Marine Red Beds Research Articles

Cylindrical Structures in Permian(?) Siltstone, Eagle County, Colorado

In the East Brush Creek area a calcareous siltstone bed contains numerous cylindrical structures normal to the bedding. The bed is 35 feet above the conglomerate of other workers in the region. The conglomerate is here considered Permian(?) rather than Triassic, because the Shinarump of Arizona and Utah probably pinches out west of the area. The siltstone bed is in the transition from underlying continental conglomerates and sandstones to overlying marine red beds, and a littoral or estuarian environment is indicated. The cylinders occur throughout the total thickness of the bed but are restricted to the immediate locality. Cylinder contacts are sharp but slightly irregular, and the material they contain is identical to the surrounding sediment. A circular section of uniform diameter is commonly maintained throughout the length. The greatest exposed length is 4 feet. Diameters range from 1/2 to 8 inches. The cylinders are interpreted as fossil diagenetic springs. The bedding in pipe channels w...