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The convenient models for orogenic Au deposits suggest they formed within the ocean-facing accretionary wedges, simultaneously with Cu-Au porphyry deposits in the adjacent magmatic arcs. However, some of the world's largest orogenic Au deposits in the Yenisei, Tien Shan, Lena-Bodaibo, and Kolyma subprovinces of northern Eurasia occur in the rear (continent-facing) part of magmatic arcs, always emplaced into sutured backarc basins, coevally with the granitoid intrusions. Despite these general similarities, every subprovince reveals individual signatures.
In the Yenisei Ridge in Siberia, the Neoproterozoic orogenic Au deposits (>30 Moz) are arranged along four belts striking in the NE direction, obliquely to the orientation of the ridge. This suggests a strike-slip control of the metallogenic belts. The position of respective subduction zone is not clear. The age of mineralization, based on old data, is ca 794 and 615 Ma.
In the Tien Shan, the orogenic Au deposits (>300 Moz) were discovered along the 2000 km strike length. The individual deposits again occur in oblique belts relative to the strike of the orogen. Previous models suggested that these orogenic Au deposits were emplaced into accretionary wedge in front of the Beltau-Kurama arc, where superlarge Cu-Au porphyry deposits have been formed. However, recent studies revealed that the porphyry deposits are 305-325 Ma old, whereas the orogenic gold deposits are ca 290 Ma old along the 2000 km strike of the Tien Shan, emplaced into pre-existing terranes irrespective of their type. The oblique pattern suggests strike-slip control during emplacement of deposits synchronously with 290 Ma granitoids. These granitoids occur in the rear part of the Silk Road arc to the south, indicating that the Tien Shan orogenic gold deposits formed in the rear part of the arc.
In the Lena-Bodaibo subprovince, the strike-slip pattern is not recognizable, but the orogenic Au deposits (100 Moz) were again emplaced in the rear part of the late Paleozoic Orkhon-Selenga arc, whose active subduction zone is reconstructed at the Khangai-Khentiy accretionary wedge of Central Mongolia. The deposits were superimposed in late Paleozoic times onto Patom orocline filled with much older Mesoproterozoic rocks on the northern periphery of the Angara-Vitim batholith. Age dating revealed that orogenic Au deposits formed synchronously with emplacement of the batholiths and thrusting of the Patom Highlands onto the Siberian craton..
In the Kolyma subprovince, the orogenic Au deposits (>150 Moz) occur in the rear part of the oroclinally bent Early Yanshanian arc. They are emplaced into strongly deformed formations of Middle Paleozoic to Jurassic passive margin. The rich placer and hardrock deposits occur around the Late Jurassic to Early Cretaceous granitoids. Some of the deposits, especially in the Tenka trend occur along the strike-slip faults. This Au mineralization is synchronous with some epithermal deposits in the magmatic arc.
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