|
Shakhtama |
|
|
Russia |
| Main commodities:
Mo Cu
|
|
 |
|
|
 |
Super Porphyry Cu and Au
|
IOCG Deposits - 70 papers
|
All papers now Open Access.
Available as Full Text for direct download or on request. |
|
|
The Shakhtama porphyry Mo deposit is located in Eastern Transbaikalia, Russia, ~700 km east of Lake Baikal, within 50 km to the west of the Russia-China border, and ~150 km SE of the Zhireken porphyry Mo-Cu deposit (#Location: 51° 16' 58"N, 117° 52' 58"E).
It is hosted within the 135 km2 multiphase Shakhtama granitic pluton which is on the southern margin of the Mongol-Okhotsk orogenic belt. This multiphase pluton, which intrudes the Permian Unda granitoid complex and a sequence of sedimentary rocks, is composed of rocks ranging from monzodiorite to granite in composition. Porphyritic rocks associated with mineralisation are dominated by quartz monzonite and granite porphyries that intruded into the Shakhtama pluton. These porphyries belong to the high-K calc-alkaline and shoshonitic series (Berzina et al., 2016).
The age of the ore-bearing porphyry complex is contemporaneous with the Late Jurassic transition from a collisional to an extensional regime, when a number of rift basins filled with thick volcanic and terrigenous sediments began form in the region. Voluminous Mesozoic granitoid batholiths, including the Shakhtama pluton, occur within a NE-trending zone, while the late Mo associated porphyry dykes are distributed along NW-trending extensional structures stretching over tens of kilometres.
In the immediate deposit area, the Shakhtama pluton rocks are intruded by NW-SE striking dykes and stocks of the porphyry complex, some of which have associated explosive breccias on their margins. The bulk of the Mo mineralisation occurs as a series of east-west striking quartz veins and as stockwork veinlet zones, as well as molybdenite disseminations in pegmatoids, but is predominantly hosted within the enclosing plutonic rocks. The molybdenum mineralisation is represented by quartz-molybdenite veins containing pyrite and rare chalcopyrite, genetically related to the emplacement of the shallow level porphyritic intrusions (Berzina et al., 2016).
The Shakhtama pluton has been dated at 169 to165 Ma and the porphyry complex at 161 to 156 Ma (40Ar/39Ar dating of amphibole; Sotnikov et al., 1998). Recent SHRIMP U-Pb zircon dating yielded ages of 163 to 159 Ma for the plutonic complex, while the porphyry complex gave ages of 160 to 153 Ma. The Re-Os age for two molybdenite samples are in the range of 160 to 157 Ma (Berzina et al., 2003).
The deposit has a resource of ~50 Kt Mo at a grade of 0.1% Mo and ~50 Kt Cu at a grade of 0.1% Cu (Berzina et al., 2016), which equates to a tonnage of ~50 Mt of ore (Berzina et al., 2016).
The most recent source geological information used to prepare this decription was dated: 2016.
This description is a summary from published sources, the chief of which are listed below.
© Copyright Porter GeoConsultancy Pty Ltd. Unauthorised copying, reproduction, storage or dissemination prohibited.
Shakhtama
|
|
|
|
|
Berzina, A.N., Berzina, A.P. and Gimon, V.O., 2016 - Paleozoic-Mesozoic Porphyry Cu(Mo) and Mo(Cu) Deposits within the Southern Margin of the Siberian Craton: Geochemistry, Geochronology, and Petrogenesis (a Review): in Minerals v.6, doi:10.3390/min6040125
|
Berzina, A.P., Berzina, A.N., Gimon, V.O., Krymskii, R.Sh., Larionov, A.N., Nikolaeva, I.V. and Serov, P.A., 2013 - The Shakhtama porphyry Mo ore-magmatic system (eastern Transbaikalia): age, sources, and genetic features: in Russian Geology and Geophysics v.54, pp. 589-607.
|
|
Porter GeoConsultancy Pty Ltd (PorterGeo) provides access to this database at no charge. It is largely based on scientific papers and reports in the public domain, and was current when the sources consulted were published. While PorterGeo endeavour to ensure the information was accurate at the time of compilation and subsequent updating, PorterGeo, its employees and servants: i). do not warrant, or make any representation regarding the use, or results of the use of the information contained herein as to its correctness, accuracy, currency, or otherwise; and ii). expressly disclaim all liability or responsibility to any person using the information or conclusions contained herein.
|
Top | Search Again | PGC Home | Terms & Conditions
|
|
