| Description |
x, 58 leaves : illustrations, maps ; 29 cm |
| Summary |
"Lithologic and thickness data of the Lower Ordovician rocks of the Roubidoux Formation, south central Missouri, were interpreted from sample logs. Maps included are based on structure, thickness and lateral and vertical lithologic variability. Sand distribution in the Roubidoux is represented by a "sand percentage" map, a "sand isolith" map, and a "tripartite sand distribution" map. The Roubidoux Formation consists of a sequence of dolomite, sandy dolomite, sand and chert. It is believed that the Roubidoux was deposited on a stable marine platform receiving a supply of elastics from the north and northeast. The sands were deposited by longshore or coastal currents paralleling the Roubidoux strandline in Kansas. Sand transport was greatly affected by the velocities of surface currents and water depth. Most sand accumulated along low water shoals. The sand probably settled as broad linear ridges that underwent erosion concurrently with the deposition of these ridges, transporting the ridge sands into the lows between ridges, giving the sands a sheet-like character. Most sand is concentrated in the eastern half of the mapped area, where it is distributed throughout the formation, whereas sands in the west are concentrated in the upper third. Detailed correlations are limited by the lack of drillholes in the region. Also, the partial or complete removal of the formation in outcrop, and the partial or complete removal of carbonate as a by-product of dissolution processes falls short providing a satisfactory data base"--Abstract, leaves ii-iii. |
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