Devonian sequence stratigraphic classification and establishment of the sequence stratigraphic framework in southern Guizhou,China

The Devonian in southern Guizhou occurs as a large sedimentary wedge. From the deep-water of the Luofu section of Nandan, Guangxi, to the neritic of the Wudang section of Guiyang, the Devonian sequences change from 13 to 5 in number, which resulted from the earlier transgressive pinch-out event and later regressive pinch-out event during the Devonian. The Devonian displays a succession consisting of transgressive clastic sedimentary rocks in the lower part, mixture of clastic sedimentary rocks and carbonate rocks in the middle part and carbonate rocks in the upper part and may be divided into 2 second-order sequences and 13 third-order sequences. The second-order and third-order sequences are both composed of special sedimentary successions. The sequence stratigraphic division of the Devonian and establishment of the Devonian sequence stratigraphic framework provide a good example for the study of the facies shift in the chronostratigraphic and sea-level change framework.