522 Beiuews — J. J. Sederhohn — Granite and Gneiss. 



three-angled stones, and other matters of interest. Dr. Barron 

 considers that the direction of the wind, not the prevailing wind, 

 causes the erosion, and agrees with Dr. Vaughan Cornish, but differs 

 from the majority of writers on the subject. He compares this 

 locality with the Libyan Desert, and finds that in both areas the sand- 

 carrying wind comes from the south-west, while the prevailing wind 

 comes from the N.N.AV. And this is shown by the orientation of 

 the sand-dunes, the planed-down surfaces of the rocks, and the 

 direction of the long slope of the dunes. An excellent index has 

 been provided by those who have so carefully seen our lamented 

 friend's manuscript through the press. 



"V. — Granite and Gneiss. 

 Sedekholm (J. J.) : On Gkanite and Gneiss, their Origin, Relations,. 



AND OOCURRKNCE IN THE PrE-CaMBRIAN CoMPLEX OF FeNNO- 



Scandia. Bull. Comm. geol. Finlande, No. 23, Helsingfors, 1907. 



THIS is a long summary in English of a paper in Swedish in which 

 the author shows, through the investigation of the schists of 

 Finland, that rocks occur in these masses showing every sign of 

 having been formed by the same slow processes of sedimentation as 

 younger strata, or by true volcanic action, but differing as to its 

 intensity, or the conditions under which the magma solidified, from 

 that of later times. These pre-Cambrian sediments have been traced 

 throughout the whole eastern portion of Fenno-Scandia, and analogous 

 rocks have been found in the western area of the region. Finnish 

 geologists have also traced these pre-Cambrian beds progressively 

 downwards in a geological sense, and backward in time until they 

 have apparently reached the bed-rocks of this ancient area. Ascertaining 

 the probable origin of any rock-mass in the region, their relative ages 

 have been determined by studying the contact-relations to each other, 

 especially with regard to those granitic masses which have the widest 

 extension. The relations of the different rocks to the great orogenetic 

 movements which have affected the region, and have impressed upon 

 the rocks their widely differing secondary characters, have also been 

 observed. From all this the author has evolved a classification 

 which seems to him to hold good for a great part of Fenno-Scandia. 

 Descriptions and illustrations of all these rocks are given, as well as 

 a geological map of 1 : 8,000,000 showing their distribution. 



VI.- — Geological Literature for 1907. 



ONCE more it is our pleasing duty to call the attention of geologists 

 to the "Geological Literature added to the Geological Society's 

 Library during the year ended December 31st." This remarkable 

 work, compiled entirely by Mr. William Rupert Jones, and edited 

 by Mr. L. L. Belinfante, has now reached its fourteenth year. It 

 consists of 120 pages of author titles, thus listing about 3,000 items, 

 and an index to their contents of 90 pages, which index includes 

 a number of maps not placed among the author titles. It is compiled 

 by one who is thoroughly conversant with his subject in all its varied 



