Abstract:

Sanjiazi deposit is one of the scheelite deposits in Northeastern China found in recent years. In order to discuss the metallogenesis, their geological and geochemical characteristics of the deposit is studied, including the composition of REE and trace elements in metallogenic granitic rocks, marble wall rock as well as in skarn ores. These granitic rocks containing scheelite mineralization, has similar geochemical features with those of the I-type granites, such as aluminium super-saturation, variable alkaline composition, K₂O>Na₂O and low ratio of Rb/Sr.  Moreover, the facts of low content of REE, negative δEu anomalies, unobvious δCe anomalies and right-declining chondrite-normalized REE patters demonstrate that tungsten-bearing granitic rocks was derived from deep crust or upper mantle. Together with geological features of the deposit, contents of trace elements and sulfur isotope in different rocks and ores, a conclusion can be drawn that the ore-forming materials, including W element, may come from the Mengjialing intrusion. The Sanjiazi scheelite deposit belongs to the skarn deposit and is related to the NW subduction of the Pacific plate underneath Eurasia plate in the Early Yanshanian period.

Key words: scheelite deposit, geochemistry, metallogenesis, skarn deposit, Sanjiazi, Jilin Province