Revieics — A. Stiibel — Diversity in Enqjtive Mountains. 521 



wholly of Highland schists, and of large tracts of granite, including 

 the great central mass of Balmoral Forest with Lochnagar, 3,552 feet. 

 Smaller portions of ground are formed of diorite, lamprophyre, 

 serpentine, etc. 



Scattered irregularly about the area are glacial deposits of Boulder- 

 clay, sand, and gravel; also much peat, which is " wasting away in 

 many places, owing to the effects of the east winds in spring". 

 Terraces of valley gravel border the Dee, which traverses the district by 

 Ballater, Balmoral Castle, and Braemar<v 



The memoir, is accompanied by some excellent views of rock 

 structures, but neither map nor memoir contain any sections to 

 illustrate the structure of the country. Even a section showing the 

 profile of the ground, with the outcrops coloured near the surface, in 

 the manner adopted by Jukes, would have been useful and instructive. 

 To complete a section to sea-level would no doubt have been impossible 

 even in diagrammatic form. Moreover, as the Director points out in 

 his preface, the metamorphic rocks are so intensely folded and invaded 

 by igneous intrusions of different ages, thats the authors of the 

 memoir, and their colleagues in adjacent areas, differ greatly with 

 regard to the succession of the sedimentary schists (qnartzites, lime- 

 stones, etc.), and witli regard to the origin and history of the stages 

 of metamorphisni. To the petrographical features of the area the 

 main portion of the memoir is naturally given, and it includes an 

 account of the cairngorms for which the northern granite masses are 

 noted. The local search for stones, however, " has been discontinued 

 for many years, the importation of cheap foreign stones from Germany 

 and Brazil having practically killed the demand." It is noted that 

 the limestones are rich in minerals, developed by thermal 

 -metamorphism, and well known to collectors. "Very fine examples of 

 glacial action are' exhibited by the ice-scratched rocks, the moraines, 

 and the other glacial gravels in the Dee Yalley and its branches. 



III. — Sue ia Diveesite GE]srE:iiQ"crE des Montagnes Eeuptions. By 



A. Stcbkl. 



Translated from the German by W. Pkinz and C. Van de Wiele. 

 Bruxelles, Acad. Eoy de Belgique, 1911. ■ 4to ; pp. 70, with plate and 

 figures. 



,4 IS" introductory note explains 'that arrangements were made by 

 -LJL the Academies Boyales de Belgiques in 1903 for the publication 

 in French of this paper by the late Alphonse Stiibel. The matter 

 was delayed, however, and meafiwhile Professor Prinz, who had 

 undertaken the translation, died, leaving his manuscript incomplete. 

 Under these circumstances Dr. Yan de "Wiele has carried the work 

 through. 



The paper begins by pointing out that the great majority of 

 volcanoes are extinct. From this the conclusion is drawn that 

 volcanoes are supplied from strictly local magma-basins, and not 

 from a unique central reservoir. 



The next point submitted is that all volcanoes, whether active or 

 extinct, are of comparatively recent, that is, of post-Cretaceous date. 

 As this statement is likely to cause the reader unnecessary trouble it 



