432 Reviews — Baron Richthofen^s China. 



Jura. Mesozoic strata of a later date, and older Tertiary strata, do 

 not appear to have been yet recognized in Northern China. 



Of relatively recent geological date are the remarkable widespread 

 deposits of Loess, which sometimes attains a thickness of over a 

 thousand feet. Perhaps no more striking phenomena than these 

 wonderful deposits occur in the whole range of stratigraphical 

 geology, whether we take into account the character of the deposits 

 or the manner of their production. The author has lately given in 

 this Magazine such a lucid and graphic description of the characters 

 and origin of the Loess, that it is not necessary here to refer to the 

 facts brought forward respecting it in this volume. 



Tlie author's conclusions that it is to be regarded as the product 

 of ^olian influences acting during periods of long duration and 

 under different conditions of climate, appear to be fully justified 

 by the mode of its occurrence not only in China but in Europe as 

 well. In Northern China, three of these climatic periods are dis- 

 tinguished : — (1.) An erosion period, in which the surface of the 

 country was sculptured by erosion and denudation into the figure it 

 still retains beneath the covering of Loess. (2.) A Steppe period, in 

 which the conditions of the saline steppes of Central Asia were 

 extended over the area of Northern China. (3.) A Loess period, 

 now existing, in which, through a moist climate, the former Steppe- 

 districts have been converted into Loess districts. 



The author devotes a chapter to considering the effects of marine 

 action on a coast-line in forming planes of denudation, and ai'rives 

 at similar conclusions to those enunciated long ago by Professor 

 Eamsay. 



In concluding this short notice we can but express the opinion, 

 which we feel must be shared by all who consult this grand work, 

 that this book is a most valuable and important contribution to 

 geological science. It presents us with the main outlines of the 

 geological characters of a vast area of country of which nothing had 

 been previously known, so that we are enabled now for the first 

 time to correlate the succession of the strata in China with that of 

 other countries. The difficulties attending an investigation of this 

 character are readily apparent, for not only were the geological 

 features quite unknown, but even the topography of the country was 

 to a large extent a blank, and beyond the position of a few of the 

 large cities and the course of some of the larger streams, the land 

 was a terra incognita. Under these circumstances we can appreciate 

 the arduous nature of the undertaking and the qualifications neces- 

 sary for fulfilling it, and we warmly congratulate Baron Kichthofen 

 on having accomplished it so successfully. We are ver}' glad to 

 know that in a short time the descriptions of the fossils, which have 

 been entrusted to several eminent palaeontologists, will be published 

 in another volume, and we anticipate that the fossil flora and fauna 

 of this area will prove not less interesting and valuable to science 

 than its stratigraphical features. G. J. H. 



