Laserfiche WebLink
• <br />General Geology <br />The Expansion Areas consists of Quaternary age sand and gravel deposits similar to those <br />being mined in the adjacent Worthing Pit. Deposited by the South Platte River and its <br />tributaries, these aggregates are of the Post-Piney Creek Alluvium and form a surface <br />cover on the Louviers Alluvium. Louviers Alluvium overlies the sandstones and shales of <br />the Cretaceous Denver-Arapahoe Formation, the oldest unit in the Expansion Areas. This <br />is the bedrock formation for the Expansion Areas .and is composed of very thin to thick- <br />bedded clayey, silty sandstone and sandy silt stone with interbedded carbonaceous silty <br />shales and claystone. The carbonaceous shale is light to medium dark grey and locally <br />contains plant fragments with few poorly preserved leaf imprints. The well-graded sand <br />and gravel in this formation consist of approximately 65 percent quartz, 15 percent <br />feldspar, and 20 percent rock fragments made up of granite, argillite, very weathered <br />metamorphics, chert and claystone. <br />excerpt from 2006 report AFS Worthing Pit. <br />• <br />•