Professor Favre on the Geuloyy of the German Tyrol. 81 



perceive that the mountains which flank the valley are com- 

 posed of the formations we liave described ; we then traverse 

 the Klam, formed of saccaroidal limestone, and arrive at 

 the small town of Lend. If we go from that place towards 

 the iron mines of Dienten, we pass over the edge of strata 

 which run southwards, and consequently rest on the central 

 chain. These strata are formed of grey argillo-talcose slates 

 and green slates, aUernating with each other, and identical 

 in appearance with the most abundant beds of the southern 

 Yalais; near Dienten (above and below the village), these 

 formations contain beds of carbonated iron, which dip at 30 

 to the north. These beds, which ai'e mined, closely resem- 

 ble the mines of spathic iron in Dauphiny. They contain 

 crystals of spathic iron, rhombohedric, lenticular, &c., which 

 often rest on crystals of quartz. The important fact is, that, 

 in the interior of these iron mines, a thin bed of graphite is 

 found, very nearly pure, containing fossils referrible to the 

 Silurian epoch. Those in tlie collection of the School of 

 Mines of Vienna bear the following names : — Qardium gra- 

 cile, Munst., Canliola interrupta, Brod., Orthoceras styloideum, 

 Bar., O. gregariiwi, Munst.* 



Although we examined the geological position of these 

 mines, we cannot give any positive opinion respecting their 

 age, the fossils in our possession not being sufficiently nume- 

 rous. Without venturing on any exact determination, we 

 may state that we have been struck with the striking resem- 

 blance which exists between the orthoceratites of Dienten, 

 which are called Silurian, and those of St Cassian, which are 

 evidently from the musclielkalk. It would, indeed, be less 

 extraordinary to find at Dienten fossils of this latter forma- 

 tion than those of the Silurian epoch. 



However this may be, the discovery of these fossils, which 

 was made only a few years ago, promises to be of great im- 

 portance in the geology of the Alps ; for the rocks of Dien- 

 ten are similar to those of the Valais and Dauphiny. 



With regard to the true coal formation, its presence is 



* Morlot. Erldutfrungen. Explanation of the Geological M.ap of the N. E. 

 1-ortion of the Alps, p. 131. 1847. 



VOIi. XLVII. NO. XCIIl. — JULY 1849. P 



