Die klimatischen Verhöltnisse der geologischen Vorzeit vom Praecambrium an bis zur Jetztzeit und ihr Einfluss auf die Entivickelung der Haupttypen des Tier- und Pflanzenreiches

Abstract

THIS treatise commences with a consideration of the views of different authors upon the early evolution of the earth. Of the rocks in the earth's crust, Olivine rock (Dunite) is considered by the author to be the most primitive, its formation having taken place before the condensation of the water-vapour contained in the very earliest atmosphere. The gneisses, however, were formed after such condensation had occurred. The beginnings of organic life were present in the original atmosphere of water-vapour, but the author doubts the view of Arrhenius that the early spores could have reached the earth from other heavenly bodies. The period between the Upper Cambrian and Purbeckian was one of little rain, the existence of salt deposits in the early formations at various places widely separated from one another, and the complete absence of real freshwater calcareous deposits prior to the Jurassic being cited as evidence in support of that view. In this connection the interesting questions are propounded: Why have no remains older than the fauna of late Tertiary or diluvial times been found in the caves of Devonian, Carboniferous, Triassic, and Jurassic limestones? Why did cave formation thus probably begin first in Tertiary times? Die klimatischen Verholtnisse der geologischen Vorzeit vom Praecambrium an bis zur Jetztzeit und ihr Einfluss auf die Entivickelung der Haupttypen des Tier- und Pflanzenreiches. By Dr. Emil Carthaus. Pp. v + 256. (Berlin: R. Friedlander und Sohn, 1910.) Price 8 marks.