Continental saline lacustrine dolomite reservoirs remain less understood than their marine analogs. This study investigates the lower Cretaceous Tengger Formation in the western Baiyinchagan Sag, Erlian Basin, using core, thin section, SEM, XRD, isotope and petrophysical analyses. The dark muddy dolomitic rocks are composed mainly of ankerite, albite and natrolite with low clay content, indicating a mixed origin of saline lake evaporation and deep-sourced fluids. Two dolomitization types control reservoir quality: penecontemporaneous dolomitization creates intercrystalline pores, whereas burial dolomitization forms cements that block pores. Dissolution pores and high-angle fractures constitu... More >