Study on the Provenance and Tectonic Setting of Mudstone in the Lower Silurian Longmaxi Formation of the Yanyuan Basin on the Western Margin of the Yangtze Platform

This study investigates the provenance and tectonic background of lower Silurian Longmaxi Formation black shale Yanyuan Basin in western Kangdian ancient land provides guidance for gas exploration development area. The mineral petrological geochemical characteristics this area have been studied detail. is mainly a passive continental margin environment, but also has attributes an active island arc environment due to collision between oceanic crust Yangtze crust. source rocks are felsic igneous rocks, with small contribution intermediate–basic rocks. It inferred that eastern part could be main area, sediments derived from located west. During whole period, movement was intense, climate cold, degree chemical weathering low, it highly volatile geological sedimentary basin. Therefore, siliceous organic-rich mudstone, which different Sichuan Basin, deposited.