18 GEOLOGICAL MEMOIRS. 



Leutsch Valley ; it appears again in the west near Widum, along the 

 south slope of the Guhren Mountain to the Ross-Alpe, and further 

 in the Gais Valley, and on the east and south slopes of the Hoch- 

 mundi Mountain. The main mass of the dolomite contains distinct 

 remains of the Megalodus scutatus, proving this rock — and, with 

 it, the Ichthyolite- schists of Seefeld — to he of Lower Liassic age. It 

 is worth remarking that along the whole tract between Zirl and 

 Telfs, the Dachstein- dolomite appears on the inner margin of the 

 calcareous chain, while the older trias appears only further north- 

 ward. The light-coloured triassic limestones continue from Schar- 

 nitz to the Bavarian frontier. 



Well-developed neojurassic and neocomian strata occur in the 

 Koiten Valley, north of Leutsch, as in the ravines north-east of Inns- 

 pruck, where they are associated with Koessen-strata. 



The Waldrast Mountains, and the Saile Mountain (south-west of 

 Innspruck) consist of light-coloured, frequently crystalline limestones 

 and dolomites, overlying dark slaty limestones and slates, which rest 

 on mica-schist. The light-coloured limestones contain Chemnitzice, 

 like those of the upper triassic limestone north of Innspruck. 



[Count M.] 



On the Geology of the North-Western Tyrol. 

 By Fr. Ritter von Hatjer. 



[Proceed. Imp. Geol. Inst. Vienna, August 1857.] 



M. von Hauer, assisted by two Bavarian mining-officers, M. 

 Gumbel and Baron Andrian, has examined the district including 

 the Leutsch- Gurgel-, and Lech-valleys (North-west Tyrol). The 

 prevailing rock is dolomite, with distinct remains of Megalodus 

 scutatus near Telfs. A tract of light-coloured upper triassic limestone 

 extends westward from the Hochmundi mountain, gradually narrow- 

 ing until it totally disappears south of Boden : it is connected on 

 the north with the same formation in the Bavarian Alps (Wetterstein 

 and Zugspitz). Along the southern slope a narrow strip of Car- 

 dita-beds runs between the dolomite and the light-coloured triassic 

 (Hallstadt) limestone. Along the north slope this line is generally 

 overlaid by spotted marls of a later age. North of the Hinterwend 

 mountain, dark-coloured Bacillar-slates, without organic remains, are 

 interposed between the Hallstadt and Gutterstein limestones. 



Deposits of later date — namely Koessen, Adneth, Jurassic, and 

 neocomian strata, spotted marls, &c, generally in narrow zones — lie 

 in irregular superposition over those of an earlier date ; conglo- 

 merates, alternating with yellowish marls, and occurring on the Mut- 

 terkopf mountain (8755 feet), may probably rank among the Gosau 

 series. The zone of Gutterstein limestones includes, near Reutte, 

 organic remains characteristic of the true Muschelkalk, and are the 

 same (Terebratula trigonella, Spiriferfragilis, Sp. Mentzellii, &c.) 

 as have recently been discovered in nearly the same locality by M. 

 Escher von der Linth. [Count M.] 



