328 ROLLIN T. CHAMBERLIN 



absence of incontestable Devonian deposits, determine in a precise 

 manner the age of the folding in Scandinavia, we can place it, from 

 the analogy with Scotland, at the junction of the Silurian and 

 Devonian/ 



Holtedahl has noted a northward continuation of the Cale- 

 donian mountain-folding in Spitzbergen, but as he found beds 

 which he beheves to belong to the uppermost Silurian resting 

 unconformably upon the Silurian strata which are incorporated 

 in the folds, he would place the date of the folding late in the 

 Silurian instead of at its close, which, if correct, would seem to 

 indicate that the disturbance commenced in the northern portion 

 of the Caledonian chain somewhat earher than it did farther 

 south.^ 



While there was intense crumpling in the Grampian geosyncline 

 and in Scandinavia along this northeast-southwest Caledonian 

 axis at the beginning of the Devonian, folding also took place, in 

 central Europe, at approximately the same time, along a northwest- 

 southeast axis. The folded belt extends from the Ardennes of 

 France through the Taunus and Thiiringerwald into Moravia, 

 where this system of folds disappears under the great overthrusts 

 of the Carpathians, which are of much more recent origin. ^ Farther 

 west than the Ardennes, in the Cotentin region of northwestern 

 France, Lecornu has described Siluride folding which may be a west- 

 ward continuation of this mountain system of central Europe. "* 



In the Sahara Desert recent explorations by Gautier have 

 shown the existence of folding during the Caledonian epoch. The 

 early Devonian strata in the Oran Sahara rest in horizontal or 

 slightly undulating beds upon folded Silurian strata. ^ 



According to Hauthal, South America also suffered from 

 deformative movements at this time.- In the Sierra de la Ventana, 

 of Argentina, Hauthal found that the older Paleozoic sedimentaries 



' Emile Haug, Traite de geologic, II (191 1), 730. 

 ^ Olaf Holtedahl, personal communication. 



3 Emile Haug, op. cit., p. 732. 



4 L. Lecornu, cited by Suess, op. cii., IV, 48. 



5 R. Chudeau and E. F. Gautier, "Sur le structure geologique du Sahara central," 

 Comptes rendus, CLXI (1905), 374-76. 



