320 Notices of Memoirs — F. J. Noth — Mineral Oil in Galicia. 



Beryl occurs in fine crystals, in some cases measuring 10 c. m. in 

 diameter and 30 c. m. in length ; whilst apatite is found in similar, 

 though much smaller, green crystals. Stelzner has discovered 

 triplite — a phosj^hate of iron and manganese — in two varieties, the 

 one light and the other dark coloured ; the former represents the 

 purer and fresher condition of the mineral. Analyses of both 

 varieties are jDublished by Siewert. The alteration of triplite has 

 given rise to heterosite. Near San Eoque Stelzner has discovered 

 the rare mineral Columbite, specimens of which have also been 

 analysed. Some interesting questions are suggested by the para- 

 genesis of the minerals in these quartz-stocks, and their relation to 

 similar occurrences elsewhere. 



Alternating with the old crystalline schists of the Sierra are cer- 

 tain zones of crystalline limestone, which have been specially studied 

 by Stelzner. As accessory minerals in these limestones, he mentions 

 quartz, orthoclase, hornblende, magnesia- mica, titanite, garnet, 

 pistacite, coccolite, scapolite, wollastonite, chondrodite, serpentine, 

 ceylanite, calcite, and malachite. The description of these minerals is 

 followed by an interesting discussion of their probable origin, with 

 special reference to the development of mineral silicates in metamor- 

 phic limestones. 



The third part of Stelzner's paper describes the enargite lodes of 

 the Famatina Mountains. A mineral associated with the enargite 

 is described as a new species under the name of Famatinite. From 

 Siewert's analysis it appears to be a combination of the sulphides of 

 copper, antimony, and arsenic ; in fact, an antimonial enargite, in 

 which part of the antimony is replaced by arsenic. Its composition 

 may be represented by the following formula : 4(3Cu2S. SbjSg) ■\- 

 (SCu^S. As^S^).^ 



After describing the occurrence of a number of other minerals, 

 more or less rare, Dr. Stelzner calls attention to certain sandstones 

 exhibiting curious pseudomorphs after rock-salt. Some blocks of 

 this stone have the surface studded with small hemispherical pro- 

 tuberances, believed to be pseudomorjDhs after a peculiar form of 

 saline efflorescence. The layer of sandstone immediately above 

 this surface would necessarilj'^ show pits corresponding with these 

 elevations, and resembling those little hollows which in many sand- 

 stones represent rain-drops. Without denying that such impressions 

 Tfifxy be preserved under peculiarly favourable conditions, Stelzner 

 raises the question whether some of the so-called " fossil rain-drops " 

 may not be merely the concavities corresponding with pseudomorphs 

 after an efflorescence of salt. F. W. K. 



2. — Ueber die Bebeutung von Tieebohrungen in der Bergol- 

 zoNE Galiziens. By Fr. Julius Noth. Jahrbuch der Tc. Jc. 

 Geologischen Beichsanstalt, Jahrgang 1873, Band xxiii. No. 1, 

 pp. 1-8, with 2 plates of sections. 



THE district in Galicia over which signs of mineral oil occur is 

 said to be sixty miles (German) long, by an average of two 

 to three wide, occupying a great part of the northern branch of the 

 Carpathian Mountains. 



