Vol. 50.] GOSAU BEDS OF THE GOSATJ DISTRICT. 149 



valleys of the Alps. 1 But the mode of occurrence of these beds- 

 does not necessarily prove that the present valleys of the Eastern 

 Alps were already marked out in Upper Cretaceous times. What 

 we can say for certain is that they were deposited in trough-shaped 

 depressions in the older Secondary rocks, and we should naturally 

 expect, under these circumstances, that the present lines of drainage 

 would cut through them where opportunity occurs, since they would 

 be of a much more yielding and easily-disintegrated nature than the 

 older rocks on which they rest. 



Sedgwick and Murchison, struck by the isolated position of the 

 Gosau Beds, supposed that several of the now-isolated patches were 

 originally connected, and were deposited in a deep bay within the 

 Alpine chain. 2 Probably many such patches, like those of Zlam. 

 Gosau, Abtenau, and St. Wolfgang, were originally continuous, and 

 were deposited in bays on the southern boundary of the great Upper 

 Cretaceous Sea of Central and Southern Europe. Otherwise it is 

 difficult to account for the succession of strata being almost the same 

 in each case, if we suppose that the now-isolated patches existed as 

 such at the time of deposition. 



From the stratigraphical situation of the Gosau Beds, and the 

 occurrence of the calcareous conglomerate at their base, it is evident 

 that the older Secondary rocks of the Eastern Alps on which they 

 rest had undergone elevation and denudation, with a considerable 

 amount of earth-movement, accompanied by contortion and plication, 

 previous to the period of depression during which these beds were 

 deposited. During their deposition the Eastern Alps probably 

 existed as fairly high land along the central portion of the chain, 

 with a very irregular coast-line along its northern flanks. At the 

 close of Cretaceous times there was probably considerable elevation- 

 followed by depression in the Eocene period at the time of the 

 deposition of the jSTummulitic rocks and the Elysch. Then followed 

 the period of the great Alpine uplift, a movement intense in the 

 western portion and gradually dying out towards the east in the 

 direction of the Vienna Basin, and it is to this period that the 

 present structure of the mountains is chiefly due, as also the present 

 isolated and elevated position of the several small areas covered by 

 the Gosau Beds. 



VI. Summary. 



It now only remains to summarize briefly the description 

 which I have given of the stratigraphy, palaeontology, physical 

 history, etc., of the Gosau Beds of the Gosau district. 



After an account of the previous literature of the subject had 

 been given, and the physical aspects of the Gosau Valley had been 

 described, I pointed out that the Gosau Beds are found in various 

 isolated trough-shaped depressions chiefly on the northern flanks of the 

 Eastern Alps, such as the Gosau Valley, the Zlamthal (near Aussee), 



1 Zittel, Denkschrift. d. kaiserl. Akad. Wissensck. Wien, vol. xxv. (1866) pt. ii„ 

 p. 160. 



2 Trans. Geol. Soc. ser. 2, vol. iii. pt. ii. (1832) p. 367. 



