The study examined the rocks in the G-field of the Niger Delta in Nigeria to understand how they were formed. By looking at well logs and core samples, the researchers identified different types of rock layers, like sandstone and mudstone. They grouped these rocks into two main types based on their characteristics. The study found that the rocks were formed in environments like open sea, brackish water, and tidal flats. The data also showed that the rocks were deposited in a way that built up over time.