Lithofacies of the Pennsylvanian Osha Canyon Formation at the type section, Jemez Mountains, New Mexico

A BSTRACT .— The Pennsylvanian Osha Canyon Formation at the type section in the Jemez Mountains (northern New Mexico) is a 27.3-m thick succession composed of fossiliferous marly shale with intercalated limestone beds and a mixed siliciclastic-carbonate sandstone bed on top. Limestone is represented by bioclastic grainstone, locally grading into packstone. The mixed siliciclastic-carbonate sandstone forming the uppermost part of the section contains up to 20% skeletal grains. Sediments of the Osha Canyon Formation were deposited in a shallow-marine shelf environment with