Table T1. Massive and semimassive sulfide sample details.
Core, section,
interval (cm)
depth (mbsf)
12R-1 (Piece 16, 120–122) 142701 107.70 Mineralized volcaniclastic with altered tube pumice and nonvesicular fragments. Slice cut from the semimassive sulfide interval, where wallrock clasts are dispersed and matrix-supported by granular quartz-pyrite vein material with minor replacement veinlets along fractures. Chalcopyrite is concentrated in vague layers, intergrown with pyrite and quartz and locally mantling the former. Traces of anhydrite intergrown with matrix quartz, and rare sphalerite and magnetite inclusions in pyrite.
1R-1 (Piece 1A, 0–4) 142703 31.00 Semimassive sulfide with irregular aggregates or nodules of intergrown pyrite-chalcopyrite set within a bladed to granular anhydrite-gypsum-pyrite-(chalcopyrite) matrix. Local patches of anhydrite-gypsum with scarce sulfides. Euhedral pyrites border many aggregates. Chalcopyrite forms ragged overgrowths on pyrite and also inclusions within pyrite. Rare sphalerite as inclusions in pyrite. Small fragments of altered, vaguely perlitic wallrock with finer grained disseminated pyrite are scattered through the rock.
3R-1 (Piece 4, 34–37) 142705 50.04 Semimassive sulfide composed of granular quartz and pyrite, free of anhydrite, with some euhedral quartz terminations developed in drusy cavities. Sample as provided was evidently broken from a thick vein in altered wallrock. Slice sawn to avoid wallrock fragments along one side.
5R-1 (Piece 2, 12–22) 142706 69.42 Jigsaw-fit breccia with white, altered perlitic wallrock fragments just supported by a matrix (locally veinlike) of coarse-grained, semimassive pyrite and quartz. The pyrite tends to form clusters with euhedral faces at their border. Quartz mostly granular but shows euhedral terminations in drusy cavites, overgrown by rare anhydrite blades. Sample was broken, and matrix fragments hand-picked for Pb isotope analysis.
Sand packed on hammer drill. 142807 <31 Contains particles to 5 mm diameter. Subequal proportions of massive sulfide and pale creamy altered wallrock fragments (with fine-grained disseminated pyrite), and rarer aggregates of bladed white anhydrite (scarce gypsum), some with pyrite inclusions. The massive sulfide particles are compact and predominantly composed of euhedral and subhedral pyrite grains up to 0.2 mm across. Occasional black particles with sphalerite and scarce barite blades. No quartz grains or particles of unaltered dacite. Portion of sample finely ground for analysis.
Lump caught on bowspring of logging tool. 142808 >35 (<100?) Massive pyrite with numerous small cavities lined by euhedral crystals. Neither quartz nor anhydrite is present, but there are a few small fragments of creamy white altered dacite with disseminated pyrite. Resembles many veins from the stockwork zone in Hole 1189B (31 m to ~100 mbsf), lacking in the lower sequence >120 mbsf. Portion of sample sawn off for analysis.

Note: CSIRO = Commonwealth Scientific and Industrial Research Organisation.