1. Reconnaissance geologic map of the Harrat Tuffil quadrangle, sheet 20/39 B, Kingdom of Saudi Arabia [cartographic material] Yale Public content 1983. 2023-07-07T19:25:40Z. 2023-07-11T21:35:42Z. Pallister, John S. U.S. Geological Survey. English. cartographic image. Public. Saudi Arabia and Saudi Arabia.