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
INTERNAL STRUCTURE. the characteriftic pofition of the ftrata in the dif ferent members of this feries of formations, and of their relations to the exterior of the earth. This will be confidered particularly afterwards. At prefent we fhall only mention the highly elevated level of the limeftone in gneifs, contrafted with the low fituation of chalk and calc-tuff. 2. Slate Formation-Suite. This is a very extenfive feries of forma tions # . The Limeftone Series is compofed only of limeftone, and a fingle earth as its principal con- ftituent part. In the feries of Clay-flate Forma tions, on the contrary, different earths have united together, to form the rocks we {hall now mention. Silica, Alumina and Magnefia, but particularly the two latter, are the moft charaderiftic earths be longing to this fuite of formations. We fhall be gin the defcription with that member of the feries which may be confidered as a central point from which the others diverge, and which gives the name to the whole feries. This is Clay-flate. It is evident, that the oldeft Clay-flate muft border on the neweft Mica-flate ; and the neweft, on Traniition- flate. The oldeft Clay-flate has more luftre than the newer, and is even flightly micaceous, fa that it * If we would judge of the propriety of the name given to this feries, from its extreme members, it would appear very unappropriate. To judge rightly, we muft confi- der it in the whole or on the great fcale.