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i 1 1 1 ~• i <br /> 1 <br />Throughout the area the pierre Shale is easily eroded, <br />forms lo•w'_and5, and generally its vegetation ccver is sp_rse. <br />4t the °ourg (line, the top of the Fierre Shale is a <br />'siltstone, very lioht brownish tray, uesthering alnost white, <br />due apparently to being petroliferous, This siltstone is <br />clean, well sorted, hard and tough, <br />The Fierre Shale, including this siltstone at the top, <br />was decosited in a marina environment, judcing from (1) even <br />bedding, (2) fins grain size, (3) excellent size sorting, <br />and (4) fragments of marine fossils found Haar the nine, <br />especially of the clam Incceramus. <br />~~ Fossils in and recional corr=_laticns of the Fierre Shale <br />date the formation as Late Cretaceous. The contact with the <br />_ overlying Coalmont Formation is an unconfcrmity although <br />~ no angular discordance is evident at the Douro f•'ine. <br />Coalmont Formation <br />Resting unconformably on the Fiarra Sh=_le is a series <br />of littoral and continental elastics and subordinate teal <br />beds which 6eekly (1915) called tha Ccalmont Formation from <br />outcrops near Coalmont, Cole_ade. The bzsal b=_d cf the Coal- <br />mOnt Formatlon In the V1Cln'_ty Of tha cCUrO ail na and In mOSt <br />of flJorth park is the Sudduth coal _=aam. ?t the Eeura fiine <br />the Sudduth Seam averages 25 feet thick. Starting at its <br />base, it consists typically of 2 feet of hard, shiny, black <br />subbituminous coal, ~ feet of alt~rnatine lanticular bads of <br />Dray, hard bone and coal, and 1C feet cf ,.cal as at ti-,e basa. <br />F: <br />C-9 <br />