SEABED SAMPLING

We focused on dredging, with the aim to recover basalts and mantle materials. The location and description of the samples are located in Tab.7.

Fifteen sites were dredged for rock samples from submarine slopes and escarpments in and around the ABFZ (Fig.24. Two dredges were lost during the operations. One dredge sample contained basalts, while all other dredges contained peridotites and/or erratics.

figure

Figure 24: AB06 dredge locations.

The basalts and peridotites will be subjected to intense geochemical (major and trace elements, Nd, Sr, Os and other isotopes, water content, melt inclusions) and geochronological analyses, especially on the glasses of the pillows.

Table 8 gives details on the rock lithology and recovery. In Appendix 7.3 Table 9 presents the rock subsampling and descriptions.

Table 8: AB06 dredge descriptions.

STA-ID	TECTONICS	LOCALIZATION	LITHOLOGY	RECOVERY
S2315	Ridge axis	Near transform fault		lost
S2317	Ridge axis	Western segment; small axial basin	99% pillow basalts with or without fresh glassy crust; 1% gabbros; 1 peridotite sample	100 kg
S2318	Ridge axis	Western segment; Central deep basin	60% peridotite, 40% gabbros, 1 basalt	30 kg
S2319	Ridge axis	Western segment; North steep fault	erratic granitoids	10 kg
S2320	Ridge axis	Eastern segment		empty
S2321	Ridge axis	Eastern segment		empty
S2322	Ridge axis	Eastern segment		empty
S2323	RTI	Nodal basin; west RTI	50% peridotite, 50% erratic granitoids	5 kg
S2324	RTI	Inside corner high; west RTI	100% peridotite	5 kg
S2325	FZ	Western wall FZ	95% peridotite, 5% breccia	100 kg
S2326	FZ	Western wall FZ	80% peridotite, 15% erratic granitoids, 5% basalt
S2327	FZ	Western wall FZ	erratic granitoids	5 kg
S2328	FZ	Western wall FZ		empty
S2329	FZ	Western wall FZ	1 sample of gabbro (erratic?)	2 kg
S2330	FZ	Western wall FZ	erratic granitoids	15 kg
S2331	FZ	Western wall FZ		empty