At the ocean floor and below consists of several layers including
nanomarls (1), clays (2), multicolored silty clay (3), that level located 5,000 meters deep, below are black shales (4a and 4b) and nano-limestones (5a and 5b). Below is the oceanic crust composing basalt (7) just below around 5,800 metres deep. The top part were formed during the
Pleistocene and
Miocene age, the second unit were formed during the
Late Eocene age, the b subunit were also formed during the
Late Paleocene age. The lower units were formed during the
Valangian,
Oxfordian and
Kimmeridgian ages. ==Fossil content==