Abstract:  Tuolahaihe graphite deposit is the first super-large scale crystalline graphite deposit discovered in Qinghai Province, which is located in the southern margin of Qaidam basin and the middle part of East Kunlun. The ore bodies appear in bedded and near bedded within gneiss, calcareous gneiss, quartz schist and marble of the Lower Proterozoic Jinshuikou Group, which belong to a typical gneiss graphite deposit. In order to discuss ore genesis, detailed petrography, whole-rock geochemistry and isotope geochemistry studies have been carried out on the ore-bearing strata. The results show that ΣREE in graphite gneiss and graphite quartz schist containing graphite is 82.95×10-6-154.86×10-6,enriched in light rare earth elements, with obvious Eu negative anomaly and weak Ce negative anomaly, showing the protoliths formed in anoxic depositional environment of the shallow sea at the continental margin. The protoliths of ore-hosting metamorphic rocks are organic-rich sandy rocks, greywacke and calcium silicate rocks, and the material sources are mainly terrigenous debris and a small amount of them are shallow marine carbonate rocks. The δ13C isotopic composition of graphite gneiss and marble indicating that   the carbon in graphite comes from bioorganic carbon, while and carbon of marble is inorganic carbon. Tuolahaihe graphite deposit is a regional metamorphic graphite deposit that formed in Paleoproterozoic.

Key words: Tuolahaihe graphite deposit, crystalline graphite, geochemical, carbon isotope, ore genesis