from the surface. It was discovered only in 1991. Prior to its discovery, many geologists believed that impact craters were unlikely to contain petroleum. Wells had been drilled near the crater site since the 1960s, but none had been drilled within the crater. However, Continental Resources drilled deep into the crater. The well struck oil at a depth that initially produced about . The crater penetrated the Arbuckle Dolomite which resulted in vast amounts of oil and gas becoming accessible in the fractured rock. There were even rumors that the impact might have created diamonds. But no evidence of that was found. Iridium was also not found although it is used to identify astroblemes elsewhere. At least 60 wells have been drilled in Ames Crater since 1991. About 30 of the original wells were still producing in 2007. According to an article published by the American Oil & Gas Historical Society (AOGHS), Ames had produced over of oil and of natural gas, making it the largest of the six producing astroblemes in the United States. Notes References External links Judson L. Ahern, Univ. of Okla.: Imaging the Ames Impact Structure - good general interest article Ahern, Judson L. "The Potential of Potential Fields for Detecting Buried Impact Structures: Earth and Mars." Denofrio, Richard R. "North American impact structures hold giant field potential." Oil & Gas Journal. May 11, 1998. Retrieved May 17, 2014. Good discussion of why hydrocarbons are found in some meteoric impact structures and not in others. Aerial Exploration of the Slate Islands Structure Osinski, Gordon R. "Meteorite impact structures: the good and the bad." Geology Today. Vol 24, No. 1. January–February 2008. Retrieved May 26, 2014. Impact craters of the United States Ordovician impact craters Landforms of Oklahoma Landforms of Major County, Oklahoma