Geology of Monadnock Mountain, New Hampshire

Abstract

GEOLOGY OF MONADNOCK MOUNTAIN, NEW HAMPSHIRE.' CONTENTS. A. DESCRIPTION OF MONADNOCK. B. ROCKS OF MONADNOCK AREA. I. Andalusite schist. 2. Fibrolite schist. 3. Quartzose mica schist. 4. Rusty, graphitic mica schist. 5. Granite. a) Occurrence in lobes. b) Inclusions in. c) Alternation of, with schist along the border. d) Pegmatite in. e) Relation of, to schist. C. AGE OF THESE ROCKS. D. ATTITUDE OF THE SCHIST IN THE MOUNTAIN. E. JOINTING OF THE SCHIST. F. Two PERIODS OF METAMORPHISM INDICATED IN THE SCHIST. G. REASON FOR THE SURVIVAL OF THIS MOUNTAIN. MONADNOCK, situated in southern New Hampshire, is of special interest to geologists because it was selected by Professor Davis as atype of the isolated, residuary peaks that may be found rising above a base-leveled land surface. This mountain rises 3,1662 feet above mean sea-level and about 2,000 feet above the surrounding peneplain, the plateau of southern New England. At the first glance the mountain may appear, from its representation on the Topographic Map, as a regular, single peak; but, on 'Monadlock is considered in the Geology of New Hampshire, Vol. II, pp. 24, 5o3, 639. Tlis area, with a section through the mountain, is represented on the fourth sheet of thegeological map in the atlas accompanying the same. 2 From he Topographic Map of the U. S. Geological Survey. Vol. XII, No.. i