Notices and Extracts from the Minutes of the Geological Society. 497 



head, the Lead-hills, and Northumberland ' ; to the mines of Huelgoet and 

 PouUavaen in Brittany 2; to those of Macagnaga and Allay na at the foot of 

 Mount Rosa^, of Sardinia*, Corsica^, and Elba''; to the metalliferous veins of 

 the Vosges^ near Brescia^ in the Alps, and the Altai chain^; — all of which 

 occur in districts where unstratified rocks are known to exist. 



The author, however, states, that besides the evidence thus afforded of the 

 connexion of igneous rocks with metalliferous deposits, it is necessary to have 

 a knowledge of the stratification of the formations in which mines are worked 

 before any legitimate conclusion can be drawn. 



In reply to the third question, — Do metalliferous deposits exist entirely dis- 

 connected from unstratified rocks? — the author enumerates the mines of the 

 Netherlands'*'; those of quicksilver at Idria ; the lead mines of Poggau in the 

 valley of the Mur ; Pezay and Macoz in the Tarentaise ; the copper slate of 

 Mansfeld and Thuringia ; and the veins of galena in the inferior oolite near 

 Prome'^ in the magnesian limestone of Durham 12^ and the mountain-lime- 

 stone of England. 



The author then gives, as a general illustration of his subject, a sketch of 

 the countries between the Alps and the western extremity of England, and 

 shows that igneous rocks and metallic deposits are totally wanting in the whole 

 of the districts extending from the foot of the Alps across the valley of Lac 

 Leman, the Jura chain, the plains of Pranche Comte and Burgundy ; in the 

 oolitic, green-sand, chalk, and tertiary formations of the north-west of France, 

 and in the tertiary and secondary formations of England as far as Devonshire ; 

 but that, on the contrary, when the unstratified rocks recommence in the last- 

 mentioned district, metallic veins reappear. 



' Conybeare and Phillips, Outlines of the Geology of England, pp. 443, 444, 445, and 447. 



* D'Aubuisson, Journal des Mines, tome xxi. p. 81. 



^ Saussure, Voyages dans les Alpes, § 2132 et seq., et § 2151. Von Wellen, Der Monte Rosa, 

 pp. 55, 56, 1824. 



* Marmora, Mem. du Museum, tome xi. 



^ Gueymard, Annales des Mines, lere Serie, tome ix. p. 123. 



'' Pini, Journal de Physique, tome xii. p. 413. Edinburgh Philosophical Journal, vol. ii. p. 177. 



7 Elie de Beaumont, Couj) d'ceil sur les Mines, p. 33, et seq, ; Dictionnaire des Sciences Natu- 

 relies, tome xxxi. p. 388. Art. Mines. 



" Brocchi, Sulle Mi^iera del Dipartimento della Mclla, tomo ii. pp. 248, 273, 2-74, 275. 



"^ Renovaz, Mineralogische Nachrichten von den Altaischen Gehiirgen. Elie de Beaumont, Covji 

 d'ceil sur les Mines, pp. 77, 78 ; Dictionnaire des Sciences Naturelles, tome xxxi. p. 382 et seq,, Art. 

 Mines. Pa.tr'm, Journal de Physique, tome xxxiii, p. 81. 



'** D'Omalius d'Halloy, Memoire Geologique sur la France et quelques Pays voisins, 



" Philosophical Magazine, New Series, vol. ii. p. 234. 



'* Sedgwick, Trans. Geological Society, Second Series, vol. iii. pp. 77, 78, 105, 108. 



