Geologie von Deutschland und den angrenzenden Gebieten

Abstract

THIS part of the text elucidating Dr. Lepsius's well known geological map of Germany maintains a high level, and secures the acceptance of the book as a permanent work of reference. It is not so redolent of the country itself as is the great work on Austria-Hungary recently noticed in these columns (May 19, p. 49), but it embodies the results of extensive researches, and the individuality of the author is agreeably seen when he marshals and reviews the conclusions of those who have gone before him. The present section is of especial interest to students of metamorphic areas. The amphibolites and marbles of the “kristalline Grundlage im Erzgebirge” will recall many occurrences in our Scotch and Irish highlands. The description of the saturation of a schistose area by invading granite (p. 104), and the consequent origin of the gneissic massif of the Erzgebirge, will appeal to those who have sought to show that our own “Archaean” gneisses may often be of composite origin, and in places of post-Silurian age. The famous area of granulite in Saxony is dealt with from the point of view so long maintained, in other regions, by French geologists, to whom personal recognition is accorded (p. 172). Dynamic metamorphism is relegated to a relatively unimportant place, and the granulite is treated as a part of the Carboniferous granitic intrusion, making its way, under pressure of superincumbent layers, into a great dome of schists. The pyroxene-granulites and other variations arise from the absorption of diabases, quartzites, and so forth, into the invading mass. The observations of Callaway in Galway and Barrois in Brittany thus receive confirmation from the stronghold of the dynamometamorphic school.