Polymetallic and Au‐Ag Mineralizations at the Mutnovskoe Deposit in South Kamchatka, Russia

Abstract

. The Mutnovskoe deposit located in the Porozhisto‐Asachinskaya metallogenic province of South Kamchatka, Russia, is a polymetallic vein and Au‐Ag quartz vein associated type of hydrothermal deposit. The Mutnovskoe deposit is located inside a paleo‐caldera structure at the center of the Mutnovsko‐Asachinskaya geothermal field of Pliocene ‐ Quaternary age, where active gold deposition is identified in hot spring precipitate. The Mutnovskoe deposit is subdivided into the north flank, the central flank and the south flank based on the vein distributions and mineral parageneses. The mineralized vein system is oriented N‐S hosted in diorite ‐ gabbroic diorite stock, volcanic rocks and sedimentary rocks of Miocene ‐ Pleistocene age. The mineralization stage I (polymetallic vein) mainly in the central and the south flanks is Zn‐Pb‐Cu‐Au‐Ag contained in sphalerite, galena and tetrahedrite‐tennantite group mineral. The stage II (Au‐Ag quartz vein) occurs in the north and the central flanks. The stage III (Mn‐sulfide and Mn‐Ca‐carbonate vein) occurs in the whole deposit area. Stage II is the typical Au‐Ag quartz‐adularia vein of low‐sulfidation type. Stage III is alabandite‐rhodochrosite‐quartz‐calcite vein. The K‐Ar ages are 1.3±0.1 Ma for stage I sericite in alteration zone, and 0.7±0.1 Ma for the stage II adularia in mineralized vein. Based on the fluid inclusion study, range of ore forming temperature of the Mutnovskoe deposit is 200 to 260d̀C (av. 230d̀C). Salinities of fluid inclusions indicate 2.2 to 5.7 wt% NaCl in sphalerite and 0.8 to 3.3 wt% NaCl in quartz for the stage I. Mineral paragenesis of the polymetallic vein (stage I) is characterized by a district zoning of tennantite and Cd‐rich sphalerite in the south flank and tetrahedrite and Mn‐rich sphalerite in the central flank, which is due to the fractional crystallizations of ore‐forming fluid. Depositional condition of the low sulfidation state is inferred for the Mutnovskoe deposit, where the polymetallic vein of the south flank is in relatively higher sulfidation state than the central flank.

Ore‐forming Ages and Sulfur Isotope Study of Hydrothermal Deposits in Kamchatka, Russia

“…The Nokleberg et al (1997a, b); Ispolatov et al (2004); Kirmasov et al (2004);Solov'ev et al (2006). Ore-forming ages are from Takahashi et al (2002Takahashi et al ( , 2006Takahashi et al ( , 2007; Okrugin et al (2007a, b, c) and this study. CKY: Central Koryak, CK: Central Kamchatka, and EK: East Kamchatka metallogenic belts (Nokleberg et al, 2005).…”

“…Nokleberg et al (2005) summarized the mineralogical description of ore deposits in Kamchatka, and then categorized the Cenozoic hydrothermal deposits into the Central Koryak, Central Kamchatka, and East Kamchatka metallogenic belts. Ore-forming ages and physicochemical conditions for the epithermal ore deposits in East and Central Kamchatka belts have been reported by Takahashi et al (2002Takahashi et al ( , 2004Takahashi et al ( , 2006Takahashi et al ( , 2007 and Okrugin et al (2007a, b, c), respectively. These age data are summarized as Pliocene to Pleistocene in the East Kamchatka belt (Rodnikovoe, Mutnovskoe and Asachinskoe ore deposits), and Miocene (Zolotoe, Ostantsovoe and Aginskoe) and Pliocene to Pleistocene (Baranievskoe) in the Central Kamchatka metallogenic belt.…”

“…Ore forming ages of hydrothermal deposits in Kamchatka had been reported in previous studies; c. 20.4 Ma for the Zolotoe deposits (Okrugin et al ., 2007a), c. 8.9 Ma for the Ostantsovoe prospect (Okrugin et al ., 2007b), and c. 2.9–2.4 Ma for the Baranievskoe deposit (Okrugin et al ., 2007c) in the Central Kamchatka metallogenic belt; and 4.7–3.1 Ma for the Asachinskoe deposit (Takahashi et al ., ), 1.1–0.9 Ma for the Rodnikovoe deposit (Takahashi et al ., ), and 1.3 and 0.7 Ma for the Mutnovskoe deposit (Takahashi et al ., ) in the East Kamchatka metallogenic belt (Figs , ).…”

“…Ore‐forming ages and physicochemical conditions for the epithermal ore deposits in East and Central Kamchatka belts have been reported by Takahashi et al . (, , , ) and Okrugin et al . (2007a, b, c), respectively.…”

Copper-Excess Stannoidite and Tennantite-Tetrahedrite as Proxies for Hydrothermal Fluid Evolution in a Zoned Cordilleran Base Metal District, Morococha, Central Peru

“…In order to understand the role of As and Sb in stannoidite, we compiled a database of 81 published compositions from polymetallic and precious metal ore deposits worldwide and compared them to our 56 data points for the Morococha stannoidite. Published data have been included from the Elshitsa deposit, Bulgaria (Kouzmanov 2001), the Colquijirca deposit, Peru (Springer 1968, Bendezú & Fontboté 2009), polymetallic veins near the Maggie Cu-Mo deposit, Canada (Jambor & Owens 1987), the Shin-Ohtoyo deposit in Japan (Imai et al 1999), and various locations in the Urals, Russia (Kovalenker et al 1986, Takahashi et al 2006, Plotinskaya et al 2009). In addition, we added published data on As-and Sb-free stannoidite from Chelopech, Bulgaria (Petrunov 1994 (Springer 1968), and from various locations in Japan (Kudoh & Takéuchi 1976, Yamanaka & Kato 1976, Shimizu & Shikazono 1987 and the Urals, Russia (Moloshag et al 2005).…”