The red notebook of Charles Darwin / edited, with an introduction and notes by Sandra Herbert.

  • Charles Darwin
Date:
1980
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: The red notebook of Charles Darwin / edited, with an introduction and notes by Sandra Herbert. Source: Wellcome Collection.

    89/184 (page 75)
    THE RED NOTEBOOK 75 p. 156.^^® Mines of Batopilas in New Biscay, Nature exhibits the same minerals there, that are found in the veins of Kongsberg in Norway. — namely dendritic silver intersecting carbonate of lime —native silver in Mexico | 169e is always accompanied by Sulp, silver sometimes by selenite. — in New Spain, contrary to Europe argentiferous lead not abundant. considerable quantity of silver procured from martial pyrites; great blocks of pure silver not common in (S.y America: In all climates distribution of silver ¿in veinsj very unequal, sometimes disseminated sometimes concentrated : wonderful quantity of pure silver in S. America.| 170e Geology of Guanuaxuato. — Clay slate, passing into talcose & chloritic slate, with beds of syenite & serpentine dipping to SW at 45° to 50° — covered by conformable greenstone porphyrys & phonolites do. amphibole quartz & mica very rare. —ancient freestone & breccia is the same with that on surface of plains of Amazon, no relation — there is more modern breccia, chiefly owing to destruction of porphyries, whereas other to ancient rock. — this N° 2. superimposed on № 1. even No. 2. might be mistaken for Porphyry I 17le above ancient freestone, limestone & (many) /fother secondaryj rocks.21^ Vein traverses both Clay slate. Porphyry North 52 W, & is nearly the same with that of the veta grande of Zacatecas, & veins of Tasco & Moran — of Guanaxuato to SW. with respect to latter doubts whether bed or vein (very like that of Spital of Schemnitz in Hungary. ) Humboldt says fragments from roof & penetrating over¬ lying beds tells the secret.—^i? p jgp. The small ravins into which the valley of Marfil is divided, appear to have a decided influence on the richness of the veta madre of [continued on page 175] I 170e [misnumbered page]