It was recognized as a basin in 1926 by Charles N. Gould who gave its present name. Exploration and drilling have been slow and sporadic since that time, the present deep-well saturation being less than one test per 150 square miles. At present, there are one small gas field and one oil field within its limits; around its margins eight other oil pools are producing, of which the Anton-Irish is the largest.

It is bounded on the north by the Amarillo Mountains and their westward continuance, the Bravo dome; on the west by the New Mexico Highlands; and on the south by the Matador line of basement peaks. Having approximately 1,000 feet of general closure along its deepest axis, it opens eastward into the Hollis-Hardeman basin, and southward into the Midland basin.

Structure within its limits is complex with sharp folding accompanied by high-angle faulting trending primarily northwest-southeast. Subordinate to this prominent trend, a low-relief counter-trending system of folding is becoming more apparent with latest control.

The basin probably had its inception near the beginning of Pennsylvanian time when the surrounding regional structural components had their initial movement. Structural movement along these axes has continued through the most recent deposits in the area. Movement along the buried Amarillo Mountains was noted as recently as three years ago when the last tremor emanating from the area was felt.

Historically, the area was an embayment of the major Permian-Pennsylvanian sea on the south and east. Sediments in this interval are closely akin to their counterparts in the surrounding area. Lower Permian and Pennsylvanian shales, carbonates, and sands appear identical with the same

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deposits in the surrounding basins. The great carbonate development of this interval extends into the area from the south and east and is of comparable magnitude. Within the clastic part of the basin the few wells penetrating this section have encountered well developed local sand and arkose deposits. The facies relationships here are the same as those in the Midland basin, with carbonate deposits averaging 800-1,200 feet thick and clastics ranging from 2,000 to 3,000 feet.

Pre-Pennsylvanian stratigraphy for the basinal area is comparatively simple. There is a basal sand of possible Cambrian age locally developed on the pre-Cambrian basement surface. In southeast Swisher County in the heart of the basin it reaches a thickness in excess of 200 feet. Here, it is a fine to coarse, porous sand, glauconitic in part. Above this the Ellenburger dolomite extends into the area from the east and southwest but is missing due to either erosion or non-deposition over the wide central part of the area along the axis of John E. Adam's "Texas Peninsula." From this Ellenburger remnant to Mississippian time there are no deposits present. The Mississippian consists of approximately 600 feet of carbonates near the south limits of the basin, thinning as it approaches an eros onal edge along the south margin of the Amarillo Mountain structure. The relationship of the Osage, Meramec, and Chester shows that these rocks were eroded by early Pennsylvanian orogeny.

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