Table T1. Summary statistics for in-house sediment standards used for the carbon and biogenic silica analysis, including results of second digestion of residue from 1218C composite standard and reagent-grade talc.

Table T1. Summary statistics of in-house sediment standards used for carbon and biogenic silica analyses. First digestions of talc and second digestions of residues (1218C Composite Standard and reagent grade talc) suggest that silica contamination from clay mineral dissolution is low.


Sediment standard	Description		Average (wt%)	Standard deviation (wt%)	N	Notes
			Carbon
Midway in-house	W8709A-5BC:5–20 cm	NE Pacific hemipelagic	2.64	±0.02	523	Total carbon
Midway in-house	W8709A-5BC:5–20 cm	NE Pacific hemipelagic	0.85	±0.01	570	Organic carbon
			SiO₂
1218C composite	Cores 199-1218C-18X and 21X	Radiolarian ooze	32.2	±2	87
1218C composite residue	Cores 199-1218C-18X and 21X	Residue from KOH digestion of radiolarian ooze	1.6	±0.69	9	Second digestion of sediment residue
1219A composite	Cores 199-1219A-19H through 27X	Radiolarian ooze	56.3	±1.7	52
1098B composite	Section 178-1098B-3H-4	Diatom ooze	31.2	±1.4	14	This study
1098B composite	Section 178-1098B-3H-4	Diatom ooze	32	±2	41	Previous work
Reagent-grade talc		Phyllosiclicate	1.5	±0.3	26
Talc residue		Residue from KOH digestion of talc	0.4	±0.3	7	Second digestion of sediment residue

Note: N = number of analyses.