Grain-size data from core S3-15G, Monterey Fan, Central California

Acquisition of core. Core S3-15G was collected on May 31, 1978 using a gravity corer from the R/V Sea Sounder at a water depth of 3491 m.

Grain-size distributions determined. The grain-size distributions of samples were determined in the USGS Pacific Coastal and Marine Science Center sediment lab. Approximately 20 g of sediment was sub-sampled and 10 mL of 35 percent hydrogen peroxide was added to remove organic material in the sample. The sample was heated at 250 degrees C to remove any remaining hydrogen peroxide and was placed in an ultrasonic bath to liberate the fine fraction. Subsequently, the sample was centrifuged for 1.5 hours to remove soluble salts. Samples were funneled through 2 mm and 63 um sieves to separate the gravel (greater than 2 mm), sand (63 um to 2 mm), and mud (less than 63 um). The sand and gravel fractions were dried in an 80 degree C oven and weighed. Five mL of sodium hexametaphosphate was added to the mud fraction and a 20 mL aliquot was taken from a 1 L graduated cylinder to determine the weight of the mud. The particle-size distribution of the mud and sand fractions was analyzed separately using a Beckman Coulter LS 13 320, and the gravel, sand, and mud results were integrated into a single grain-size distribution for each sample.

INTERPOLATED SIZES WITH COLUMN HEADING CORRECTION: Grain sizes at select cumulative percentage values (D) were calculated by the PCMSC Sediment Lab software pcSDSZ version 2.00 using a polynomial interpolation between phi bins bracketing the specified D value. Grain sizes were converted into units of millimeters (mm) using the formula mm=reciprocal of 2(exponent)phi. Grain sizes at D5, D10, D16, D25, D50, D75. D84, D90, and D95 are reported in phi and millimeter units. PCMSC Sediment Lab data reports issued between February 2011 and August 2022 were revised so that the column headers for the Interpolated Sizes in millimeter units (mm) were transposed from increasing to decreasing D values to correctly reflect the columns of data. This revised metadata shows the column heading correction, which also appears in the corresponding revised data table.