Potential of Morrow sandstones in southeastern Colorado

Morrow sediments up to 800 ft thick were deposited in Early Pennsylvanian time in the ancestral Denver Basin, an extension of the Anadarko Basin. Two major source areas contributed sediments into the basin. The Cambridge arch-central Kansas uplift on the north and east, which formed the stable flank of the basin, was drained by rather long southward-flowing streams. On the south and west the Sierra Grande-Apishapa and Wet Mt. uplifts contributed a larger volume of coarse terrigeneous sediments. This source area was unstable and continuously growing. Simultaneously, the depositional basin was subsiding rapidly. The conditions under which the basin was filled created a large variety of depositional environments for the sandstone bodies. Among these are deltaic distributary channels, marine sand bars, submarine alluvial fans, and blanket-type transgressive sandstones, all of which form potential reservoirs. Several hydrocarbon accumulations have been found in the Morrow sandstones of SE. Colorado. The stratigraphic component is the primary trapping factor.