2009-05-29_REVISION - M1977211 (6)

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• Verdos Alluvium (Qv) The Verdos Alluvium is locally a poorly-sorted, stratified gravel containing lenses of sand, silt, and clay. The deposits are typically up to 70 feet thick. Pierre Shale (Kp) Immediately east of the limestone, and essentially underlying the processing plant, shop area, and stockpile areas, is the Pierre Shale. This is a Cretaceous marine formation that is over 5,000 feet thick. In a few places, the shale can be found in direct contact with the Manitou Limestone. This discontinuity is made possible by a fault that may have a displacement best measured in thousands of feet. Where the two formations meet the shale, in particular, is severely twisted, folded and otherwise contorted because of this fault. In some areas north of the current pit, the shale is thrust over the Manitou Limestone. This rock has no value as an aggregate since it is essentially an easily-weathered, high clay content shale. • The measured dips in the vicinity of the pit are highly erratic, and vary from 74 degrees to the east to overturned 40 degrees to the west. Missing Formations Between the Pierre Shale and the Manitou Limestone is supposed to be many thousands of feet of various sedimentary rocks including, to name a few, Niobrara Limestone, Dakota Sandstone, Morrison Formation, Lyons Sandstone, and the very thick Fountain Formation found in the Garden of the Gods. These units have not been exposed at the site because of the fault offset between the Pierre Shale and the Manitou Limestone. The fault offset between these units represents about 440 million years. Manitou Limestone (Om) The Manitou Limestone is an Ordovician aged limestone deposit that • averages about 250 to 350 feet thick. We have mapped all of the locally occurring TRANSIT MIX AGGREGATES 8 PIKEVIEW QUARRY SLOPE CTLIT PROJECT NO. CS17341-125 S:ICS17000-174991CS17341.000112512. ReportsICS17341-125-R1-Final.doc