176 Reviews — Platiniferous Deposits 



a belt of slates, which extends from the Wakham (Nicholas) range 

 to the Taghdumbash Pamir in Chinese Turkestan, and this is followed 

 further north by a calcareous series known as the Pamir Limestone. 

 This is the most prominent rock of the Russian Pamirs, and includes 

 rocks of Triassic and Jurassic age. North of the Pamir Limestone 

 comes a group of slates, probably identical with those of Wakham, 

 but associated with shales and limestone containing Upper Devonian 

 fossils. Beyond this belt, in the valley of the Kizil-su, there is 

 a typical development of the Ferghana series. The strike of all these 

 rocks, both in Chitral and the Pamirs, follows the general direction 

 of the ranges. In Chitral it changes from S.W.-N.E. in Western 

 Chitral to W.-E. in the Yasin district, and no doubt turns down to 

 the south farther east. In the Pamirs the strike in the central 

 parallel ranges is W.-E., and this swings round to the S.W. at 

 the west end and to the S.E. at the east end, following the general 

 lines of the great bay in the Himalayan folds, which contains the 

 North-West Provinces of India. These observations show that the 

 Chitral Mountains and the Pamirs are true tectonic features. 



Up to the present the Pamirs have always been represented on 

 maps as being bounded on the east by two parallel ranges running 

 north and south, which were assumed by Suess and Fiitterer to be 

 true tectonic features, and to indicate a great irregularity in the 

 trend of the chief structural lines of this part of Asia. This, 

 however, is not the case. In both these ranges the strike is fairly 

 constantly W.-E., at right angles to the trend of the range, and only 

 occasionally turns to the N.W.-S.E. The western or Sarikol range 

 may then be regarded as "the eroded scarp of the Pamir plateau", 

 while the eastern or Kashgar range probably owes its origin to the 

 elevation and induration of the strata round the granite masses 

 which form the peaks of Kungur and Mustagh-ata. The strike 

 probably changes round these granites, but not more than is usually 

 the case in the neighbourhood of large intrusions ; so that the range 

 is only partly tectonic, and offers no evidence in favour of the theories 

 of Suess and Fiitterer. 



W. H. W. 



III. PlATINIFEKOTJS DEPOSITS OF SPAIN AND PRUSSIA. ETUDE COMPAREE 



DES GlTES PlATINEFERE DE LA SlERRA DE PiONDA ET BE l'OeRAL. 



Par Louis Duparc et Aegustin Grosset. Mem. Soc. Phys. Hist. 

 Nat. Geneve, vol. xxxviii, pp. 253-290, 1916, avec 7 figures, 

 1 carte, et 4 planches. 



PERIDOTITES and serpentines occur on an extensive scale on the 

 southern slopes of the Sierra de Ponda, between Malaga and 

 Estopona, and M. Orueta, who has recently mapped the district on 

 a scale of 1 : 100,000, impressed by the resemblance of the rocks to 

 those which are now recognized as the source of platinum in the 

 Urals, examined the alluvia of several rivers draining the district 

 and found platinum in them. 1 



1 In a note published in the Comptes Rendus Acad. Sci. Paris, torn. 162, p. 45, 

 1916, M. Orueta states that 50 " sondages " in the alluvial deposits yielded 

 on the average 3 grams per cubic metre, with a maximum of 28 grams. 



