From the site: "The AAPG, under the direction...

From the site: "The AAPG, under the direction and guidance of the GIS Publications Committee and AAPG Datapages, is building a GIS / spatial library comprised of peer-reviewed Global Framework, Geothematic and Geographic themed projects. The project files are free to the public and can be downloaded from this GIS Open Files page. Other project files are available through the subscription-based GIS-UDRIL program within AAPG Datapages."

Downloads include maps of Sedimentary Basins of the World, Giant Oil and Gas Fields of the World, and Source Rocks of the World.