SEDIMENTARY GEOLOGY AND DYNAMIC SEDIMENTOLOGY OF THE DEVONIAN STRATA IN THE WEST QINLING OROGENIC BELT: SEDIMENTARY CHARACTERISTICS AND FRAMEWORK OF THE SMALL-SCALE DEVONIAN CRATONIC BASIN IN THE MIDDLE BELT OF THE WEST QINLING OROGENIC BELT

The Qinling microplate lies between the Shangnan-Danfeng-Wushan and Mianxian-Lueyang-Bashan arc faults.During the Devonian,the bulk of it was in a stable small cra-tonic basin.The present paper focuses on the Devonian sedimentary systems and basin framework viewed from stratigraphy and sedimentology of the Devonian strata in the mid-dle belt of West Qinling orogenic belt.The Xihanhui microprovince in northern cratonic basin is characterized by the terrigenous littoral-shelf depositional systems around palaeo-islands (Eifelian),carbonate platform-organic reef depositional systems (Givetian to Frasian),and deep-water basin and muddy turbidite depositional systems (Famennian), while the Wudu microprovince in southern cratonic basin is dominated by the terrigenous shelf depositional (Eifelian) and ramp-type carbonate platform-shelf depositional systems (Givetian to Famennian).The stable cratonic basin was broken up into two parts by the central Qinling rift trough during the Permian to Triassic.