Projekt: Bestände der Universitätsbibliothek Freiberg
LDP: UB Freiberg Druckschriften
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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
86 INTERNAL STRUCTURE. in many important features with that in the fketz-trap. Thus, bafalt is frequently porphyritic, and ‘fometimes amygdaloidal, which latter, how ever, is but a rare occurrence in porphyry. Fur ther, the columnar, globular, and tabular ftructure is nearly the fame in both. It contains very little mechanical depofition, and when it does occur, it is almoft entirely compofed of maffes of rocks; ne ver any petrifaction, which was to be expeCted, becaufe this formation was formed at a far earlier period than the neweft floetz-trap, when the level of the water was incomparably higher, and when no animals or vegetables exifted. This formation alfo contains little or no carbonaceous matter, which we found to be fo abundant in the neweft floetz-trap formation. Thefe obfervations are fufficient to fhew us how nearly thefe two formations are allied, and how admirably their ftruCture correfponds, and is illuf- trative of their mode of formation. lnvejligation of the Contents of the Water of the Globe, at different Periods. 46. This fubjeCt is highly interefting. It points out to us in legible characters the alterations which the ocean experienced during its gradual diminu tion* and affords a very interefting picture of the internal ftruCture and furface of the earth during the different periods of its formation. When