540 P. W. Stuart-Menteath—TJie Age of Pyrenean Granite. 



Besides the known and admitted Flyscli of the Pyrenean outskirts, 

 'tliere is an interior Flysch which I have been gradually substituting 

 for the Cambrian, Silurian, etc., of official maps. It faces that 

 of Iholdy, as its corresponding southern outcrop, and presents 3,000 

 feet of angular blocks of every age, including fossiliferous Cenomanien ; 

 and it rests on a sheet of that Cenomanien, whose protruding points 

 and edges have been affording me characteristic fossils for over 

 twenty years. This conglomerate consists in great part of ophite 

 blocks, and is crossed and penetrated by vast ophitic intrusions. 

 Between Esterencuby and Eaux-Chaudes it is abundantly visible, 

 and it is now admitted that the limestone on which it rests is not 

 Cambrian but Upper Cretaceous, as I first mapped it in 1885. 



Such radical admissions, along fifty miles and more, have led 

 to the recognition that the central granite of the Pyrenees is post- 

 Carboniferous and intrusive in synclines of Carboniferous rocks. 

 The first of these synclines was proved by me with ample fossils 

 in 1881. Its most certain features are figured in the map of Carez 

 and Vasseur. The Survey geologists next repi'esented my Carbon- 

 iferous of Biriatou as pre-Cambrian, and my Trias of Vera as 

 Carboniferous above Cambrian. In a map published in Gomptes 

 Rendus of June, 1894, I have shown the true relations. Their 

 Carboniferous contains good specimens of BadioUtes foliaceiis, and 

 their pre-Cambrian is the most typical Carboniferous in the Pyrenees. 

 Similarly the Lourdes slates were classed as Silurian, because 

 penetrated by granite, in spite of hundreds of Cretaceous Ammonites. 

 The Cenomanien limestone of Vera, together with the Trias on 

 which it rests, traverses the entire granite, as crystalline and 

 graphitic marble, and emerges with Radiolites and Cretaceous corals 

 towards San Sebastian. It is precisely analogous to the similar 

 marble of the Cambo granite, which similarly emei'ges as Cenomanien. 

 The presence of Muschelkalk, in which I have found the first Triassic 

 fossils of the Pyrenees, is the only source of confusion to be 

 avoided. But since 1885 sufficient fossils have enabled me to 

 certify the presence of Cretaceous at Vera, Argeles, and elsewhere, 

 along the synclines admittedly penetrated by granite. It must be 

 consequently soon admitted that the granite is as little Carboniferous 

 as Archaean. Another twenty years of useless controversy might 

 be saved by impartial evidence on the spot. All the leading authors 

 of the charriage theory have jointly exhibited their ingenuity at 

 Biarritz in applying the resources of that theory to controvert the 

 facts. They start from the sections of M. Carez in Bull. Soc. Geol. 

 of 1896, and terminate with the final refutation of their illusions in 

 the last published Bidletin. The relation of their methods to field- 

 observation can be thus practically gauged, and it may be remarked 

 that the clever educational manual of Commandant Barre quotes their 

 Biarritz speculations as the most certain facts of Pyrenean geology. 



St. Jean de Ltjz, November 5, 1903. 



P.S. — Three recent visits to the " fundamental section " of the 

 new and brilliant paradox of Gavarnie have convinced me that it 

 consists of a bed of Devonian limestone with black schist both above 



