Tectonically induced clastic-carbonate depositional sequences of the Pennsylvanian-Permian transition in the Rowe-Mora Basin, northern New Mexico
— K. Krainer, S. G. Lucas, and B. S. Kues
One of the few places in the late Paleozoic Rowe-Mora basin of northern New Mexico that preserves a section through the traditional Pennsylvanian-Permian boundary is near Canovas Canyon in the Sangre de Cristo Mountains, northwest of Las Vegas. At this section, the Alamitos Formation is ~ 172 m thick and has late Desmoinesian fusulinids in its lower part, and late Virgilian-Wolfcampian fusulinid and invertebrate macrofossils in its upper part. Macrofossil assemblages consist largely of crinoid and bryozoan fragments, and brachiopods (chiefly Composita subtilita and Neosprifer dunbari), indicating shallow, normal marine carbonate shelf depositional environments. The Alamitos Formation at Canovas Canyon was deposited on the northern part of the Pecos shelf and is composed of nonmarine (arkosic sandstone, conglomerate, and reddish-purple shale) and marine (shale and limestone) lithofacies. These lithofacies form six, well-developed asymmetrical transgressiveregressive (T-R) depositional sequences. There is much evidence of synsedimentary tectonics of the ancestral Rocky Mountain deformation in the Rowe-Mora basin during the Late Pennsylvanian, and formation of the Alamitos Formation depositional sequences at Canovas Canyon is interpreted as having largely been induced by tectonic movements. Eustatic sea-level changes caused by the Gondwana glaciation, which are responsible for cyclic sedimentation on tectonically stable shelf areas during the late Paleozoic, are interpreted as being of lesser importance in the Canovas Canyon section.
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- Krainer, K.; Lucas, S. G.; Kues, B. S., 2004, Tectonically induced clastic-carbonate depositional sequences of the Pennsylvanian-Permian transition in the Rowe-Mora Basin, northern New Mexico, in: Geology of the Taos Region, Brister, Brian S.; Bauer, Paul W.; Read, AdamS.; Lueth, Virgil W., New Mexico Geological Society, Guidebook, 55th Field Conference, pp. 314-325.