A chimney from the deep sea.
This sample was collected during an oceanographic mission by our colleagues, marine geologists of LNEG, from the Lucky Strike Hydrothermal Field (-1716m deep). It is a fragment of a “black smoker” belonging to the Atlantic Ridge System and where high metallic concentration fluids are expelled at high temperatures.
Along those Ridges, new oceanic crust is formed by the ascending magmas, pulling apart the continents (America and Europe).
The important Alentejo mines (Aljustrel, Neves Corvo) have been formed about 300 million years ago (Upper Devonian – Carboniferous) by similar process.