Report of the State Geologist on the Mineral Industries and Geology of Vermont, Volume 4 |
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75 inch abundant Adirondacks Alburg amphibolite Apeibopsis appears Aristolochites asbestos Barre beds Beekmantown Belvidere Belvidere Mountain Black River boulders Brandon lignite Carpel Carpolithes Champlain Chazy clay color copper Cutting Plant deposits diameter east East Barre exposure feet thick figure fossils Fruit genus Geologist Geology of Vermont glacial Grand Isle granite Green Mountain Hitchcock inches thick island Isle La Motte Jour Lake lamottense layers Length Lesquereux less lignite limestone Lowell LXXIX LXXVI LXXXI Maclurea Marble Company mass miles mineral Monocarpellites Montpelier Museum n. s. Fig nearly North Hero Northfield Nyssa oval places Plate LXXX Point Professor quarry quartz Report ribs rock Rutland SAPINDOIDES schists Seely seen serpentine shale shaly shore shows side Slate species specimens stone strata striae Stromatocerium summit surface thin Trenton Tricarpellites Utica valley vein Width Woodbury
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Page 78 - Lawrence on the other, swept around the Adirondacks and entered the Mohawk valley at either extremity, while a feebler current, at the height of glaciation, probably passed over the Adirondacks and gave to the whole a southerly trend.
Page 7 - The personal work of the principal was directed to ascertaining the character and limits of the geological formations. Six thousand specimens were collected and a first annual report on the Geology of the State of Vermont, a paper of 92 pages, was presented. A busy year, that of 1846, followed. A map of the surface rocks was projected, several sections were worked out, all the counties of the state were visited and in some cases revisited, drawings for future illustrations made, specimens of fossils,...
Page 26 - ... exposure. The final change gives the familiar yellows and browns of a decomposed ferruginous rock. In this stock the rapid change from gray to green was observed only in phase /, as exposed on the north and northwest slopes of the mountain. Examination quickly showed that the color change of the rock is conditioned by the feldspar and that it is altogether a superficial phenomenon, taking place only where the air has access to the mineral. The question has naturally arisen as to the cause of...
Page 10 - From such opportunities for collection and having the gift of making accumulations it is not strange that the Museum under the charge of professor Adams took on a unique character and large proportions. Professor Hovey of the chair of physics had accumulated what may be considered the nucleus for the marvel that crystallized around it. A marvel it was, the hundreds and thousands of specimens grouped as to relationship and bearing a peculiar personality by the labelling in the beautiful handwriting...
Page 153 - They were converted into brown coal, and retained exactly fheir original shape and markings Early in the Spring of 1852 I visited Brandon, and found that the fruits were obtained from a bed of brown coal connected with the white clays and brown hematite of that place. I perceived at once that an interesting field was open before me ; and ever since I have been endeavoring to explore it. Great difficulties presented themselves, and I Ьате resorted to several gentlemen, both in this country and...
Page 26 - The rock of the Windsor quarry contains an important accessory not recognized in any other part of the syenite stock. It occurs in the form of elongated anhedral grains, either independent or associated as irregular intergrowths with the hornblende. In the hand specimen the mineral can be readily made out by its black color, waxy to lustrous appearance, and by the presence of only one good cleavage. In many cases the individuals are as much as half a centimeter long. The most striking microscopic...
Page 9 - ... This he entered with the same enthusiasm that had characterized his work in Middlebury, and the wider border, the mountains and valleys of Vermont. Here at Amherst as at Middlebury be put his fashioning hand on the Museum of Natural History to which he transmitted his personal collections accumulated in the Vermont survey. His more especial original study was in connection with the class Mollusca. The shells of Central America and the West Indies received his careful attention, and in pursuance...
Page 62 - The deposits of the Vermont copper belt occur as lenticular masses in foliated micaceous schists. They therefore simulate the type known as bedded deposits, being apparently entirely conformable to the schistosity of the inclosing rocks. The outcrops are generally concealed, however, except where the bed is exposed by mining operations. The ore forms lenses...
Page 62 - ... bands can be traced for long distances, although the exposures are not always satisfactory. At Copperfield the general foliation is north and south, with a dip of 25° to 30° E., but the structure is in general that of a broad anticlinal fold, the detailed structure showing close folding and puckering of the softer, more schistose beds, so that no single band can be followed for a long distance. The rocks when so folded contain many intercalated masses of quartz, occupying the crests of the...
Page 26 - ... are doubtless those which are to be seen in the large columns of the library building at Columbia University, New York City. The rock, as represented in the quarry, is a handsome, dark-green syenite, in this place characterized by medium to coarse grain and a typical eugranitic structure (spec. 42) ; elsewhere this phase grades into one possessing a trachytic structure. It is a syenite with variable amounts of free quartz and a low percentage of colored constituents. Primary veins or flow streaks...