The Pennsylvanian section at Priest Canyon, southern Manzano Mountains, New Mexico
Spencer G. Lucas, Karl Krainer, and Daniel Vachard
The Pennsylvanian section at Priest Canyon in the southern Manzano Mountains includes the type sections of units named by Myers and long applied to Pennsylvanian strata throughout the Manzano and Manzanita mountains. Detailed restudy indicates it is very similar to the Pennsylvanian section in the Cerros de Amado, ~60 km to the SW, so, the stratigraphic nomenclature introduced by Thompson in 1942 and elaborated by Rejas in 1965 and Lucas, Krainer and Barrick in 2009, can be applied at Priest Canyon. The base of this section is the ~70 m thick Sandia Formation, mostly covered slopes and beds of sandstone, limestone and conglomerate that are in fault contact with the Proterozoic basement. The overlying Gray Mesa Formation (= Los Moyos Limestone) is ~192 m thick and mostly cherty limestone, divided into three members (ascending): (1) Elephant Butte Member, ~24 m of limestone and shale; (2) Whiskey Canyon Member, ~84 m of cherty limestone; and (3) Garcia Member, ~84 m of non-cherty limestone and shale with lesser amounts of cherty limestone, sandstone and conglomerate. The overlying Atrasado Formation (= Wild Cow Formation) is ~272 m thick and divided into eight members (ascending): (1) Bartolo Member, ~66 m of slope-forming shale with thin beds of sandstone, limestone and conglomerate; (2) Amado Member, ~9 m of bedded, cherty, brachiopod-rich limestone; (3) Tinajas Member, ~115 m of shale with interbedded limestone and sandstone; (4) Council Spring Member, ~23 m of mostly algal limestone without chert; (5) Burrego Member, ~26 m of arkosic red beds and limestone; (6) Story Member, ~6 m of limestone; (7) Del Cuerto Member, ~16 m of arkosic red beds and limestone; and (8) Moya Member, ~11 m of bedded limestone and shale. The Pennsylvanian section is overlain by the Lower Permian Bursum Formation, which is at least 30 m of interbedded red-bed mudstone, sandstone, conglomerate and limestone. Deposition of the Sandia, Gray Mesa, Atrasado and Bursum formations took place mostly in normal, shallow-marine platform settings and in coastal, nonmarine fluvial paleoenvironments. At their type sections, Myers’ members of the “Wild Cow Formation” clearly are fusulinid-based, biostratigraphic units, not lithostratigraphic units, as their contacts are not drawn at laterally traceable lithologic changes. Thus, Sol se Mete Member = Missourian fusulinids, Pine Shadow Member = early Virgilian fusulinids, and La Casa Member = middle-late Virgilian fusulinids. We thus recommend abandonment of all of Myers’ Pennsylvanian lithostratigraphic terms because they are either synonyms of earlier named units or do not identify useful lithostratigraphic units. Available biostratigraphic data and regional correlations indicate that at Priest Canyon, the Sandia Formation is late Atokan-Desmoinesian, the Gray Mesa Formation and lower Atrasado Formation are Desmoinesian, and the rest of the Atrasado Formation is Missourian-Virgilian, with its uppermost strata Wolfcampian.
- Lucas, Spencer G.; Krainer, Karl; Vachard, Daniel, 2016, The Pennsylvanian section at Priest Canyon, southern Manzano Mountains, New Mexico, in: The Geology of the Belen Area, Frey, Bonnie A.; Karlstrom, Karl E.; Lucas, Spencer G.; Williams, Shannon; Zeigler, Kate; McLemore, Virginia; Ulmer-Scholle, Dana S., New Mexico Geological Society, Guidebook, 67th Field Conference, pp. 275-301.