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<br />Rinderle Construction
<br />Surficial Geology Investigation, High Desert AFT Subdivision
<br />D & 35 Roads, East Orchard Mesa, Palisade, CO
<br />May 4, 2001 Page 2
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<br />Vegetation on the site includes common desert species of plants, which are native to this area of Colorado. Various
<br />cacti succulents, sage, minor grasses and some remnants of woody plants. Other species include certain types of aquatic
<br />and emergent species along Sink Creek.
<br />The topography of the general area is quite variable, ranging from relatively Flat `uplands in the south and east, to
<br />moderate to steep slopes along the Sink Creek Gully and associated tributary gullies, to gently rolling slopes in the North.
<br />Just north of the tract, the gently rolling land slopes toward the north and is irrigated crop land and orchards. The tract
<br />is at the junction of the ancient Colorado River and the lower pediment at the base of Grand Mesa. The tract is in an arid
<br />to semi-arid environment and erosion is sporadic, oftentimes localized. The tract has an elevation ofapproximately 4710
<br />to 4920 feet above sea level, using the U.S.G.S. 7-1/2 minute mapping of the Clifton quadrangle.
<br />A small earthen dam has been constructed across a tributary of Sink Creek and currently impounds water. It is not
<br />known if the spillway construction is properly sized for potential flood flows. The dam crest is utilized as a road to
<br />access private land to the South and Southeast.
<br />GENERAL GEOLOGY
<br />The general geology of this area consists of a thick series of very gently, east northeastwardly dipping sedimentary beds,
<br />covered with moderately thick (up to 40 feet) deposits of~unconsolidated alluvial coarse grained and fine grained soils.
<br />This particular area has fairly uncomplicated structural geologic features. The site is located on the northeast margin
<br />of the Uncompahgre Uplift and on the southwest margin of the Piceance Basin. The main axis of [lie Uncompahgre
<br />Uplift is approximately 37 miles west, southwest of this site. The axis of the Montrose Syncline is approximately 15
<br />miles east ofthis site. The Ladder Park Monocline and Fault Complex, along [he northeast margin of the Uncompahgre
<br />Uplift is approximately 1 ]miles west, southwest of this site.
<br />Approximately 18 miles north of this site, the East-West trending Debeque Anticline is the largest structural feature on
<br />the southern portion of the Piceance Basin. Several small anticlines, synclines and monoclines have been identified in
<br />the Bookcliffs, immediately North of the Town of Palisade.
<br />This general area is underlain by the middle units ofthe Mancos Shale Formation, which outcrops along the lower edges
<br />ofthe Sink Creek Gully and smaller tributary gullies. Based upon information availableto Lincoln DeVore, it is believed
<br />the dip of the sedimentary beds beneath this sRe would be between 2 to 5 degrees, into the Piceance Basin, with a strike
<br />of approximately 30 degrces to 45 degrees West of North.
<br />General and Specific information concerning the area geology is contained in:
<br />1. CASHION,W.B.,1973, Geologic andS~ruclureMupojtheCrandJunclionQuadrungle.ColoradoandUlah.US.G.S.
<br />Misc. Geol. Jnvesl, Map /-736.
<br />2. WILLIAMS, P.L., 1964, Geology, Structure and Uranium Deposits ojlhe Moab Quadrangle, Colorado and Utah.
<br />US.G.S. Mis. Geol. lrrvesl, Map /-360, 2 p.
<br />3. WHlTNEY,J.W.,1981,Su~cialGealogicMapojtheGrandJunctionQuadrangle,ColoradoandUtah,USG.S.Misc.
<br />Geol. lrrvest., Map 1-/289.
<br />4. LOHMAN, SW., 1963, GeologicMupoJ'lheGrandJunclionArea, Colorado, U.S.G.S. Misc. Geol, /Hues[., Mup 1-40d
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