Reviews — Central Scotch Coalfield. 475 



The number of victims is estimated at 25,000, at Avezzano 10,700 

 being killed out of a total population of only 13,000. 



W. H. "WlLCOCKSON. 



VI. — La Ligne de Depression's Pegna-Verin et ses Sources 

 Carbonatees. By P. Choefat. Extrait du tome xii des Coni- 

 municacoes do Servico Geologico de Portugal. Lisbon, 1917. 

 TPHE Gallaico-Durian massif of the North of Portugal is traversed 

 J. by a curious line of depressions, with which are associated 

 a considerable number of mineral springs particularly rich in 

 carbonates. The country rock consists of Pre-Cambrian schists and 

 Cambrian sediments, both being penetrated by granites, supposed to 

 be of Hercynian age. Although the evidence is not very clear, the 

 springs probably have some genetic connexion with the fractures 

 that determine the lines of depression. 



P. H. Pastall. 



VII. — The Economic Geology of the Central Coalfield of 

 Scotland. Area VIII : East Kilbride and the Quarter. 

 Mem. Geol. Surv. Scotland, pp. iv+52, 1 fig. and 2 plates, 1917. 

 Price 2s. 

 rpHIS is the second memoir of a series of which the first was 

 JL recently noticed in these columns (Geol. Mag., September, 

 1917, pp. 426-7). It follows precisely the same lines as its pre- 

 decessor, and contains an interesting account of the strata of the 

 East Kilbride district, which are mostly of Lower Carboniferous age, 

 resting on the plateau basalts. Only at the extreme east of the area 

 is there a small patch of Upper Carboniferous rocks. The very fine 

 sections in Calderwood Glen are described in detail, and special 

 attention is paid to the discovery first made by Mr. Carruthers that 

 here plants of undoubted Calciferous Sandstone age are associated 

 with Posidonomya Becheri and Aviculopecten papyraceus, thus showing 

 that in Scotland the Pendleside facies occurs very low down in the 

 Lower Carboniferous. At the present time the economic productions 

 of this area are of small value, and the interest is mainly strati- 

 graphical and palaeontological. 



P. H. P. 



VIII. — Molybdenum in Natal. 



IN the South African Journal of Science for November, 1916, 

 Mr. A. L. du Toit describes a curious occurrence of molybdenum 

 ores in a sandstone belonging to the upper part of the Karroo system 

 (Molteno Series). The molybdenum minerals occur as an impregna- 

 tion in quite a limited area, in association with iron pyrites and 

 marcasite and some carbonaceous material. The minerals that have 

 been identified are molybdenite, molybdic ochre, and ilsemannite, 

 the two latter being apparently oxidation products of the sulphide. 

 The origin of the deposit is not clear : it does not seem to be detrital, 

 as the patch is well defined from the rest of the rocks ; there are no 

 dykes or any indication of channels by which solutions could have 



