Projekt: Bestände der Universitätsbibliothek Freiberg
LDP: UB Freiberg Druckschriften
Strukturtyp
Band
Parlamentsperiode
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Wahlperiode
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Titel
Chap. V. Theory Of The Diminuation Of The Waters Of The Globe. - Description Of Overlying Formations. - An Investigation Of The Contents Of The Original Waters Of The Globe During The Different Periods Of The Earth's Formation. - The Division Of Rocks Into Five Great Classes
84 INTERNAL STRUCTURE. that the coarfeft are undermoft ; but above, we have the fineft mechanical and the coarfeft che mical depofitions, as clay and wacke. Bafalt, which lies immediately over the wacke, is to he confidered as a coarfe chemical precipitate, having an earthy afped and no luftre, and has probably been precipitated from an agitated fo- lution. Laftly, Porphyry-flate, Greyftone and Greenftone are to be confidered as precipitates from a ftate of complete chemical folution. They pafs into each other; and greenftone, which is ufu- ally the uppermoft, is the raoft cryftalline. It is evident from the nature and pofition of thefe rocks, that they have been formed by a vaft deluge. The water appears to have rifen rapidly ; again to' have become more calm; and, during the period of its fettling, to have depofited the different rocks of this formation ; and, laftly, to have retired to its former level with confiderable rapidity. During the fettling of the Water, as we have juft mentioned, the different rocks appear to have been formed, and the broken ftratification, which is fo chara&eriftic for this formation, partly by the ra pid retiring of the water. The heaps of trees, the beds of gravel, fand and clay, and their more fre quent occurrence in low than high fituations, their conftant occurrence in the lower parts of the for mation, are evident proofs of the rapid and tu multuous