Published online by Cambridge University Press: 13 October 2009
In the Primorye region, various syngenetic and epigenetic minerals are known from Permian and Triassic deposits. The main co-sedimentary mineral deposits are bituminous coals, limestones, glass sandstones, and rocks used for building stones. There has long been interest in the possibility of recovering syngenetic gold from the basal Triassic beds. Permian and Triassic deposits enclosing epigenetic endogenous minerals are known from South Primorye (tungsten, gold, and other polymetallic minerals) and Sikhote-Alin (tungsten, boronsilicate, and other polymetallic mineralizations).
Triassic coal accumulation in South Primorye
In Primorye, alternating Triassic marine and terrestrial freshwater deposits are widely distributed. Coal deposits have been traced for great distances (more than 500 km), as from the coast of Peter the Great Bay in the south to the Bikin River basin in the north. Triassic coal deposits have been found in drill cores from depths of 1,510–2,100 m near the village of Borisovka (to the northwest of the town of Ussuriisk), indicating the possibility of significant deposits at great depths. Throughout the area there are numerous coal dumps alongside old mining sites, the documentation of which has not been preserved.
Coal deposits have been better studied in the Vladivostok coal region, where coals of Triassic, Cretaceous, and Tertiary age have long been known. Triassic coals attracted the attention of many miners at the end of the nineteenth century, when Vladivostok was built as a naval base. Spontaneously, without proper geological study, mining franchises were let, and small mines and adits were worked for coal.