Laserfiche WebLink
GRAND JUNCTION PIPE <br />Surficial Geology Investigation, <br />September 13, 2000 <br />Bradbury Pit II, Southeast of Whitewater, Colorado <br />Page 4 <br />The tract is approximately 7 miles west of the margins of a natural gas production field on the lower slopes of Grand Mesa. <br />The natural gas production is generally within the Mesa Verde Formation and Dakota, Burro Canyon/Cedar Mountain <br />Formation. The Dakota, Burro Canyon/Cedar Mountain Formations are exposed west of this tract but natural gas <br />production is not anticipated. It is possible that some natural gas may be encountered in deeper beds but, no information <br />regarding deeper petroleum development has been found during our literature search in the Grand Junction area. <br />The tract is about S miles south of the Gunnison River Coal/Lignite District. These coals and lignites are generally quite <br />thin and of limited arcs. Carbonaceous materials have bcc a observed in the banks of tho Gunnison Rivcr, north of this site. <br />Development of the thicker coal bodies has occurred north of this site, relatively close to Grand Junction and in some areas <br />south ofthis site, near the Deity County line. These areas were worked prior to the first World War and had been abandoned <br />for many years. <br />No other known, economic deposits of petroleum, other potential quarry rocks or minerals are known to exist in this area. <br />GEOLOGIC IiAZARD„s <br />In general, this site in itself does not appear to contain any geologic hazards. The underlying clays of the Mancos Shale <br />Formation exhibit expansive characteristics but, expansive soils should not affect the gravel extraction operation. <br />The side slopes offofthis ridge, to the north and south are moderately steep. These side slopes are complicated by the Smith <br />irrigation ditch. This unlined irrigation ditch is in use primarily in the spring and early summer <br />months. Some areas of soil creep and slope failure complex features are evident on the north slope, below this proposed <br />gravel extraction pit. Less prominent slope failure features are present on the south facing sl <br />In its se1? the gravel extraction ope, overlooking Indian Creek. <br />operation on this property should not affect the stability of these slopes, either in a positive <br />or negative manner. The primary mechanism affecting these slope failures is the 1 <br />age, whether intentional or <br />uninteattional, from Smith Ditch. It is recommended that high banks or slopes not be constructed or allowed to remain <br />immediately above Smith Ditch. It would be advantageous, near the end of the gravel extru ctmg operation, to cut back any <br />banks on the north, west and east sides of the proposed gravel pit. The purpose of cutting these banks back would be to, <br />where possible, remove the weight of the gravel and soil from above the ditch, aiding in long term stability of these slopes. <br />It is believed that all pertinent points, as related to the Geologic Characteristics, which may significantly affect the proposed <br />development, have been addressed. If any further questions arise or if GRAND JUNCTION LINCOLN-DeVORE can be, <br />of any further service, please do not hesitate to contact this office at any time. <br />Respectfully submitted, <br />GRAND JUNCTION <br />LINCOLN-DeVORE, INC. <br />by: Edward M. Morris PE <br />Engineering Geologist <br />GJLD Job # 38222-GJ