Phillips, Stephen C; Johnson, Joel (2021): Sediment elemental chemistry, magnetic susceptibility, isothermal remanent magnetization, and age model from NGHP-01 Sites 10 and 16 (offshore Krishna-Godavari Basin, Bay of Bengal) [dataset bundled publication]. PANGAEA, https://doi.org/10.1594/PANGAEA.933230

We present datasets associated with an approach to disentangle detrital and diagenetic influences on magnetic susceptibility in marine sediments in the Bay of Bengal. The goal of the approach is to identify zones in which titanomagnetite has been subject to dissolution and resulting in pyrite precipitation at paleo depths of the sulfate-methane transition zone (SMTZ) or paleo-seep activity. These data are from two sites with cores recovered during the Indian National Gas Hydrate Program Expedition 01 (NGHP-01). We characterize the upper 27 meters below seafloor (mbsf) at Hole NGHP-01-10D (15° 51.8609'N, 81° 50.0749' E, 1035 m water depth) and the upper 73 mbsf at Hole NGHP-01-16A (16° 35.5986' N, 082° 41.0070' E, 1252 m water depth). These sediments were collected using piston coring and extended core barrel coring during drilling on the JOIDES Resolution in June and July of 2006. We present high-resolution measurements of magnetic susceptibility (onboard Geotek multi-sensor core logging) and X-ray fluorescence (Cox Analytical core scanner at Woods Hole Oceanographic Institution, WHOI) for the elements Zr, Rb, Fe, Ti, Ca, and K. Discrete measurements of total organic carbon (TOC) and total sulfur (TS) were measured on powdered sediment samples using a Perkin Elmer CHNS/O 2400 Series II elemental analyzer at the University of New Hampshire (UNH). Grain size was measured using a Beckman Coulter LS 13320 Laser Diffraction Particle Size Analyzer at WHOI. We also present acquisition curves of isothermal remanent magnetization (IRM) from 0 to 1.1T and thermal demagnetization (20 to 580 degrees C) measured across three axes using an HSM2 SQUID spinner magnetometer at UNH. Authigenic carbonate nodules at Site 16 were pulverized and measured by X-ray diffraction at UNH to determine mineralogy. These carbonate powders at Site 16 were analyzed for oxygen and carbon isotopic signature using a Finnegan MAT 253 mass spectrometer with a Kiel IV carbonate preparation device (phosphoric acid at 77 °C) at the University of Michigan. Carbonate powders from Site 10 were analyzed by Finnegan MAT 252 mass spectrometer with a Kiel III carbonate preparation device (phosphoric acid at 70 °C) at Oregon State University (OSU) for oxygen and carbon isotopic signature. We picked mixed planktonic foraminifers (primarily Globigerinoides ruber and Globigerinoides sacculifer) from Site 16 sent them for radiocarbon analysis at National Ocean Sciences Accelerator Mass Spectrometry (NOSAMS) facility at WHOI. The radiocarbon ages were then calibrated using Calib 8.2 and the Marine20 calibration curve. We also picked benthic foraminifers from Site 16 (Hoeglundina elegans and Uvigerina peregrina) for analysis of oxygen and carbon isotopes at the University of Michigan.