Pajarito Mountain

Region West, Southwest
Mineral systems
Deposit types
Critical minerals
Other minerals

Information leading to the delineation of this focus area

Basis for focus area Alkaline/peralkaline igneous rocks (HREE); Proterozoic Y-Zr deposits in alkaline rocks. Several varieties of layered syenite, quartz syenite, nepheline syenite, alkali granite, pegmatites, and gabbro are exposed at Pajarito Mountain and are intruded by pegmatite and gabbroic dikes (Sherer, 1990; Berger, 2018). Syenite intrusion with random primary igneous disseminations of eudialyte. Focus area based on Pajarito Mountains Mining District (McLemore and others, 2005; McLemore, 2010a, 2017).
Identified resources Identified REE-yttrium and zirconium resources; historical production of iron.
Production Minor iron production.
Status Past mining. Drilling in 2013 on Mescalero Indian Reservation (Berger, 2018); drill core are in Denver.
Estimated resources 2.7 million tons at 0.18% Y2O3, 1.2% ZrO2 (Sherer, 1990); this Identified resource from 1990 is probably well short of total resources.
Geologic maps Moore and others (1988), scale 1:24,000; Kelley (1971), scale 1:252,430.
Geophysical data Inadequate aeromagnetic and aeroradiometric coverage.
Favorable rocks and structures Complex of Mesoproterozoic syenite, quartz syenite, nepheline syenite, gabbro, pegmatites, and alkali granite.
Deposits Pajarito Mountain (MRDS dep_id: 10125914; USMIN Site_ID: NM00019).
Evidence from mineral occurrences MRDS; USMIN.
Geochemical evidence Berger (2018) reports up to 3.8% TREE from drill core. Yttrium and Zr are found in the silicate mineral eudialyte, which is disseminated as a rock-forming mineral in syenite, quartz syenite, and alkali granite.
Geophysical evidence Inadequate aeromagnetic coverage.
Evidence from other sources None.
Comments Best potential for REE development in New Mexico is the disseminated Y-Zr deposits in syenites at Pajarito Mountain, carbonatites, and REE-Th-U hydrothermal vein and breccia deposits (McLemore, 2014). Area is on the Mescalero Indian Reservation.
Cover thickness and description No cover in the area of the resource drilled by Molycorp and announced in 1989.
Authors Lukas Zurcher, Timothy S. Hayes, Mark E. Gettings, Virginia T. McLemore, Joshua M. Rosera.
New data needs Detailed 1:12,000 mapping.
Geologic mapping and modeling needs This area has never been mapped at the 1:24,000 scale. It is included on the regional scale maps of Kelley (1971).
Geophysical survey and modeling needs High resolution geophysical coverage needed.
Digital elevation data needs Lidar complete over eastern portion; in progress over western.