Article Nº 1168 Geology and mineralogy Vol. I · pp. 673–674
Dendrites
Dendrites are dark, moss- or alga-like infiltrations of manganese and iron salts inside laminated rocks; the entry notes where they occur in the archipelago.
Infiltrations, usually of manganese and iron salts, found inside rocks with a laminar fracture; they are dark in colour and look like pressed algae and mosses. They are common in the trachytes of the Serra de Nossa Senhora (‘Our Lady’s upland’), on Porto Santo, and rare in the basalt slabs of São Martinho. S.
Places mentioned