Distribution and Correlation of Pennsylvanian Rocks in Late Paleozoic Sedimentary Basins of Northern New Mexico

Abstract

The most useful classification of the Pennsylvania series in northern New Mexico is by the lithologic character of the rocks, supplemented by paleontologic data where available. Few of the boundaries are sharp. The strata represent a single major sedimentary cycle, comprising, in ascending order, a suite of transgressive sediments, a widely distributed marine phase, and an unevenly distributed regressive phase, followed by continental sediments. For the marine part of the sequence the term "Magdalena group" is used, including the Sandia formation and the Madera limestone, the latter containing several named members. The positions of major positive areas and of depositional basins, total thicknesses, and general character of the sediments are indicated on a map of northern New Mexico, and detailed local sections are shown graphically in several charts.