The researchers studied sedimentary patterns in a region in China during the Late Cretaceous period. They found that sediment deposition in a shallow lake delta environment created the first member of the Yaojia Formation. The formation consists of delta plain, delta front, and prodelta sub-facies, with distributary channels forming important reservoirs. The study helps understand the geological history of the region and is important for predicting oil exploration targets in the Songliao Basin.