Professional Paper - United States Geological Survey, Ausgaben 109-110The Survey, 1919 |
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50 feet Alaska alluvial Arctic Mountains Arctic Ocean aufeis bank Barter Island basalt beach beds blocks boulders camp canyon Cerro Gordo coast Colville cones Creek Dease and Simpson deposits depth diameter diorite drift erosion Eskimo evidence exposure fault fauna Flaxman Island forks formation formed fossils Franklin freezing frost GEOLOGICAL glacial glaciers granite gravels ground ice Herschel Island horizontal Hulahula ice wedges Ignek inches Inyo Range lake land layers Leffingwell limestone Lisburne locality lower mass meters miles moraines mound Mount Whitney native observed Okpilak Owens Valley Peak Point Barrow probably quartz monzonite quartzite Reef region ridges River rocks Romanzof Mountains Sadlerochit sand sandstone Schergin schist Schrader seen shaft shales shore Shublik Sierra Nevada slope snow station Stefánsson stream surface Survey tains temperature tion Triassic tundra U. S. Geol upland upper vertical west side winter writer
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Seite 8 - ... Canning River region, northern Alaska, by E. de K. Leffingwell. 1919. 251 pages, 35 plates, 33 text figures. Prior to the explorations whose results are here set forth the Canning River region of Arctic Alaska was practically unknown except as to its larger geographic features. The region as a whole presented an almost complete hiatus in the scientific knowledge of Alaska, and Mr. Leffingwell has performed a valuable service in mapping and describing its geography and geology. During the 10 years...
Seite 189 - ... Fourier's Solution stated. — If the temperature at any point of an infinite plane, in a solid extending infinitely in all directions, be subjected to a simple harmonic variation, the temperature throughout the solid on each side of this plane will follow everywhere according to the simple harmonic law, with epochs retarded equally, and with amplitudes diminished in a constant proportion for equal augmentations of distance. The retardation of epoch expressed in circular measure (arc divided...
Seite 156 - The ice, to the west and southwest, was as solid and compact, to all appearance, as so much land...
Seite 234 - Appendix, p. 600. peat, floating it in a state of semi-buoyancy above the frozen substratum of alluvium or peat so the ice may accumulate season after season, as long as there is a growing and buoyant equilibrium maintained between the annually thawed peaty superstratum and the constantly frozen substratum.
Seite 145 - Archean gathering grounds to the east poured westward through the gaps and passes in the eastern flanking ranges of the Rocky Mountains until it reached the barrier formed by the main axial range, when, being unable to pass this, it was deflected to the northwest in a stream from 1,500 to 2,000 feet deep down the valley of the Mackenzie and thence out to sea.
Seite 174 - ... seams. When first examined it was believed that they represented cracks which had been subsequently filled by material from the surface. Similar cracks are observed at the present time in many places where the melting of the ground ice allows settling and cracking of the deposit previously formed. In the light of more careful study, however, such an interpretation seems inadequate, for many of the seams taper off toward the top as well as toward the bottom, so that a connection with the surface...
Seite 90 - ... and form good cover ; it bears no fruit. The second is more abundant in the southern than in the northern part of the island ; its trunk is nearly the thickness of a man's arm, very crooked, never higher than three feet, and bears no fruit. The gruillera is the smallest of the three, growing close to the ground, and abundant all over the island; being easily ignited, it was chiefly used...
Seite 152 - ... the result of hydraulic pressure offers the best explanation. He believes that at the beginning of the arctic climate the ground became frozen progressively downward and formed am impervious layer over a tilted water-bearing stratum, giving rise to conditions favorable to artesian wells. Hydraulic pressure may have acted so slowly as to bulge up and fracture the frozen crust locally without any great outflow of water, or it may have occurred suddenly with a great outflow of water which carried...
Seite 149 - Here and there rounded hills one-half mile in diameter at the base rise 100 to 300 feet above the general surface of this plain. They are symmetrical in shape and, although irregularly distributed over the plain, suggest, when viewed from a distance, giant haystacks. None of these was examined at close range, but they are apparently gravel mounds similar to those near the mouth of the Colville...
Seite 234 - ... of moss under some of the circumstances where it is met with, especially on sloping surfaces such as Tyrrell describes for the Klondike region and which are common elsewhere in Alaska, is similar to a suggestion made by Lieutenant Belcher.