The Geology Of A Portion Of The San Jose Hills PDF Download

Purchase of this book includes free trial access to www.million-books.com where you can read more than a million books for free. This is an OCR edition with typos. Excerpt from book: is lacking, however, and faults are not indicated on the map. Another fault worthy of mention occurs in the Alum Rock Hills south of Alum Rock canyon and causes the Miocene beds to appear to underlie the Knoxville for a distance of ahout a mile and a half. 'This fault has a maximum possible throw of something like 6,000 feet, the donwthrow .being to the west. It is more than probable, however, that this figure is great- ly exaggerated by minor folds and which are not evident from the present exposures. Folding.- Anticlinal valleys and synclinal ridges is a general rule governing the relation of topography to geologic structure in the Mt. Hamilton Range. The portion of that range which lies within the San Jose quadrangle is no excep- tion to that rule. The aslient features of the folding lie in the general parallelism of the maJor folds to each other and to the lit. Hamilton Range as a whole, and in its frequent abruptness and intensity. The axes of the.principal known folds of the San Jose quadrangle 'are shown on the map, and the nature of the folds, on the structure section which accompany this paper. Detailed discussion of each of those, therefore, i? superfluous. 0ther than the low, wide oyncline which probably forms the Santa clara Valley, the principal maJor folding of the San Jose quadrangle occurs in Mission Ridge and the Alum Rock Hills. In structure. Mission Ridge is probably primarily a large normal syncline which has been buckled up near the axis. forming an overturned anticline within the syncline. This has the effect of producing a geosyncline consisting of a normal syncline as its most easterly fold, followed by an overturned anticline next west, which in turn is. followed (See structure sections AA andBB.). by an overturned synclin...