Editing Ghawar Field (section)

== Geology ==
Ghawar occupies an [[anticline]] above a basement fault block dating to [[Carboniferous]] time, about 320{{nbsp}}million years ago; [[Cretaceous]] tectonic activity, as the northeast margin of Africa began to impinge on southwest Asia, enhanced the structure. Reservoir rocks are [[Jurassic]] Arab-D limestones with exceptional porosity (as much as 35&nbsp;% of the rock in places), which is about {{convert|280|ft|m}} thick and occurs {{convert|6,000|to|7,000|ft|m}} beneath the surface. [[Source rock]] is the Jurassic Hanifa formation, a marine shelf deposit of mud and lime with as much as 5&nbsp;% organic material, it is estimated that 1&nbsp;% to 7&nbsp;% is considered good oil source rock. The [[Petroleum reservoir#Seal / cap rock|seal]] is an [[evaporite|evaporitic]] package of rocks including impermeable [[anhydrite]].<ref>{{cite web |url=https://explorer.aapg.org/story?articleid=2185 |title=Finding Ghawar: Elephant Hid in Desert |author=Rasoul Sorkhab |work=[[American Association of Petroleum Geologists|AAPG]] Explorer |date=June 2011}}</ref>