Roche magmatique - microlithique - Basalte

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echantillon
lame
LPA
LPNA
LPNA

Origine : Ascension Island (milieu de l'Atlantique) - lame réalisée par Lithologie Bourgogne - achat sur ebay

Aux dires du vendeur, cette roche correspondrait à une portion récente de plancher océanique.<
Toutefois, si on va sur ce site, à part un volcanisme de point chaud, je ne vois pas.

Description du vendeur d'ebay.

This listing is for a very interesting specimen. It is a piece of crustal rock from the Mid Atlantic Ridge and as such is some of the youngest crustal rock on earth. There are only nine surface localities in the world where you can collect this material because, as the name suggests, the ridge in the centre of the Atlantic Ocean under a couple of miles of water. Ascension Island is only 60 miles from the ridge and was formed by the same plate tectonic forces that still form the ridge today. The rocks on Ascension Island are geologically young (the oldest rocks exposed at the surface are only 1 million years old) and are the same as those found in the ridge itself.