Abstract
IN this volume Dr. E. Trutat gives a sketch, as the full title states, of the mountains, glaciers, mineral springs, atmospheric phenomena, flora, fauna, and man in the Pyrenees, illustrated by woodcuts and diagrams, together with two small maps. The mountains differ from the Alps in their greater simplicity of structure, for they form “the most perfect type of a regular chain.” Like the Alps, this consists of an axis of crystalline rocks, granites, gneisses, and schists, flanked on both sides by deposits comparatively unaltered. But there is one important difference: in the Alps, systems anterior to the Carboniferous are only recognised in the extreme east; in the larger part of the chain, rocks of that or of a later age rest on crystalline schists, which must be very ancient. But in the Pyrenees schists truly crystalline are succeeded by great stratified masses which have been much less markedly changed. The most ancient of these are assigned to the Cambrian, though as yet fossils either have not been found, or are too ill-preserved to afford any certain evidences of age. It seems, however, clear that they are older than the Silurian system, for the different members of this can be identified in several places by their characteristic fossils. The Devonian system is well developed, and followed by limestones (marine), conglomerates, and slaty rocks of the Carboniferous period. The occurrence of Permian rocks is considered by Dr. Trutat to be doubtful. Trias, of the Lorraine type, is found, followed by representatives of the various systems in orderly succession up to the Neocomian. Between this and the Cretaceous is a break, then the sequence continues till after the Nummulitic age. Then, as in the Alps, began the great series of movement, of what the present chain is the outcome. Masses of eruptive rock are connected with these disturbances. The enormous beds of conglomerate, called the Poudingues de Palassou, which sometimes surpass 1000 metres in thickness, recall the Alpine nagelfluhe. Strata partly marine, partly freshwater, represent the Miocene and the Pliocene; the Quaternary deposits presenting a general resemblance to those of the Alps.
Les Pyrénées.
Par Eugène Trutat. (Bibliothèque Scientifique Contemporaine.) (Paris: J. B. Baillière et Fils, 1894.)
Article PDF
Rights and permissions
About this article
Cite this article
B., T. The Pyrenees. Nature 49, 122 (1893). https://doi.org/10.1038/049122a0
Issue Date:
DOI: https://doi.org/10.1038/049122a0