Bulletin of the Geological Society of America, Bind 20

Forsideomslag
The Society, 1910
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Side 406 - ... oceanic islands and not continental interiors, he showed that the extent and position of oceanic depressions have in a great degree determined the features of the land: that oceanic depression and continental elevation have both been in progress with mutual reaction from the beginning of the earth's refrigeration. The original V-shaped character of the North American continent he showed to be due to the forces acting from the two oceans.
Side 406 - ... and sea. While it is generally supposed that the extent of the continental areas at the beginning of Paleozoic time was small, forming islands, Walcott is inclined to the belief that it was very considerable, stating : The continent was larger at the beginning of the Cambrian period than during any epoch of Paleozoic time, and probably not until the development of the great fresh-water lakes of the Lower Mesozoic was there such a broad expanse of land upon the continental platform between the...
Side 37 - The rocks of the cataracts of the River Madeira and the adjoining portions of the Beni and Mamori : Dr.
Side 459 - ... No species in any way characteristic of the Lower Coal Measures or the Allegheny formation remains. On the other hand, the ferns, either as individual species or as phases of species having wide range, are clearly indicative of a stage at least very high in the Upper Carboniferous (Pennsylvanian). Nearly all the species have been reported from either the Permian of Europe or the Dunkard formation of the United States, though, with the possible exception of Pecopteris Newberriana, none are distinctly...
Side 404 - containing several disconnected longitudinal folds high enough to affect the direction of currents and consequently the character of the sediments, and, in a smaller degree, faunal distribution." The variegated marbles are in the western or "Knoxville trough
Side 38 - Chemist ; accompanied by a Description of the most Interesting American Gems, and Ornamental and Architectural Materials, by Dr.
Side 156 - ... by .existing rivers in about 600,000 years. Since the sulphate is being rapidly decomposed by lime-secreting organisms and converted into deposited carbonate, it is probable that much more than 600,000 years have elapsed since the bathybial fishes and other scavengers colonized the general sea floor to depths of 2,500 fathoms. The test case of the Black sea shows that the present content of calcium sulphate in ocean water would be largely and rapidly diminished if the scavenging system were not...
Side 406 - Dana81 determined this land as the "Central-Newfoundland range," and described it as "extending over a broad region east of the Exploits River valley, to the east side of Exploits bay." Novascotia may be used for the province by this name, the northwestern portion of which was variously overlapped by the Acadian trough. Dana included this land in his Acadian range, and it is his "Nova Scotia protaxis."82 Newbrunsvickia represents a small subelement at the northeast of the province of New Brunswick.
Side 11 - Pioneering in South Brazil; three years of forest and prairie life in the province of Parana. Map and Illustrations. 2 vols. Crown Svo. 24>.
Side 191 - They intersected the strata above and below them after the latter imd become hard and brittle. (5) They may be observed in direct continuity with dikes. (6) They pass from one horizon to another. (7) The bottom of the sedimentary strata above them, wherever it is observable, is a freshly ruptured surface. (8) Apophyses of the trap pass from the main sheet into the cracks of the slate above and below. (9) The trap sheets, particularly at the upper contact, hold included fragments of the overlying...

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