Quart. Journ. Geol. Soc. Tol. LV, PI. XXVII 



SECTION OF THE MOUNTAIN-FOLDS IN THE DAVOS DISTRICT. 



[Scales, vertical and horizontal : Yfjfooo' °^ ^ '""'^ ~ ^'^ miles. Heights ai'e expressed in metres.] 



COTSCHNA-AROSA FOLD STRELA FOLD WIESEN-AMSELFLUH FOLD 



Cotschna ridge Todtalp-Schwarzhorn Schiesshorn-Schia- Amselfluh 



DUCAN FOLD 



horn Hoch Du 



Radiolarian cherts 



Polygenic' brecci. 

 Crystalline 



^ 



ORCY BUNDNEFI SCHIEFER 

 Lias? Tertiary? 



□ 



RED i GREEN ■SCHIEFER' OLDER CRYSTALLINES 



Older Palxozoic? 



CASANNA SCHIEFER 

 Carboniferous ? 



VERRUCANO 

 Permian-Trias 



'ItHTTELBILDUNOEtl' 



AUPTDOLOMir 

 Upper Trias 



LITHODENDRONI 

 Rliaitic 



Through the &st tliree folds ( 

 represents the conditions that exist between the Schiahorn and Kloslers, in an approximately s ' 

 right half of the section would out the fourth Ibid in the hills nboTe Arosa : there the serpentine-band forms no prominent movmtain, such as the 

 somewhat more complex, but the essential structure is probably the same as that shown here in the Cotschna and Parsenn region. 



Todtalp-Schwarzhorn, and the folding may be 



The section is intended to illustrate :— 



(1) The general character and distribution of the mountain-folds in the district; and 



(2) The suggestion that, in the fourth fold, which overlies the great overthrust-plane, there may not be (with the exceptic 



geological elements present which do not occur in the more normal folds to the east, and that the peculiar rocks whi(' 

 explicable as results of the igneous intrusion together with subsequent djnamo-metamorphism. 



Tims (a) the crystalline breccia seems to represent the Casanna Schiefev of other folds, here brecciatcd in situ ; (4) the ' polygenic' breccia is here a result of the crushing- 

 together of Verrucano, Trias, etc. along the ovcrthrust-plane ; (c) the radiolariiin cherts and shales occur between the Verrucano and the Trias, the shales being partly interstratifled 

 with the latter; (d) the 'Bed and Green Schiefer ' result from (he intrusion of tlie peridotite-magma through the red schii 



of the serpentine and associated igneous roots) any 

 I here characterize the neighbourhood of the serpentine are 



J and lower limestones. 



