transport directions. The Yeso Formation is divided into two members: The Meseta Blanca Sandstone Member contains classic eolian deposits of cross-bedded, well-sorted sandstones. This formation may be equivalent to the De Chelly Sandstone. The San Ysidro Member contains gypsiferous sandstones interbedded with limestones and reflects complex, cyclic facies changes (i.e. eolian, coastal, shallow shelf). The Glorieta Sandstone contains buff to white, silicious sandstones indicative of eolian deposits. The San Andres Limestone (aka, Bernal Formation) contains thick limestone and dolomite beds interbedded with sandstone or shale. Mesozoic Triassic The Moenkopi Formation and the upper Chinle Formation unconformably overlie Permian rocks and consist of continental sandstone, siltstone, and mudstone. Jurassic Rocks of this time period, e.g. the Morrison Formation, contain continental sandstone and siltstone, and marine limestone and anhydrite deposits. Cretaceous The Cretaceous-aged units are the most well-understood and the most productive units in the San Juan Basin. The Inner Cretaceous Seaway's western extent was along the San Juan Basin, and the three major transgressive-regressive episodes that occurred during this time are recorded in the mid- to upper-Cretaceous stratigraphy. The Dakota Sandstone Formation is an early Cretaceous unit consists of fluvial sandstones deposited unconformably over older units. These units grade into the overlying Mancos Shale (see next line). The Mancos Shale represents deeper marine deposits as the Inner Cretaceous Seaway made its first major transgression. This formation is divided into three main members: The Graneros Shale contains sandstone, bentonite, and limestone beds. Then Greenhorn Limestone contains alternating beds of limestone and calcareous shale deposited during a time of maximum transgression. The Juana Lopez Member contains fossil-rich calcareous shale beds. The Mesaverde Group was deposited as the Inner Cretaceous Seaway regressed to the northeast, depositing the Point Lookout Sandstone, and then transgressed to the southwest again, depositing the Cliff House Sandstone. The Lewis Shale contains grey shales interbedded with sandstone and limestone. These are deeper marine deposits as the seaway continued to regress to the southwest. This unit represents the westernmost extent of the Inner Cretaceous Seaway. The Pictured Cliffs Sandstone is divided into two layers: the lower unit contains interbedded Lewis-like shales and sandstones as the seaway began to regress, and the upper unit contains massive sandstone beds as the seaway made its final regression. The Fruitland Formation consists of shale, siltstone, and (most importantly) coal deposited from swamps, rivers, lakes, and flood plains. The Kirtland Formation is divided into two layers: