Tectonic Paleogeography Of The Jurassic In The Anqing Area

The research object of this paper is the Jurassic section in Susong and Guache area, Anqing. Through measured section, thin section analysis, draw the columnar section, and geochemical analysis, to analysis provenance, Sedimentary Facies, and the effect of tectonic movement.Jurassic section in Guache is fan delta facies, is a foreland basin, that thin by Dabie mountain orogenic extensional movement in late Indosinian movement to early Yanshan.This Jurassic formation is a set of standards of molasse formation, lithology of gneiss breccia. Provenance from the Dabie mountain area, through the intermountain torrentquick handling, stacking to rift lake lithified into rock.The Jurassic basin to fluvial, swamp-semi deep lake facies, statistics a large number of gravel maximum flat surface analysis of the paleocurrent direction from south to north, gravel were ellipsoidal, high compositional maturity, provenance is the south, not the Dabie mountain nearby. Smooth water flow, stable sedimentary period source structure. Profiles in the upper coal seam and shellfish fossils appear, indicating that the sedimentary environment of stability, water is still water, semi deep lake and swamp facies. Combined with the tectonic evolution of the area, the profile in the early Jurassic sedimentary away from the Dabie mountain, after the early Yanshan stage Ning Zhen movement nearly N-S-trending compressional, collapse area goes to the river.Thistwo Jurassic basin is a large half graben basin, the half graben basin is formed by the Indosinian plate suture zone occurs extension and Dabie mountain postorogenic stage of crustal extension and thinning, Guache area is faulted basin, Heta area is slope.