A dataset of microscope images of Middle Devonian rock thin sections from the Guanwushan Formation in the Northwestern Sichuan Basin

Following the significant progress in oil and gas exploration within the Middle Devonian Guanwushan Formation of the northwestern Sichuan Basin (Northwestern Sichuan), research on its sedimentary reservoirs has gained considerable attention. However, due to the relatively limited depth of fundamental geological investigations, the current understanding of the sedimentary framework of the Middle Devonian Guanwushan Formation in northwestern Sichuan remains unclear, hindering the process of hydrocarbon exploration. To enrich the fundamental geological data of this region, this study selected seven field sections of the Middle Devonian Guanwushan Formation field profiles in northwestern Sichuan, systematically collected and prepared 153 rock samples, with thin-section thickness conforming to both national and international standards. On this basis, rock types, mineral compositions and abundances, textures and structures, fossil assemblages, and diagenetic features across different sections were comprehensively documented. 550 polarized-light photomicrographs were provided, all of which were acquired using automatic exposure and white balance, ensuring high image clarity and the absence of color distortion. The identification results of this dataset strictly follow established specifications and standards and have been repeatedly verified. The dataset provides essential foundational geological data to support sedimentary reservoir studies and oil and gas exploration of the Middle Devonian Guansushan Formation in the Northwestern Sichuan Basin.