Ore-forming Response to Syndepositional Submarine Volcanism in Langshan-Zhaertai Mesoproterozoic SEDEX Ore Belt, Inner Mongolia, China

摘要

Ore-forming process of the Dongshengmiao, Huogeqi, Tanyaokou and Jiashengpan deposits in Langshan-Zheartai Mesoproterozoic SEDEX metallogenic belt is closely related to the syndeposi- Tional volcanic activities based on the following facts: (1) The Sm-Nd isochron age of the basic vol- Canic rocks varies from 1 491 Ma to 1 842 Ma (more than or close tot he model age of the lead iso- Tope of all sulfide minerals) in these deposits, with ε(Nd, t)=3.48-6.40)±0.80, whose REE Composition is enriched in LREE and depleted in HREE, indicating that these volcanic rocks were Derived from the mantle or lower crust.