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appear base basin beds belt Black California canyon character characteristic clays coal coast collections Colorado contain continued creek Cretaceous crystalline Dakota deep deposits Devonian east eastern elevation evidence exposed extended fact falls fault fauna feet figure fold formation fossils Geol Geological Survey glacier granite gravel Hall hills inches indicated iron kilometer known lake less lignite limestone locality looking lower marked Maryland material meters Michigan miles mount mountain nearly northern observed occur original pass Pennsylvania Photographed plain plate Pleistocene portion position Potomac present probably quarry railway range referred region relations Report represented river rocks sand sandstone schists sediments shales showing side slope Society species specimens stage station strata stream structure surface Tertiary thickness thrust tion upper valley volume western White York
Seite 505 - The Auditing Committee reported that the accounts of the Treasurer had been found correct, and the Society adopted the report. The Council submitted its report on the matter of the proper pronunciation of the name " Cordilleran," which had been referred to the Council at the Washington meeting, 1899.
Seite 358 - Virgilina district. 3. The rocks are pre-Cambrian in age and represent an area of ancient volcanics similar to others described as occurring along the Atlantic Coast region from eastern Canada to Georgia and Alabama and in the Lake Superior region. 4. The rocks are cut by numerous approximately parallel quartz veins which contain workable copper deposits. The veins have been described as true fissure veins, and the ore is glance and bornite, without chalcopyrite and pyrite.
Seite 358 - ... as indicated in the prevailing schistose structure, and the large development of the secondary minerals, chlorite, epidote and hornblende ; and smaller amounts of others. The alteration has advanced sufficiently far in the more schistose phase to destroy, in most cases, the original structure and minerals of the rock. 2. From structural, petrographic and chemical evidence, it is shown that the rocks are derived from an original andesite. The altered andesite is intimately associated with the...
Seite 122 - Freeport coal and its associated strata from the Pennsylvania line along their eastern outcrops across to the Kanawha valley. In this I was entirely successful, and the result is a complete confirmation of my original conclusion with reference to the horizon of the Upper Freeport coal on the Great Kanawha, namely, that it is the first one below the black-flint stratum, and hence this latter member belongs near the base of the...
Seite 117 - Not merely the earth's crust, but the whole of earth-knowledge is the subject of our research. To know all that can be known about our planet, this, and nothing less than this, is its aim and scope. From the morphological side geology inquires, not only into the existing form and structure of the earth, but also into the series of successive morphological states through which it has passed in a long and changeful development. Our science inquires also into the distribution of the earth in time and...
Seite 7 - ... monotonous plain which abuts against an east and west ridge known as the Douglas copper range. The north slope of this ridge is abrupt, and its summit is 100 to 300 feet above the plain. The plain is underlain by the Lake Superior sandstone in horizontal beds, and the ridge consists of lava flows dipping steeply toward the south. The sandstone in general is not firmly cemented and is easily eroded, while the traps or lava flows are much more resistant to erosion. The abrupt northward slope of...
Seite 302 - Montana, extends into southern Alberta and ends, and Livingston range, which, lying 8 to 15 miles west of the Lewis, becomes in Alberta the easternmost height of the Rockies. The features of adjacent districts are described so far as they bear on the main subject, the stratigraphy and structure of the Front ranges. Lewis and Livingston ranges consist of stratified rocks of Algonkian age, as determined on fossils which were found by Weller in the lowest...
Seite 186 - The flora of the Patuxent formation includes equiseta, ferns, cycads, conifers, monocotyledons, and a very few archaic dicotyledons, the coniferous and cycadean element being particularly strong. The known fauna of the Patuxent formation is limited to a single unio (Ward) and a fish (Fontaine).
Seite 358 - Watson states his conclusions'' as follows : "1. The rocks of the area here described have been greatly altered through pressure and chemical metamorphism, as indicated in the prevailing secondary schistose structure and the abundant development of the secondary minerals — chlorite, epidote, and hornblende — and small amounts of others. The alteration has advanced sufficiently far in the schistose phases to destroy in most cases the original structure and minerals of the rock. "2. From structural,...