and other Problems in Pyrenean Geology. 371 



too soft to have stood the journey without a trace of fatigue, and 

 yet it is practically unaffected by the Tertiaiy movements. Why, 

 therefore, suppose the equally undisturbed Cretaceous rocks which 

 rest on it to have been overthrust ? And if the latter be admitted to 

 be in place, the whole case for the overthrust of the Cretaceous sheet 

 at Gavarnie fails.] 



Carez further remarks that at the entrance of the cirque of 

 Gavarnie the bedding of the Campanian is not parallel to the surface 

 of the underlying ' Primary ' rocks. [This is true of the upper part at 

 the place indicated by Carez, where the Campanian sheet thickens 

 beneath the margin of the overlying Palseozoics, but not of the base, 

 the part which counts ; the latter remains parallel to the underlying 

 platform.] 



7. Carez considers that the Tertiary upheaval has been the only 

 movement of importance evidenced in the Pyrenees, to the exclusion 

 even of Hercynian and older crust-creeps. If this were true the 

 junction of the undistorted Cretaceous in the Gavarnie district, etc., 

 with the contorted rocks of the basement-platform would obviously be 

 a fault, but as he admits that his views are not shared by the majority 

 of geologists he does not press the point. \_En passant it is interesting 

 to note that the structures of the i-ocks in the basement-platform are, 

 by different observers, regarded as Archaean, Hercynian, or Tertiary !] 



8. Carez points out that at certain places [along the southern 

 margin of the overthrust Palaeozoic mass] the Cretaceous abuts against 

 that mass, though generally passing below it. He explains this fact 

 by unequal advancement of the Cretaceous from the south against 

 resistance. [It is more simply explained by unequal advancement 

 of the Palaeozoic mass from the north against resistance, a movement 

 which is admitted by Carez and is independent of his overthrust. 

 In fact, the abutting merely proves relative movement between the 

 juxtaposed Palaeozoic and Cretaceous rocks, and has no bearing on the 

 relations of the latter to the underlying platform. Also it appears 

 from his statement that he supposes the Cretaceous to have forced its 

 way heneath the Palaeozoic mass, and that in the form of an apparently 

 undisturbed sheet, several miles wide at least, but only a few yards 

 thick.] 



9. Carez says, "Although the contact of the Upper Cretaceous 

 with its ' substratum ' is remarkably plane, the former is itself strongly 

 folded." Proceeding to his application of the argument in the Gavarnie 

 district we read, "At Gavarnie the Cretaceous beds are intensely 

 folded, and their structure contrasts singularly with that of the same 

 horizons on the' Spanish side, notably in the valley of Arasas. These 

 are indeed the characters of an overthrust mass of which the front 

 is folded several times on itself, although, at a certain distance 

 behind, the beds have preserved a relative regularity." [Passing 

 over the discrepancj^ between this argument and No, 6, we would 

 point out that although the Cretaceous sheet is folded in places, yet 

 its ' substratum ' of crystalline rocks has been folded with it. The 

 folding, in fact, proves not that there has been relative movement 

 between the Cretaceous and its 'substratum,' but merely that they 

 (i.e. really the ' substratum ') have not been absolutely rigid under 



