Vol. 50.] GOSATT BEDS OF THE GOSATT DISTRICT. 125 



scribed in Transylvania by Maurice de Tribolet. 1 That author 

 describes a collection of fossils from Monorostia, on the Maros, 

 which occur as impressions in a reddish ferruginous sandstone, and 

 from which 24 species of Gosau forms have been determined. Several 

 other localities for various beds of the same age are also known in 

 South-eastern Hungary, in Southern and Western Transylvania, etc. : 2 

 but these, of course, do not come within the province of the Eastern 

 Alps. 



Returning now to the Gosau Valley, we find that it is compara- 

 tively easy to establish the boundary-line between the Gosau Beds 

 and the older Triassic limestones, upon which they rest everywhere 

 with a marked unconformity. I do not know of any spot in the 

 Gosauthal or in the Russbachthal where this unconformable junction 

 is actually exposed to view, but everywhere the stratigraphical 

 evidences of it are too clear for one to mistake their significance. 

 As a rule the older Triassic limestones tower up above the younger 

 Gosau Beds as steep mountain-slopes or almost perpendicular 

 precipices, so that the actual boundary-line between the two is 

 almost always covered over by talus. In the Gosauthal proper 

 we find the younger beds extending from near Gosau Schmidt on 

 the south to the foot of the Barn Bach on the north. On the eastern 

 side of the valley they form the lower slopes of the Ressenberg and 

 part of its summit, while on the western side they constitute the 

 whole range of mountains from the Zwiesel Alp to the lower slopes 

 of the Russberg and the Hohe Platten, the highest in the range 

 being the Hornspitze, about 5000 feet above sea-level. They are 

 continued westward into the Russbachthal as far as Heugut, and 

 stretch up the tributary valley of the Randoa Bach on the north as 

 far as Neue Alp. The total area occupied by the beds would probably 

 not average much less than 30 square miles. 



The Map which is included in this section illustrates the distri- 

 bution of the Gosau Beds in the Gosauthal and the Russbachthal. It 

 is based on the Austrian Ordnance Survey Map (Zone 15, Col. ix. 

 Ischl & Hallstatt — scale 1 : 75,000), on a copy of which I marked 

 in from my own observations the extent of the beds and the nature 

 of the principal strata in the different parts of the district. A 

 geologically- coloured map of this district was published with Reuss's 

 memoir on the Gosau Beds (Denkschrift. Akad. Wien, vol. vii. 1854), 

 but I had not seen this until my own was completed. My own map 

 will be seen to agree with Reuss's in the main, but to differ in several 

 smaller, though not unimportant points, chiefly with respect to the 

 boundary-line between the Gosau series and the older Alpine 

 limestones. (For Map, see p. 126.) 



By far the best series of natural exposures of the beds are found 

 on the sides of the peculiar ravines or gullies (yriiben), in which the 

 mountain-streams are confined, and which are so characteristic of 

 the district. Often, however, as in the lower part of the Wegscheid- 



1 Neues Jahrb. 1875, pp. 52, 53. Noticed in Geol. Record for 1875, p. 104. 



2 Fr. von Hauer, ' Die Geologie der osterr.-uugar. Monarchie,' 1878, 

 pp. 534 and 536-538. 



