Significant amounts of unconventional oil and gas resources have been discovered in the Yanchang Formation of Ordos Basin. Shale layers deposited in Chang 7 member (divided into Chang 7-2 submember (C7-2SM) and Chang 7-3 submember (C7-3SM) and Chang 9 member (C9M)) are the main source rocks. Based on the comparison of mineralogical and geochemical characteristics. it is concluded that... https://yeswellneses.shop/product-category/puzzles/