To begin with, here is a little update on our activities: the core complex, a tectonically exposed structure consisting of mantle rocks, is now at the center of our studies. The latest Nautile dives were designed to study the tectonic structures that characterize the core complex. These are extensive and profound extensional faults that our fellow scientists have been able to navigate up and down and within with the Nautile!
The Romanche never ceases to surprise us!
The 15 dives carried out so far have allowed us to collect nearly 250 rock samples between peridotites, basalts and gabbros, more or less fresh and deformed.
Each dive, however, always brings up a sample that, due to its beauty, particularity or uniqueness, tends to stand out more than the others.
This short blogpost is dedicated therefore to Romanche’s “exotic rocks”, to share with you some of the wonders that the ocean floor world can offer:
(A) Peridotite covered on one side by a fibrous serpentine (chrysotile); associated with faults, the fibers grow in fractures during their opening.
(B) Stone completely composed of green fibrous actinolite-tremolite.
(C) Massive serpentine rock with white layer of clay minerals.
(D) Strongly serpentinized rock (blue/black) with clay minerals (white) such as chlorite and talc.
(E) Strongly altered peridotite crossed by serpentine veins (dark green) and big fractures filled by clay minerals (gray/white) such as chlorite and talc.
(F) Possible silica listvenite, result of alteration processes at low temperature; the rock is crossed by “tiger eye” banded veins made of fibrous quartz.
(G) Lobate basaltic crust with beautiful glass drips and turtle-shell texture on the upper portion; this crust was a portion of the magma conduit subsequently emptied and forming drips of magma on the internal part.
(H) Tubolar pillow basalt with 3cm of fresh glass.
(I) Dunite with patches of gabbroic material.