The Reklaw Formation in Texas marks the beginning of the Claibornian sea during the Eocene period. By studying this formation, researchers focused on marine boundaries and used a sequence stratigraphic approach to map the area in 3D. They found evidence of a marine transgression that included a transgressive systems tract and a shelf margin wedge made up of specific rock layers. This study provides valuable insights into the geological history of the Texas Gulf Coast during the Eocene era.