GEOLOGY OF THE WESTERN ALPS. 153 



while shore deposits were formed upon its flanks. Farther 

 away from the ridge deposits were laid down on either 

 side in much deeper water. To the west occurred the 

 " Lias a facies dauphinois," and to the east the " schistes 

 lustres," which, he says, we now know to be "really 

 Mesozoic". Exactly the same condition of things occurred 

 in the Prealpes, where Lias was being deposited on either 

 side of a land area. In the Middle Jurassic part of the 

 Zone du Brianconnais was still above water. In the 

 Upper Jurassic the Prealpes became wholly submerged. 



With the Cretaceous we get a repetition of similar 

 conditions over the same areas. Thus where in the 

 Jurassics we had massive limestones, these occur again in 

 the Neocomian. Thus Haug contends that the main 

 characteristic of the geology of this area is the repetition 

 of beds of the same lithological character on the same site 

 at different geological periods, as in the Lias, Dogger and 

 Neocomian. 



He says at different times we should have had the 

 same variations along a line across this region at right 

 angles to the zones. Starting from what is now the plain 

 of Northern Switzerland and going southward, we should 

 have found first a shallow-water sea ; this would deepen 

 southward until somewhat "oozy" deposits were laid down. 

 Then on the summit and flanks of the Prealpes we should 

 have found shore deposits being formed, and then a re- 

 petition of the deep-water beds in what is now the Rhone 

 Valley. These again passed into the littoral deposits on 

 the shore of the Limestone Alps. 



Haug therefore concludes that the resemblance between 

 the beds of the Prealpes and those of the Brianconnais is 

 due to the identity of the conditions under which they 

 were formed, and is no proof of an original connection 

 between them, or of the Prealpes being part of an over- 

 thrust from the zone of the Brianconnais. He maintains 

 that the fact of the Upper Cretaceous beds of the former 

 being unrepresented in the latter is a sufficient disproof 

 of Schardt's hypothesis. Moreover, the Eocenes occur 

 upon members of the pre-Liassic series in the Prealpes in 



