Paleo‐Permeability Structure of the Crustal Section of the Samail Ophiolite Based on Automated Detection of Veins in X‐Ray CT Core Images From the Oman Drilling Project

To assess the paleo-permeability structure of oceanic crust, we used 3-D X-ray Computed Tomography (XCT) images to quantify distribution and geometry mineral veins in core samples from Oman Drilling Project Holes GT1A, GT2A, GT3A, which correspond upper lower crustal sections Samail ophiolite. We developed a new method that automatically detects XCT based on iterative adaption two-step Hough transform combined with multiscale Hessian filtering for identifying an elongate structure. Application allowed us identify number more than 1500 millimeter-scale apertures total length ∼1,200 m. High-CT (HCT) drilled cores can be related relatively high-temperature fluid circulation near mid-ocean ridge, whereas Low-CT (LCT) subsequent low-temperature circulation. Applying fracture fluid-flow models geometric information detected veins, found HCT LCT vein systems both yielded bulk permeability 10−13–10−9 m2 each hole. This indicates millimeter-wide fractures control crustal-scale permeability, even crust. However, these show different depth dependencies anisotropies possibly reflecting spatial variations high-