Earth’s Orbital Control on Organic Matter Enrichment in the Black Shales of the Wufeng–Longmaxi Formation in the Upper Yangtze Region, South China

China’s most successful horizon for shale-gas exploration and development is the Upper Ordovician Wufeng Formation through Lower Silurian Longmaxi in its Yangtze Region. In this study, Wufeng–Longmaxi black shales Region are analysed to determine their microstructural characteristics, total organic carbon (TOC) content, well log characteristics identify information on parameters of Earth’s orbit from gamma-ray (GR) data series. Then, paleoenvironmental modes established over a long time scale. On basis, orbital control matter enrichment examined. The lower rich biogenic siliceous fossils framboidal pyrite. Their TOC GR value, uranium (U) content increase gradually bottom Guanyinqiao Member at top, peak Member, then decrease up Formation. Approximately six seven eccentricity cycles can be identified curves Formation, respectively. During minima, corresponding cold period, have relatively high level matter. This study provide an important reference investigating mechanism by which orbits climate sedimentary environment, as enrichment.