Bulletin of the Geological Society of America, المجلد 4

الغلاف الأمامي
Geological Society of America, 1893
Vols. 1-44 include Proceedings of the annual meeting, 1889-1933, later published separately.
 

المحتوى

طبعات أخرى - عرض جميع المقتطفات

عبارات ومصطلحات مألوفة

مقاطع مشهورة

الصفحة 338 - Sedesholm. of the contact between them, as justly observed by Barlow.* These features have been so clearly and precisely described by Lawson in his official reports that it is unnecessary to repeat them here ; suffice it to say that I have found his description to apply to all the contacts that I have observed in the portions of Rainy River district not reported on by him.
الصفحة 39 - ... the power of any spring is in the same proportion with the tension thereof: that is, if one power stretch or bend it one space, two will bend it two, and three will bend it three, and so forward.
الصفحة 395 - Reports of explorations and surveys to ascertain the most practicable and economical route for a railroad from the Mississippi river to the Pacific Ocean. Volume VIII. Washington: .... 1857.
الصفحة 395 - Many observations on the coal seams and general geology of this country are recorded, to whose accuracy and importance later and fuller reports have given ample confirmation. The results of this expedition were not made public until 1876, owing in part at least to the demoralization of the war. They then appeared under the title, " Report of the Exploring Expedition from Santa Fe to the junction of the Grand and the Green Rivers,
الصفحة 190 - In our ignorance of subterranean forces we should use such a priori considerations only as a means for the suggestion of hypotheses. As they have doubtless served to promote the theory of continental growth, they should also be permitted to indicate the possibility of continental retrogradation. Summary. — The problems of the continents have been touched to-day so briefly that a summary is almost superfluous. The doctrine of isostasy, though holding a leading position, has not fully supplanted...
الصفحة 187 - ... essentially conservative. Neither is it easy to believe that the two margins of the plains have differed, since the, Cretaceous, to the extent of one mile in their radial contraction due to secular cooling of the globe; nor is it easy, at least for the disciple of isostasy, to believe that such a change can have resulted from the localization of deformation consequent on the slowing of the earth's rotation. Each of these processes may have been concerned, but I conceive that the essential factor...
الصفحة 202 - Muir glacier, imply a short rather than a long duration of the Ice age. This conclusion is further affirmed by the continuance of the same species of the marine molluscan faunas from the beginning of the Glacial period to its end and to the present day.
الصفحة 77 - Llandeilo flags were (bund in three distinct forms, arising from the distortion taking place in a longitudinal, transverse, or oblique direction ; this seemed to be the result of a creeping movement of the particles of the rock along the planes of cleavage, the effect of which was to roll them forward, in a direction always uniform, over the same tract of country...
الصفحة 350 - ... dotted lines will occur. The same description of arrangement will be found where the whole ground of the rock is white instead of red, and then the red feldspar will occasionally constitute streaks. There is no end to the diversity of arrangement in which the minerals and the colors will be observed, but there is a never-failing constancy in respect to their parallelism, which, however, though never absent, is sometimes obscure.
الصفحة 183 - The problem of the origin of the continents remains almost untouched. Those who have propounded theories for the formation of mountain ranges have sometimes included continents also, but as a rule without adequate adaptation to the special conditions of the continental problem. So far as I am aware, the subject has been seriously attacked only by our second president.

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