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• Discussion of the Nature and Extent of Unconsolidated Deposits <br />Field examination of the study area confirmed the presence <br />of unconsolidated deposits in the configuration previously mapped <br />by Douglas M. Kinney (Preliminary Geologic Map of the Gould Quad- <br />rangle, North Park, Jackson County, Colorado U.S.G.S. Open File <br />Report 70-182). These deposits consist of two levels of stream <br />laid terrace gravels indicative of episodic uplift and subsequent <br />renued downcutting of the active stream channels through time. <br />Remnant terrace gravel deposits are left at higher elevations than <br />the new stream level thus marking the relative position of the <br />stream in the geologic record. Active flood plain deposits within <br />the Bolton Draw watershed and the two mile radius of the mine were <br />noted only along Bolton Draw. Other active flood plain deposits <br />noted in the vicinity lie outside of the study area within the <br />Michigan River flood plain to the southwest and the Canadian River <br />flood plain to the northeast. These two river systems and their <br />associated stream laid unconsolidated deposits can be very typically <br />• categorized as potential alluvial valley floors based on their <br />geomorphic characteristics. Both of these rivers exhibit all the <br />necessary criteria such as definite stream channels, active flood <br />plains and terraces which are capable of being flood irrigated. <br />The map of the study area (see Supporting Material at the end <br />of this report) illustrates the configuration of the two unconsoli- <br />dated terrace deposits mapped by Kinney as Qt3 and Qot2. According <br />to Kinney, the upper older terrace (Qot2) lies approximately 120 <br />feet above the present stream channel of the Michigan and Canadian <br />Rivers. Field examination of these terrace deposits show them to <br />be major upland drainage divides and are, therefore, to be excluded <br />from further consideration as potential alluvial valley floors <br />based on geomorphic criteria. Furthermore, these terrace deposits <br />have no history of agricultural activity as they are not capable <br />of being flood irrigated. <br />LJ <br />-107- <br />