Aeromagnetic and Spectral Expressions of Rare Earth Element Deposits in Gallinas Mountains Area, Central New Mexico, USA

The Gallinas Mountains located in the conjunction of Lincoln County and Torrance County, New Mexico, USA are a series of alkaline volcanic rocks intruded into Permian sedimentary rocks. The Gallinas Mountains area is known to host fluorite and copper as veins containing bastnasite while hydrothermally altered rocks associated with iron oxides have been found in the area as well. In this study, multispectral band ratio method was used for surface mineral interpretation by processing satellite image, while aeromagnetic inversion method was applied using aeromagnetic data, digital elevation model and physical properties for 2-D subsurface structure modeling. Bastnasite has higher magnetic susceptibility than the host rocks and surrounding sedimentary rock whereas magnetization of iron oxides (magnetite & hematite) is much stronger than bastnasite; both of them can contribute to a positive aeromagnetic anomaly. Results of this study hypothesize the possible presence of mineralogies and lithologies among the Gallinas Mountains area, indicating the presence of a positive magnetic anomaly that is possibly resultant from both bastnasite and iron oxides