Publication Date:
2017-02-27
Description:
International Ocean Discovery Program (IODP) Expedition 357
successfully cored an east–west transect across the southern wall of
Atlantis Massif on the western flank of the Mid-Atlantic Ridge
(MAR) to study the links between serpentinization processes and
microbial activity in the shallow subsurface of highly altered ultra-
mafic and mafic sequences that have been uplifted to the seafloor
along a major detachment fault zone. The primary goals of this ex-
pedition were to (1) examine the role of serpentinization in driving
hydrothermal systems, sustaining microbial communities, and se-
questering carbon; (2) characterize the tectonomagmatic processes
that lead to lithospheric heterogeneities and detachment faulting;
and (3) assess how abiotic and biotic processes change with varia-
tions in rock type and progressive exposure on the seafloor. To ac-
complish these objectives, we developed a coring and sampling
strategy centered on the use of seabed drills—the first time that
such systems have been used in the scientific ocean drilling pro-
grams. This technology was chosen in the hope of achieving high
recovery of the carbonate cap sequences and intact contact and de-
formation relationships. The expedition plans also included several
engineering developments to assess geochemical parameters during
drilling; sample bottom water before, during, and after drilling; sup-
ply synthetic tracers during drilling for contamination assessment;
acquire in situ electrical resistivity and magnetic susceptibility mea-
surements for assessing fractures, fluid flow, and extent of ser-
pentinization; and seal boreholes to provide opportunities for
future experiments. (...)
Type:
Article
,
NonPeerReviewed
Format:
text