basanites

Updated: May 23, 2025

Amphibole, sometimes pure and forming intermediate strata, at other times mixed with granite, as in the basanites or basalts of the ancients, may, of itself, furnish all the iron contained in the black and stony lavas. This quantity amounts in the basalt of the modern mineralogists only to 0.20, while in amphibole it exceeds 0. 30.

Alexander von Humboldt - Personal Narrative of Travels to the Equinoctial Regions of America, During the Year 1799-1804 — Volume 1