728 LLL VJ OOLKINATES OL MELD OID OGNE 
series three only—the Rauhwacke with the associated gypsum ; 
the R6tidolomite and the Berrias beds, z. ¢., two near the bottom 
and one at the top of the strata—are also found in the normal 
Helvetian series. In the strata between these we find in Switzer- 
land in the Trias, which is in general but weakly developed, 
nothing at all to correspond to the characteristic Muschelkalk, 
Haupt dolomite, Contorta beds (Rhatic) etc. In the Jurassic of 
Switzerland we find a series of clay shales, sandstones, iron 
oolites and gray crinoidal limestones with fossils of middle 
European type and differing throughout from those found in the 
cliffs. These are followed by thick series of dark colored limestone 
with Jura facies in general. 
Geologic relations of cliffs to their surroundings.—The differences 
which we thus see in the facial development of the Swiss strata 
d 
and of the cliff or ‘‘exotic” strata of the same age lying side by 
side with them in north Switzerland, and beside which the cor- 
respondences seem quite insignificant, are so striking as to stim- 
ulate inquiry as to their cause and possible explanation. 
The attempt was therefore first made to determine the rela- 
tions which the cliff masses sustained to the surrounding Helve- 
tian chains, to determine if possible whether these masses 
extended down through the Flysch above which they rose or 
simply lay as rootless block masses wpon the Helvetian chains. 
It will naturally be impossible for us to enter here with any detail 
into a line of evidence based to a great extent upon local struc- 
tural relations of the region studied and involving a considerable 
mass of local description and local facts.‘ There are, however, 
certain general features common to and characteristic of the 
cliffs to which I may refer. One line of such evidence is fur- 
nished by the conditions of the strata in the cliffs as contrasted 
with those near them. A second by the more general relations 
of the cliffs to the surrounding chains. 
If the cliff masses be superficial in their nature, they must 
have been thrust from the side, and we should in that case 
find evidence of such overthrust in the cliff masses them- 
*For these details cf. Beitrage z. geol. Karte d. Schweiz, Vol. XXXIII, Bern, 
1893. 
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