Reviews — Geological Map 0/ Ca2)e Colony. 563 



geology of Armenia system by system. The volume closes with 

 a note by Dr. Bonney on rocks collected by Mr. Lynch in 1893, 

 a bibliography, and voluminous index. On the value of the two last 

 items we need not enlarge. 



In an introductory chapter Dr. Oswald discusses the orography 

 of the Asiatic continent, and calls attention to the Armenian plateau 

 as the natural bridge between Central Asia and Southern Europe, 

 illustrating his remarks with maps. He regards the chief eras of 

 mountain folding in Armenia as belonging to the Lower Permian, 

 ante-Tithonian, and post-Oligocene periods, and at each time the 

 pressure came from the south (the Arabian tableland), while the 

 northern limit to all this folding was formed by the great granitic 

 ' horst ' of the Meschic Mountains. The lines of fracture are 

 carefully explained in the text and on the maps, and the author 

 points out that the position of the numerous volcanos of Armenia is 

 by no means fortuitous, but on the contrary they have invariably 

 arisen along these lines, while those volcanos which occur at points 

 of intersection are proportionately larger. Gently folded Miocene 

 limestones are characteristic of the plateau, but never occur in the 

 border ranges ; on the other hand, while metamorphic schists are 

 characteristic of the Taurus, they occur only quite exceptionally in 

 the plateau region. The depressions along the lines of fracture 

 became filled by lake-deposits during Pliocene and Pleistocene times, 

 and lavas and tuffs of contemporary volcanos became interbedded 

 with the later deposits, and assisted in levelling the pre-existing 

 inequalities of the ground. 



Special attention has been paid to the petrology, and numerous 

 long footnotes describe in detail the rocks met with by the author in 

 his journey. The book is remarkably free from misprints, is full of 

 topographical detail, and is the first attempt which has been made to 

 write a systematic geological history of an interesting portion of the 

 world. One can only regret that Dr. Oswald, has (owing to the 

 extreme difficulties under which his volume has been produced) 

 printed but one hundred copies, for it is quite evident that his book 

 must remain for a considerable period the chief work of reference on. 

 the geology of Armenia. C. D. S. 



IL — Geological Map of the Colony of the Cape of Good 

 Hope. Sheet I. Published by the Geological Commission, 

 1906. Geology : by A. W. Rogers, E. H. L. Schwarz, and 

 A. L. Du ToiT. 



ri^HE Geological Commission of Cape Colony has now been at 

 X work for over ten years. Daring this period it has issued 

 valuable Annual Reports with small scale maps illustrating the 

 areas surveyed. The present map, then, can be regarded as the 

 outcome of years of arduous field-work, undertaken b}' the Director, 

 Mr. A. W. Rogers, with the assistance of Messrs. E. H. L. Schwarz 

 and A. L. Du Toit. The manner in which this survey has always 

 been carried on has led us to expect that the final map would be 



