Ramond has likewise met with this breccia in the Pyrenees.[1] He describes it by the name of “ bandes ” formed of a heterogeneous mixture in irregular veins, occurring between the fundamental granite, and the secondary and tertiary mountains. Other travellers have observed it in similar geological situations, in the Palatinate, Saxony, Bohemia, and particularly in Siberia, where it is stratified, and where jasper constitutes one of the principal elements of it.[2]
An indefatigable artist, the beauty of whose descriptions is not inferior to the graphic charms of his pencil, has proved, that a traveller, without being a profound mineralogist, may, if guided by a spirit of observation, collect materials very useful to those who know how to employ them. Vivant Denon, in noticing the mountains on the road from Keneh to Cosseir on the red sea, says, “ at day-break we found the appearance of the country changed; the mountains that we had passed the day before were rocks of free stone; these were of pudding stone, being a mixture of granite, porphyry, serpentine, and other primitive species, aggregated in green schistus. The vallies continued to grow narrower, and the rocks on every side more lofty. At noon we had reached the first half of our joumey, in the midst of line rocks of breccia, which would be very easy to work if it were not for the great distance from any supplies of provisions: the portions of this granite, of which this breccia is composed, shew, that the primitive mountains are not far distant.”[3]
With regard to the elevation, and abutting of the secondary and tertiary strata as they approach the primitive rocks, Saussure and
