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<br /> <br />GLOSSARY <br /> <br />v <br /> <br />Granite. A visibly granular igneous rock of interlocking texture composed essentially of alka- <br />lic feldspar and quartz, commonly with a small percentage of mica and hornblende. Very <br />common in upper reaches of Big Thompson Canyon. <br />Granodiorite. A visibly granular igneous rock of interlocking texture similar to granite in gen- <br />eral appearance but with soda-lime feldspar predominant over alkalic feldspar in a ratio of <br />from 2:1 to 7:1 and with hornblende as the common mafic accessory mineral. <br />GrUB. An accumulation of waste consisting of angular, coarse-grained fragments resulting <br />from the granular disintegration of crystalline rocks, especially granite, generally in an arid <br />or semiarid region (Gary and others. 1972. p. 317t. <br />Hydrograph. A graph showing stage, discharge, velocity, or other property of water with re- <br />spect to time. <br />Inversion (Temperature inversion). A layer in the atmosphere where the temperature increases <br />with height. <br />Isotherm. A line of equal or constant temperature. <br />Knot (ktl. A rate of speed of 1 nautical mile per hour, equal to 1.105 miles per hour. Commonly <br />used to express wind speed. <br />Landslide. The downward and outward movement by falling and (or) sliding or flowing of <br />slope-forming materials composed of natural rock, soils, artificial fills, or combinations of <br />these materials. (See Varnes, 1958, p. 20; see also fig. C). <br /> <br /> <br />II <br /> <br />ill <br /> <br />N <br /> <br />FIGURE C.-Landslide types common along the east slope of the Front Range. From left to right: <br />J, rockfaU moves mostly by free fall, bounding, and rolling; II, slump by rotational slippage on <br />concave-upward shear surfaces; III, debris slide by complex internal adjustments of highly <br />deformed, sheared slide mass; IV, earthflow by displacements and velocities similar to those of <br />viscuous fluids (Varnes, 1958, pI. 1). Types A and Cwere prevalent in the Big Thompson Canyon <br />area. Small-scale slumping, type B, took place along riverbanks east of the mountains. Illustra- <br />tions by Natalie J. Miller, from Nilsen (19721. <br /> <br />Level of free convection. The level at which a parcel of air lifted dry adiabatically until satu. <br />rated, and moist adiabatically thereafter, would first become warmer than its surroundings. <br />Lifted condensation level. The level at which a parcel of moist air lifted adiabatically would <br />become saturated. <br />Lifted index. An index based on the difference lin oc) between the 500-millibar (mb) environ- <br />mental temperature and the temperature of a parcel of air lifted adiabatically from or near <br />the surface. <br />Mass wasting. A general term for the dislodgement and downslope transport of soil and rock <br />material under the direct application of gravitational body stresses. In contrast to other ero- <br />sion processes, the debris removed by mass wasting processes is not carried within, on, or <br />under another medium possessing contrasting properties. The mass strength properties of <br />the material being transported depend on the interaction of the soil and rock particles with <br />each other. It includes slow displacements such as creep and solifluction and rapid <br />movements, such as earthflows, rockslides, avalanches, and falls /Gary and others, 1972, <br />p,4341. <br />Metamorphic rock. Rock changed materially in composition or appearance, after consolida- <br />tion, by heat, pressure, or infilitrations at some depth in the Earth's crust below the surface <br />zone of weathering. <br /> <br />.\, <br />