STRATIGRAPHIC FRAMEWORK OF THE MESOPROTEROZOIC TIELING FORMATION IN NORTHWESTERN HEBEI

The Mesoproterozoic Tieling Formation in Huailai, Hebei province, consists principally of an association of littoral neritic carbonate rocks. On the basis of order by order analysis of microfacies assemblages or essential sequences, depositional systems and depositional systems tracts, 61 essential sequences and three depositional systems （i.e. tidal flat, shallow shelf and open shelf） may be recognized. The periodic overlapping of the three depositional systems gives rise to a complete transgressive regressive carbonate depositional sequence, with prominent parallel unconformities at the top and bottom. Through tracing the sequence boundary and maximum transgressive surface of this depositional sequence, the authors establish the stratigraphic framework in the Huailai area, thus revealing the features of the evolution of the sedimentary basin of the Mesoproterozoic Tieling Formation.