Fusulinid paleontology and biostratigraphy of the Middle Permian (Guadalupian) strata of the Glass Mountains and Del Norte Mountains, west Texas.

摘要

Study of new collections of fusulinids from the Guadalupian Series in the Glass Mountains and Del Norte Mountains, west Texas, documents the presence of 44 species (in 10 genera) of fusulinids in the Middle Permian strata. Of these, 14 species are new, the genus Yangchienia Lee, 1933, is reported in North America for the first time, and one species of Rauserella Dunbar, 1944, two species of Lantschichites Toumanskaya, 1953, six species of Reichelina Erk, 1941, one species of Paradoxiella Skinner and Wilde, 1955, and 10 species of Parafusulina Dunbar and Skinner, 1931, are reported from this area for the first time. All species are documented with illustrations. This is the basis for a more detailed fusulinid zonation. The Guadalupian fusulinid-bearing sequence of strata in the Glass and Del Norte mountains area contains abundant fusulinid faunas and is as complete as that of the Guadalupe Mountains area. Diverse fusulinid faunas occur in the Road Canyon Formation and the Altuda Formation. The Mesogondolella serrata (conodont) first appearance datum lies between the Parafusulina boesei first appearance datum and the Parafusulina rothi first appearance datum, within the Road Canyon Formation.; Nine fusulinid zones have been recognized. Of these zones, the Parafusulina durhami Zone is placed in the Leonardian Stage, the Parafusulina boesei Zone spans the boundary of the Leonardian and Guadalupian, and the Parafusulina rothi Zone, Parafusulina trumpyi Zone (Roadian Stage), Parafusulina sellardsi Zone, Parafusulina antimonioensis Zone (Wordian Stage), Polydiexodina shumardi Zone, Reichelina lamarensis Zone and Lantschichites splendens Zone (Capitanian Stage) are placed in the Guadalupian Series.