Tertiary Igneous Rocks of the Pyrenees

Abstract

THE review of the treatise of Beyschlag, Vogt, and Krusch in NATURE of August 3, 1916, gives prominence to their mention of supposed absence of Tertiary igneous rocks. Yet even their pages figure grey-copper veins of Los Arcos cutting Tertiary beside ophite and granite intrusions. The latest official map of a Pyrenean district (Orthez) figures the ophite veins cutting uppermost Cretaceous, which I have insisted on during thirty years. In that time I have succeeded in securing by fossil evidence the recognition of the Cambrian of the map of 1890 as Hippurite Cretaceous, the Silurian slates of Lourdes as Middle Cretaceous, and the Scolithia beds of San Sebastian as Nummulitic Eocene. The erroneous classification led to the conception of the entire Pyrenees as rolled from the Sierra Nevada in such confusion and reversal as forbid attention to local and detailed observation, in the progressive correction of the map of Dufrénoy.