11:15 AM - 11:30 AM
[SCG49-14] Physical properties of the Moho TZ: Implications from ICDP Oman Drilling Project Phase I & II on-board measurements
Keywords:ICDP, Oman Drilling Project, ophiolite, Moho TZ, Oceanic crust
Whole-round data, including X-ray CT images, natural gamma radiation (NGR), gamma ray attenuation (GRA) density, magnetic susceptibility (MS), P-wave velocity (Vp) and noncontact electrical resistivity were obtained. Split core color spectroscopy data were also collected. Magnetic susceptibility, electrical resistivity under both nominally dry and brine-saturated conditions, P-wave velocity, bulk/grain density, porosity and thermal conductivity were measured in discrete samples. Nearly 100% core recovery allowed us to take a large data set of petrophysical data on the cores from Oman ophiolite including fault zones and highly altered intervals.
Generally, gabbroic rock types have higher density, P-wave velocity, and electrical resistivity, and lower porosity than ultramafic lithologies. Serpentinized dunite have lower density, P-wave velocity and electrical resistivity, and higher porosity than serpentinized harzburgite, and these physical properties are correlated with magnetic susceptibility, probably due to crystallization of magnetite during alteration. Average X-ray CT values are also correlated with many other physical properties in most lithologies. Those physical property data and the lithological characteristics of the Moho transition zone in the Oman ophiolite revealed apparent difference and similarities with the oceanic data, especially in the seismic profiles from the oceanic plate. In this paper, we would like to compare the data from ocean drilling, Oman Drilling and seismic profiles.