Publisher's Synopsis
This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1826 Excerpt: ...to light. It remains to indicate suc-cinctly the natiire and relative age of these formations. In order not to confound facts.With geognostic opinions, I shall describe these formations without dividing them, according to the method generally followed, into five groupes of primitive, transition, secondary, tertiary, and volcanic rocks. I was fortunate enough to discover thetypes of each groupe, in a region where, before my voyage, no rock had According to the manuscript notes of M. d'Eschwege, and his Geogn. Gemalde von Brasilien, p. 6. The strata of the primitive and intermediary rocks of Brazil run very regularly, like the Cordillera of Villarica (Serra do Espinhaeo) hor. 1'4 or hor. 2 of the compass of Freiberg. (N. 28 E.) The inclination of the strata is generally towards the E.S.E, been named. The great inconvenience of the antient classifications is that of obliging the geologist to establish fixed demarkations, while he remains in doubt, if not respecting the spot or the immediate superposition, at least on the number of the formations which are not deve-loped. How can we pronounce in many cir-cumstances, on the analogy which a limestone with but few petrifications may present with intermediary limestone, and zechstein, or" a sandstone superposed on a primitive rock, with variegated-sandstone and quadersandstone, or finally, mariatiferous clay, with the red marl of England, and the gem-salt of the tertiary soils of Italy-P When we reflect on the immense progress made within twenty-fivg years, in the knowledge of the superposition of rocks, it will not appear surprizing that my present opinion on the relative age of the formations of Equi-noxical America, is not identically the same with what I advanced in 1800. To boast of-a of opinion in geogno...
