Report on the geology of the Henry mountains |
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Aquarius Plateau Aubrey Sandstone bad-land beds Blue Gate Sandstone Blue Gate Shale Bowl Creek cañons carved channel Colorado Colorado River condition corrasion cover crest Cretaceous curve débris declivity degradation density deposition depth detritus dikes dikes and sheets Dirty Devil Dirty Devil River displacements dome drainage lines drainage system Elk Mountains erosion eruptive fault fissure Flaming Gorge shale flank flood-plains flow friction Geology Gray Cliff Sandstone greater hard Henry Mountains Henry's Fork conglomerate igneous rocks intrusive Jukes Jura-Trias laccolite lake lava less limit load masses Masuk Sandstone miles monoclinal Mount Ellen Mount Ellsworth Mount Hillers Mount Holmes Mount Pennell outcrops planation Plateau porphyritic portion region resistance River Scrope sculpture sedimentary sediments Shinarump Shale Sierra slopes spur stereogram strata stream structure summit surface Tertiary tion trachyte transportation truncated Tununk sandstone Tununk Shale uplift upper zone valley velocity Vermilion Cliff Sandstone Waterpocket flexure waterways weathering
Popular passages
Page 98 - He continues: If the strata had experienced anterior displacements so as to be inclined, folded, and faulted, a symmetrical growth of laccolites would have been impossible, and the mountains would not have yielded a knowledge of the type form. But the type form being known, it is to be anticipated that in disturbed regions aberrant forms will be recognized and referred to the type.
Page 101 - Wherever the two are combined, the superior efficiency of the latter is evident, and in all fields of rapid corrasion the part played by solution is so small that it may be disregarded. The mechanical wear of streams is performed by the aid of hard mineral fragments which are carried along by the current. The effective force is that of the current; the tools are mud, sand, and bowlders. The most important of them is sand; it is chiefly by the impact and friction of grains of sand that the rocky beds...
Page 106 - A stream of water flowing down its bed expends an amount of energy that is measured by the quantity of water and the vertical distance through which it descends. If there were no friction of the water upon its channel the velocity of the current would continually increase; but if, as is the usual case, there is no increase of velocity, then the whole of the energy is consumed in friction.
Page 21 - The lava of the Henry Mountains behaved differently. Instead of rising through all the beds of the earth's crust, it stopped at a lower horizon, insinuated itself between two strata, and opened for itself a chamber by lifting all the superior beds. In this chamber it congealed, forming a massive body of trap.
Page 127 - ... ceases when the load equals the capacity for transportation. Whenever the load reduces the downward corrasion to little or nothing, lateral corrasion becomes relatively and actually of importance. The first result of the wearing of the walls of a stream's channel is the formation of a flood-plain. As an effect of momentum the current is always swiftest along the outside of a curve of the channel, and it is there that the wearing is performed; while at the inner side of the curve the current is...
Page 103 - For not only does the bottom receive more blows in proportion as the quantity of transient detritus increases, but the blows acquire greater force from the accelerated current, and from the greater size of the moving fragments. It is necessary however to distinguish the ability to corrade from the rate of corrasion, which will be seen further on to depend largely on other conditions. Weathering is not directly influenced by slope, but it is reached indirectly through transportation. Solution and...
Page 124 - ... declivity. Every slope is a member of a series, receiving the water and the waste of the slope above it, and discharging its own water and waste upon the slope below. If one member of the series is eroded with exceptional rapidity, two things immediately result: first, the member above has its level of discharge lowered, and its rate of erosion is thereby increased ; and second, the member below, being clogged by an exceptional load of detritus, has its rate of erosion diminished. The acceleration...
Page 95 - The station of the laccolite being decided, the first step in its formation is the intrusion along a parting of strata, of a thin sheet of lava, which spreads until it has an area adequate, on the principle of the hydrostatic press, to the deformation of the covering strata. The spreading sheet always extends...
Page 109 - And also, the total energy is equal to the energy spent in friction, plus the energy spent in transportation. Whence it follows, that if a stream change its quantity of water without changing its velocity or other accidents, the total energy will change at the same rate as the quantity of water, the energy spent in friction will change at a less rate, and the energy remaining for transportation will change at a greater rate.
Page 21 - ... faithfully, by its curvature, the form of the body it covers. Associated with the laccolites of the Henry Mountains are sheets and dikes. The term sheet will be applied in this report to broad, thin, stratified bodies of trap, which have been intruded along the partings between sedimentary strata, and conform with the inclosing strata in dip. Dikes differ from sheets in that they intersect the sedimentary strata at greater or less angles, occupying fissures produced by the rupture of the strata....