page_title: Geography of Qatar
section_title: Geology and mineral deposits
hierarchical_section_title: Geography of Qatar / Geology and mineral deposits
caption_attribution_description: English: Limestone hillock at northern end of Al Khor Island, Qatar.
context_page_description: Qatar is a peninsula in the east of Arabia, bordering the Persian Gulf and Saudi Arabia, in a strategic location near major petroleum deposits. Qatar occupies 11,437 km² on a peninsula that extends approximately to 160 km north into the Persian Gulf from the Arabian Peninsula.
  Varying in width between 55 and 90 km, the land is mainly flat and rocky. Notable features include coastal salt pans, elevated limestone formations along the west coast under which lies the Dukhan oil field, and massive sand dunes surrounding Khawr al Udayd, an inlet of the Persian Gulf in the southeast known to local English speakers as the Inland Sea.
context_section_description: Most  of Qatar's surface lies on Cenozoic strata. These strata have an abundance of mineral resources, most of which have not yet been exploited, such as limestone and clay. The Upper Dammam Formation in the Middle Eocene period is the most predominant surface layer. It is constituted by limestone and Dolomite. The northern zone of Qatar, which comprises the most significant source of fresh groundwater in the peninsula, primarily draws its water from the Umm Err Radhuma Formation and Rus Formation dating to the Paleocene and Lower Eocene periods, respectively. The Mesozoic strata are the most important layers as they contain petroleum. The first substantial deposit of crude oil was discovered in 1940 in the Jurassic period Arab Formation.
caption: Limestone hillock on northern end of Al Khor Island
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