Observations on the Geology of the United States of America: With Some Remarks on the Effect Produced on the Nature and Fertility of Soils, by the Decomposition of the Different Classes of Rocks; and an Application to the Fertility of Every State in the Union, in Reference to the Accompanying Geological Map ...author, 1817 - 127 páginas |
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Observations on the Geology of the United States of America William Maclure Vista de fragmentos - 1962 |
Observations on the Geology of the United States of America William Maclure Vista de fragmentos - 1962 |
Términos y frases comunes
aggregates Alleghany Alleghany mountains alluvial alluvial formation banks basin beds chrystalline chrystals classes of rocks climate coal Connecticut river consists contain covered decompose decomposition Delaware depositions distance earth east side edge Europe extensive favourable feldspar gneiss granite grey wacke slate gypsum heat horizontal hornblende hornblende rocks Hudson Hudson river iron island Lake Champlain Lake Ontario land lime limestone luvial manure masses mation mica mica slate miles Mississippi moisture moun Nature and Fertility navigation North Carolina north-west occupies old red sandstone oldest red sandstone particles perhaps places primitive formation primitive rocks probable produce pyrites quantity quartz range of mountains rich and fertile ridge rivers sand and gravel schistose secondary limestone secondary rocks sition situation south-east south-west Stony mountains strata stratification substances surface tains thin tion tive tolerable soil transition and secondary transition class transition formation vallies vegetable mould washed whole Yadkin river
Pasajes populares
Página iii - All inquiry into the nature and properties of rocks, or the relative situation they occupy on the surface of the earth, has been much neglected. It is only since a few years that it has been thought worth the attention of either the learned or unlearned ; and even now a great proportion of both treat such investigations with contempt, as beneath their notice. Why mankind...
Página 51 - The outline of the mountains of this formation is almost a straight line, with few interruptions, bounding long parallel ridges of nearly the same height, declining gently towards the side, where the stratification dips from the horizon, and more precipitous on the opposite side, where the edge of the stratum breaks out to the day.
Página iv - ... beneath their notice. Why mankind should have so long neglected to acquire knowledge so useful to the progress of civilization — why the substances over which they have been daily stumbling, and without whose aid they could not exercise any one art or profession, should be the last to occupy their attention — is one of those problems perhaps only to be solved by an analysis of the nature and origin of the power of the few over the many.
Página 53 - Susquehannah rivers; and a large body of alum slate on Jackson's river, Virginia; many powerful veins of the sulphate of barytes cross it in different places; granular, as that near Fincastle, or slaty, as that in Buncomb county, North Carolina. Iron and lead have as yet been the principal metals found in this formation ; the lead in the form of galena, in clusters, or what the Germans call Stockwerk, as at the lead mines on New river, Wyeth county, Virginia; the iron disseminated in pyrites, hematitic...
Página 56 - Pensylvania, with some interruption, all the way to the waters of the Tombigbee, accompanied by the usual attendants, slaty clay and freestone, with vegetable impressions, &c. ; but, in no instance that I have seen or heard of, covered by, or alternating with, any rock resembling basalt ; or indeed any of those called the newest floetz trap formation.
Página 32 - ... magnetic iron ore, from eight to twelve feet thick, wrought in Franconia, near the White Hills, New Hampshire; that there is a similar bed in the direction of the stratification, six miles north-east of Philipstown on the Hudson river; and, still following the direction of the stratification, that the same ore occupies a bed nearly of the same thickness at Ringwood, Mount Pleasant, and Suckusanny, in New Jersey; losing itself, as it approaches the end of the primitive ridge, near Blackwater —...
Página 28 - Necessity dictates the adoption of some system so far as respects the classification and arrangement of names. The Wernerian seems to be the most suitable, first, because it is the most perfect and extensive in its general outlines; and secondly, the nature and relative situation of the minerals in the United States, whilst they are certainly the most extensive of any field yet examined, may perhaps be found the most correct elucidation of the general accuracy of that theory, so far as respects the...
Página 14 - The short period of time that mankind seem to have been capable of correct observation, and the minute segment of the immense circle of nature's operations, that has revolved during the comparatively short period, renders all speculations on the origin of the crust of the earth mere conjectures, founded on distant and obscure analogy. Were it possible to separate this metaphysical part from the collection and classification of facts, the truth and accuracy of observation would be much augmented,...
Página 52 - ... in a compact petrosiliceous cement, and a great variety of other rocks, which, from their composition and situation, cannot be classed but with the transition.
Página 31 - Hudson's river, constitutes the highest mountains, while the little transition and secondary that is found, occupy the low grounds. To the south of the Delaware, the primitive is the first rock after the alluvial formation of the ocean — the lowest step of the stair which gradually rises through the different formations to the top of the Alleghany. To the eastward of the state of New York, the stratification runs nearly north and south, and generally dips to the east, looking up to the White Hills,...