Page:The Journal of geology (IA journalofgeology11893univ).pdf/203

De la Beche (Geology, 3d edition, 1833) carries out the system more completely, calling the first, or superior order, Supercretaceous group, and applying the terms Cretaceous, Oölitic and Red sandstone to three groups into which he divides the second order, and giving the third the name Carboniferous group. Below these he recognizes Werner's Grauwacke group, for what was the lower part of the original Uebergangsgebirge of his earlier classification, and below this were the inferior stratified or non-fossiliferous rocks, and the unstratified rocks. All of the names, it will be observed, are names indicative of mineral characters. If we turn back to the year 1817 we find the same Wernerian system applied to the classification of North American rocks by William Maclure (Observations on the Geology of the United States of America, Philadelphia, 1817). The author writes: "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 relative position of the different series of rocks." (Observations, etc., p. 28). The classification there set forth is as follows (in the order from below upwards):