Subsurface volumetric estimates of ultramafic and mafic rocks in the Livengood Terrane, Central Alaska: implications for carbon mineralization

Abstract Mafic and ultramafic rocks are sources of critical minerals and also provide a medium to securely store CO 2 . The objective of this study is to delineate the geometry and assess the volumes of ultramafic rocks in the Livengood Terrane in central Alaska using high-resolution aeromagnetic, petrophysical, and borehole datasets. We analyzed magnetic anomalies using 3D inversion using constraints from previous outcrop and petrophysical data. The high-resolution aeromagnetic anomaly map reveals elongated high-magnetic signatures extending from northeast corner to southwest corner of the study area, which are associated with the Cambrian Cascade ophiolite assemblage of the Livengood Terrane. 3D magnetic inversion results show three high-susceptibility bodies (HS-1 to HS-3) with magnetic susceptibility values ranging from 0.03 to 0.055 SI, and a combined estimated volume of ~ 12 km 3 . Estimates of in situ carbon mineralization based on laboratory experiments and stoichiometric calculations indicate a plausible CO 2 storage capacity of approximately 250 Mt to 1 Gt CO 2 . These findings highlight first-order target areas in the Livengood Terrane for initial assessment of carbon mineralization potential. Furthermore, this study demonstrates that geophysical inversion of magnetic data can help guide site selection and development for carbon mineralization.