Cyclostratigraphy and astronomical tuning during the Oligocene in the Jizhong Depression, Bohai Bay Basin, northeastern China

The Dongying Formation (Ed) and the first member of the Shahejie Formation (Es1) in the central Raoyang Sag cover about 1705 m-long sedimentary series of terrestrial lacustrine infill. We employed the gamma-ray (GR) log data as a paleoclimatic and paleoenvironmental proxy to conduct the high-resolution cyclostratigraphy research in well W33 and W62. Prominent sedimentary cycles in decameters and meters were revealed by multi-taper (MTM) power...