Abstract
The Upper Cretaceous Cliff House Sandstone in the San Juan Basin, New Mexico is characterized by en-echelon, NW-SE elongated linear sandstone complexes representing successive phases of coastal sedimentation along the western margin of the Cretaceous Seaway. Detailed analysis of the lithofacies, spatial facies relations, and geometry of the stratigraphically highest Cliff House Sandstone complex in the southern part of the basin indicates a storm-dominated, tidal linear barrier island coast as the depositional environment. The complex consists of four stacked sandstone bodies; each body is bounded above and below by a sharp erosion surface. Offsets of the stacked sandstone bodies along the erosion surfaces mark minor transgressive and regressive shifts of the Cliff House coast. The Cliff House Sandstone is generally known as a transgressive sequence; accumulation of barrier sands, however, took place during the regressive intervals. In subsequent transgressive intervals, part of the accumulated sediment was eroded, and only topographically low-lying parts of the barrier, e.g., shoreface, tidal-inlets, and lagoonal sediment were preserved.
