orocline and the Mongol-Okhotsk belt, both of which are characterized by adakite magmatism [246][247][248][249][250][251][252][253][254][255][256][257][258] (Figure 18). The Kazakhstan orocline is composed of Precambrian crustal fragments, Early (Cambrian to Early Silurian) and Late (Early Devonian to Carboniferous) Paleozoic magmatic arcs and accretionary wedges.…”

“…The granodiorite porphyries hosting Aktogai Cu-Au mineralization display low Y (7.09-13.2 ppm) and Yb (0.71-1.22 ppm) concentrations combined with high Sr (521-923 ppm) contents and Sr/Y ratios over 40 (Figure 19). ; Delmachik [254]; Baley (Taseevsky) [252]; Oui-Tolgoi [256]; Erdenet [246,255]; Shirokinsky [251]; Luginsky [252]; Noion-Tolgoi [252]; Kounrad [249]; Aktogai [246,248]; Duobaoshan [258]; Tuwu-Yandong [246,257]; Bystrinsky [250]; Aksug [247].…”

“…The Kounrad Cu-Au-Mo system displays clear mineral zonation with bornite and chalcopyrite dominating its central part and pyrite-chalcopyrite-galena and sphalerite mineralization occurring within its peripheral parts [249]. Many other Cu-Au-Mo deposits within the Kazakhstan orocline, independently of their size, grade and metal endowment, are associated with felsic magmatic rocks with pronounced adakitic geochemical signature (Figure 19; [246,247,249]).…”