This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ... a third period of volcanic activity (Potosi Series). In connection with the formation of these materials there were intruded into the sedimentary rocks various dikes, sills, laccoliths, and irregular masses which are the deeper-seated equivalents of the surface volcanics. On the flanks of the Needle ...
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This historic book may have numerous typos and missing text. Purchasers can usually download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1911 edition. Excerpt: ... a third period of volcanic activity (Potosi Series). In connection with the formation of these materials there were intruded into the sedimentary rocks various dikes, sills, laccoliths, and irregular masses which are the deeper-seated equivalents of the surface volcanics. On the flanks of the Needle Mountains dome a simple consequent drainage was developed during the doming period. The southern flanks Fig. 129.--Mount Wilson group in background. Looking down Howard Creek from south of Ophir Pass. of the dome were not covered with volcanic material and the consequent drainage developed on these slopes was not affected by volcanic action. The northern slopes of the domes, on the other hand, were affected by volcanic outpourings and the drainage greatly modified. After the last great eruptions the streams proceeded to dissect the surface deeply. The consequence of further uplift of the region and resulting deep dissection has been the formation of a confusing variety of slopes in intimate relation to the detailed geologic structure. Within short distances of each other one may find (1) ancient granites, (2) sedimentaries of more recent origin, (3) Tertiary conglomerates, and (4) more recent volcanic accumulations. The development of slopes upon these varied rocks has naturally been very complex and few generalizations may be applied to individual mountains or to the group as a whole. GLACIAL FEATURES A phase of the recent dissection of the region is associated with glaciation; the conditions prevailing in the Needle Mountains during the portion of the glacial period of which the best records are left were nearly the same as those which exist in the Alps at the present time. From the positions of well-defined terminal and lateral moraines it...
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Seller's Description:
Very Good. Ex-University Library, with usual stamps and markings. Card pocket on ffep. Interior pages are clean. Light shelf wear. Tape residue on back cover. Soiling to outer page edges. Year 1911. 759 pages. Oversize/Overweight, No International shipping.
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Seller's Description:
Good. Ex-library copy with usual markings. Cover and edges shows shelf wear. Few pages shows light soiling on bottom left. Very Clean Copy-Over 500, 000 Internet Orders Filled.
