LATE WORDIAN AND CAPITANIAN (GUADALUPIAN, MIDDLE PERMIAN) RADIOLARIA FROM THE APACHE MOUNTAINS, WEST TEXAS

The Delaware basin has an ancient Middle Permian Reef Complex with deposits ranging from back reef to basinal with biostratigraphically useful fossils such as ammonoids, conodonts, foraminifers, and radiolarians. Radiolarians are found only in the basinal deposits of the Guadalupe and Apache mountains. In the Apache Mountains radiolarians occur in strata of similar ages to the Hegler, Pinery (late Wordian), Rader, Lamar and Reef Trails Members (Capitanian) of the Bell Canyon Formation in the nearby Guadalupe Mountains. A “Hegler” assemblage occurs in the BWK section and contains Pseudoalbaillella yanahanensis, Ps. scalprata, Follicucullus japonicus, Hegleria mammifera, Latentifistula texana, Tormentum sertulum. A “Pinery” assemblage occurs in the lower part of the B section and contains F. japonicus, and species from underlying strata. The lower boundary of the Capitanian is marked by the first appearance of the conodont Jinogondolella postserrata found in the upper part of the B section. The upper part of the B section, the A and G sections and lower part of the K section are assigned to the lower part of the “Rader Member” equivalent of the Guadalupe Mountains. The assemblage of this part contains species of radiolarians known from underlying deposits and includes Ps. scalprata, F. japonicus, and a new genus and several new species. The upper part of the K section is assigned to the upper part of the “Rader Member” and possibly to the “McCombs Member” equivalents and is characterized by the first appearance of the species Follicucullus dilatatus together with F. japonicus and species known from underlying deposits. The “Lamar Limestone” and “Reef Trail” assemblages are found in the Z, M, QEF, VEF and EF sections and contain a very diverse radiolarian fauna including Follicucullus scholasticus, F. orthogonus, F. sphaericus, Albailella yamakitai, Copicyntroides asteriformis, Ishigaum trifustis, Grandetortura nipponica, and Quadrilobata? blomei. Strata of Bell Canyon equivalent age have a continuous record of radiolarian species whose ranges are important for intercontinental correlation and that can be documented by diagnostic conodont species. Ongoing recent studies have demonstrated that sections of slightly older (Cherry Canyon) radiolarian bearing strata are also present.