Dataset: Cocos Ridge Solid Phase Data
Deployment: SR2113

Porosity was obtained by mass of water loss upon drying and assigned a standard salinity (34.6 ppt) and sediment grain density (2.6 g/cm3). Bulk sediment samples were dried in an oven at 50°C for 72 h and then homogenized for TC and mineralogical analyses.

2-10 mg of the samples were used for PIC (% CaCO3) and delta 13C of PIC and analyzed on a Picarro Cavity Ring-Down Spectrometer (G2131-i) with Liaison autosampler, following acidification. TC and delta 13C of TC measurements were conducted using an Elemental Analyzer (EA, Costech) coupled to a Picarro Cavity Ring-Down Spectrometer (G2131-i).

Particulate Organic Carbon (POC) was calculated by subtracting PIC from TC. Uncertainties in PIC and TC concentrations were evaluated based on the average offset between duplicate sample measurements and were identified to be ± 0.04 % PIC (7 pairs of duplicates) and ± 0.03 % TC (5 pairs of duplicates). Uncertainty in delta 13C was evaluated based on the standard error of the measured optical calcite standard and was 0.02 ‰.

Mineralogy of the sediment was measured with a Bruker D8 Advance X-Ray Diffraction (XRD). Roughly 200 mg of each ground sediment sample was mounted onto a rotating disc and scanned for ~1 h. Data analysis was conducted using the software Jade.