Devonian sequence stratigraphy of central Longmen Mountains, Sichuan

The Devonian strata are well developed in the Baishi-Goujia region of central Longmen Mountains,Sichuan. Nine sequences which may be assigned to four sequence sets have been distinguished in the light of relative sea-level changes based on lithology, sequence stratigraphy, ecology. The individual systems tracts of each sequence are discussed in detail, and sequence stratigraphic framework of Devonian to Early Carboniferous is constructed for the study area. The Devonian strata in this region generally exhibits a succession of shallowing-upward sedimentary sequence, indicating a deep-water basin environment during the early Emsian(Early Devonian), and still a deep-water sedimentary envi-ronment in the west but a shallower-water sedimentary environment in the east during the early Middle Devonian.