Sediment cores were collected via wireline coring tools (advance piston coring, extended core barrel coring, and pressure coring) and cut into sections at sea. Hole H002 is located at 26.66228° latitude and -91.67601° longitude at the seafloor. Hole H003 is located at 26.66263° latitude and -91.67599° latitude at the seafloor. Whole round sections were capped, taped, and stored refrigerated at 4°C. Once transported to shore-based science operations in Salt Lake City, the core sections were split lengthwise, and samples were collected from the working half of the core sections at room temperature conditions within hours of splitting.
Samples for dual-frequency magnetic susceptibility measurements were collected in 8cm3 (2 x 2 x 2 cm) plastic paleomagnetic cubes following IODP procedures (Richter et al., 2007). Samples were sampled immediately after core splitting, then weighed in tared plastic paleomagnetic cubes. Each sample was measured that same day at room temperature using a Bartington MS3 Magnetic Susceptibility Meter with a Bartington MS2B Dual-Frequency Magnetic Susceptibility Sensor following the steps set forth in the operating manual (Bartingon Instruments, 2022). Each sample was measured for low frequency (LF) magnetic susceptibility at 465 Hz with an air blank before and after the measurement. Each sample was measured for high frequency (HF) magnetic susceptibility at 4650 Hz with an air blank before and after the measurement. The LF and HF values were normalized on a mass-basis using the instrument software. Frequency dependence of magnetic susceptibility was calculated in the instrument software using the formula of Dearing et al. (1996).
Reference:
Bartington Instruments, 2022, MS3 Magnetic Susceptibility Meter,
https://www.bartingtondownloads.com/wp-content/uploads/OM3227.pdf. Accessed June 5, 2025
Dearing, J.A., Dann, R.J.L., Hay, K., Lees, J.A., Loveland, P.J., Maher, B.A., and O’Grady, K., 1996, Frequency-dependent susceptibility measurements of environmental materials: Geophysical Journal International, v. 124, p. 228-240,
https://doi.org/10.1111/j.1365-246X.1996.tb06366.x
Richter, C., Acton, G., Endris, C., and Radsted, M., 2007, Handbook for shipboard paleomagnetists: ODP Technichal Note, 34,
https://doi.org/10.2973/odp.tn.34.2007