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<br />-5."7 <br /> <br />.' <br /> <br />with Mesa Verde strata cropping out high on Gallo Bluff and in a narrow <br /> <br />band south of the Crystal River. The Mesa Verde also probably subcrops <br /> <br />beneath the extensive talus debris north of the Crystal River in the <br /> <br />vicinity of the landing strip. There is intensive minor faulting and <br /> <br />shattering of the Cretaceous strata in Gallo Bluff - a condition which <br /> <br />presumably extends under the landslide, colluvial, mudflow, and other <br /> <br />surficial deposits which mask the bedrock surface over most of the area <br /> <br />between Gallo Bluff and the main mass of Treasure Mountain Dome east of <br /> <br />Marble. Porphyritic intrusive rocks occur within the~rea,on both <br /> <br />sides of the Crystal River west of Marble in the vicinity of the landing <br />strip. These outcrops consist of the adjacent synclinal limbs of the <br /> <br />Raspberry Creek Phacolith. Other intrusive igneous rocks occur in the <br /> <br />upper reaches of Carbonate Creek, along with Pennsylvanian sedimentary <br /> <br />strata. These rocks have been thrust over Cretaceous beds along the <br /> <br />Elk Range Thrust Zone. Igneous rocks of minor importance occur as oc- <br /> <br />casional dikes cutting the Cretaceous strata. <br /> <br />Surficial deposits of the area, with which much of the report is <br /> <br />concerned, are also complex but are much younger, being of Pleistocene <br /> <br />and Recent age. These deposits consist of residual soils formed on <br /> <br />Mancos Shale, talus and other colluvial soils, landslide and mudflow <br /> <br />deposits, and older morainal material which occurs as discontinuous <br /> <br />deposits mostly on the higher slopes. <br />Geomorphic evolution of the area has been affected by rock type <br /> <br />and structure, by multiple glaciation during Pleistocene time, and <br /> <br />finally by intensive fluvial action and vigorous mass wasting. The <br /> <br />vigorous fluvial and mass wasting processes which have dramatically <br /> <br />modified the area since the last glaciation are continuing, and are <br /> <br />.. <br />