The Taos trough (Rowe-Mora basin of earlier workers) of northern New Mexico was one of several tectonically active cratonic basins associated with the late Paleozoic Ancestral Rockies. The basin was an asymmetric, fault-bounded feature flanking the Uncompahgre uplift. The basin fill was controlled primarily by local tectonics. As the basin and adjacent uplift evolved structurally, the depositional systems likewise evolved in conjunction with changing tectonic stability, fluctuating sediment input, evolution and integration of sediment dispersal systems, and varying water depth.

The onset of the first mild structural deformation and encroachment of the sea during Morrowan time was marked by deposition of a complex sequence of fine-grained sandstone, shale, coal, and limestone. These sediments were deposited in a variety of environments including mud flats, marshes, strand plains, and shallow-water carbonate banks. During Atokan time, tectonic activity of the Uncompahgre uplift increased, and subsidence of the basin accelerated. During this time, coarse alluvial-fan, braided-stream, and fan-delta complexes began to fill the basin along its western margin. By middle Desmoinesian time, an extensive coastal plain and a more continuous sediment supply had developed. Meandering rivers with coarse-grained bed-loads fed lobate and wave-dominated deltas. Associated wi h this delta platform were local algal-mound and cross-bedded shelf-edge carbonate accumulations. Basinward, a mixed carbonate and terrigenous slope system developed in conjunction with continued subsidence of the basin.

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