Table T4. General review of the most important petrographic features of the different units of Site 1223.
Lithologic
unit
Unit name
Thin section type
Thin sections examined
Average dimension
of the clasts
(mm)
Main constituents
1 Yellowish brown clay and volcaniclastic turbidites Volcaniclastic sand 4 0.1-0.2 Unaltered glass shards, olivine, vitric fragments, plagioclase, lithic fragments, palagonitized glass, clinopyroxene, and radiolarians
2 Volcaniclastic turbidite Volcaniclastic sand 3 0.1 to 1.8 Claystone and carbonate (micrite) clasts plus volcanic sand (plagioclase, clinopyroxene, olivine, opaques, and glass)
3 Dark-brown clay Volcaniclastic sand 1 0.3-1.5 Claystone fragments plus volcanic sand (plagioclase, clinopyroxene, olivine, opaques, and glass)
4 Unconsolidated black sand Volcaniclastic sand 1 0.1-0.3 Unaltered glass shards, olivine, vitric fragments, plagioclase, lithic fragments, palagonitized glass, and clinopyroxene
5 Crystal vitric tuff Tuff 4 0.1-1.1 Olivine and plagioclase clasts plus lithic and vitric fragments and glass shards; chlorite, palagonite, and zeolite
6 Bioturbated claystone Claystone 1

7 Volcaniclastic sandy siltstone Clay with volcanic ash layers 1 <0.2 Olivine and plagioclase clasts plus lithic and vitric fragments and glass shards; chlorite, zeolite, clay clasts, and palagonite
8 Volcaniclastic silty claystone with carbonate-filled cavities Volcaniclastic silty claystone with carbonate granules 1 2.5* Carbonate, glass shards, olivine, vitric fragments, plagioclase, lithic fragments, palagonitized glass, clinopyroxene, and radiolarians
10 Volcaniclastic silty claystone Volcaniclastic sandy claystone 2 0.1-0.2 Olivine and plagioclase clasts plus lithic and vitric fragments and glass shards; chlorite, zeolite, and palagonite
11 Altered palagonitized crystal vitric tuff Altered crystal vitric tuff 4 0.2-1 Olivine, plagioclase and clinopyroxene clasts, plus lithic and vitric fragments; palagonite, serpentine, and zeolites
12 Volcaniclastic silty claystone with white vugs Claystone with paragonite granules(?) 2 0.2-0.7 Anhydrite-filled vugs (maximum size 3.5 mm) and zeolites
13 Volcaniclastic silty claystone Volcaniclastic silty claystone 1 0.06-0.4† Olivine, vitric and lithic fragments, and zeolite
14 Volcaniclastic clayey siltstone Volcaniclastic clayey siltstone 1 0.06-0.4† Olivine, vitric and lithic fragments, zeolite, and chlorite

Note: * = carbonate granules; † = silty fraction.