Where could geologic hydrogen generation happen in UAE? Mapping serpentinization in the ophiolite blocks using MT phase tensors

Geologic hydrogen has emerged as a primary energy source, drawing growing interest from the scientific community and the energy sector. One of the primary geochemical mechanisms for natural hydrogen generation is serpentinization, which is the hydration of mafic and ultramafic rocks. The United Arab Emirates (UAE) is home to one of the largest ophiolite blocks in the world, making it a promising area for geologic hydrogen exploration. In this study, we apply magnetotelluric (MT) phase tensor analysis to detect electrical anisotropy associated with serpentinization in the mantle peridotite sequence. The alignment of olivine crystals and hydrous minerals such as serpentine impart electrical anisotropy to these rocks. Current approaches for detecting serpentinization have primarily focused on changes in bulk physical properties, often overlooking the directional dependencies and complexities introduced by anisotropy. In this research, we introduce a novel geophysical framework based on the phase tensors, to identify serpentinized zones within source rocks in geologic hydrogen systems and possibly identify potential hydrogen-bearing zones. Using MT field data from the UAE, we demonstrate that phase tensor analysis effectively identifies anisotropic conductivity zones associated with serpentinization. The MT phase tensor approach we propose can support assessment of geologic hydrogen generation and its lifecycle.