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Stratigraphic Units and Type Logs
Midland Basin Stratigraphy


(Salt-bearing formation names link to detailed lithologic descriptions.)

Stratigraphic units selected for mapping in the Midland Basin were adapted from cross sections and stratigraphic studies (Adams, 1944; 1968; Herald, 1957; Humble Oil and Refining, 1960; 1964a; 1964b; Tait and others; 1962; Feldman, 1962; Vertrees, 1962; 1963; Snider, 1966; McKee and others, 1967; Mear, 1968; Johnson, 1978; Presley, 1981; Matchus and Jones, 1984; Borns and Shaffer, 1985; McGookey and others, 1988; Hovorka, 1990). The Ochoan Dewey Lake, Alibates, and Salado Formations; and Guadalupian Tansill, Yates, and Seven Rivers Formations are readily identified in the Midland Basin and across the Central Basin Platform. Complex changes in the character and thickness of stratigraphic units reflecting the results of both facies changes and salt dissolution are noted near and across the west margin of the Central Basin Platform/east margin of the Delaware Basin. The Seven Rivers, Yates, and Tansill Formations are laterally equivalent to the Capitan Limestone Reef facies that forms the aggradational and progradational shelf margin of the Delaware Basin. Within the Delaware Basin, stratigraphic units are the Ochoan Rustler, Salado, and Castile Formations and the Guadalupian Bell Canyon Formations. Log analysis and preparation of cross sections, supplemented by core and outcrop descriptions, show the lithologies and facies relationships in each of these units.

Seven Rivers and Yates Formations
Salado and Tansill Formations
Salado Insoluble Residue, Alibates and Dewey Lake Formations
Delaware Basin Stratigraphy
Relationship between the Midland and Delaware Basin Units