The study aims to discover new prospective areas for deep oil and gas exploration based on the understanding of tectonic and sedimentary response characteristics and evolution patterns of the Xiaoerbulake Formationin

Tarim Basin.Under the guidance of marine carbonate rock sequence stratigraphy and reservoir sedimentology

it's made certain that the Lower Cambrian Xiaoerbulake Formation mainly develops restricted-semi-evaporitic platform

open platform

platform margin

slope-basin facies according to core

logging and seismic data and thin section observation

combined with the features of tectonic paleo-geomorphology.These sedimentary facies can in turn be subdivided into multiple subfacies and microfacies

and their distribution is characteristic of zonation and inheritance.The fine interpretation of the two-dimensional seismic lines across the basin helps to identify the features of seismic responses of the main Cambrian sedimentary facies in Tarim Basin

and recognize six types of seismic facies

namely the intra-platform microbial mound/shoal(SF1)

intra-platform low(SF2)

inter-mound/bank sea(SF3)

gypsum-salt lake(SF4)

platform margin(SF5)and slope-basin(SF6).Then the boundary of sedimentary facies for each facies zone was delineated and the relation of facies zones distribution with paleostructure and paleogeomorphology was revealed.According to the isopach map of the Xiaoerbulake Formation

it's made clear that there is an EW-trending paleo-uplift in the southern basin

and two depressions in the eastern and central basin.The First Terrace lies in the southwestern basin

which transits from the wide and gentle Level 1 slope-break towards the central depression

while the narrow and steep Level 2 slope-break in the central basin rapidly transfers to a deep depression towards the east.In addition

the seismic interpretation results

analysis of outcrop

observation of cores as well as microscopic observation of thin sections were used to generate the lithofacies paleogeographic map of the Lower Cambrian Xiaoerbulake Formation

providing favorable evidences for the exploration of deep carbonate oil and gas in the Lower Cambrian Xiaoerbulake Formation of Tarim Basin.