Concealed Rare Earth Element (REE) Terranes in the Southern Basin and Range Geologic Province

Science Center Objects

The project is developing an understanding of the types, sizes, and spatial distribution of rare earth element (REE) related deposits in the southern Basin and Range geologic province to help ensure the availability of rare earth elements to the U.S.

Science Issue and Relevance

The Department of the Interior Secretarial Order 3359 'Critical Mineral Independence and Security' directed the USGS to develop a plan to improve the Nation's understanding of domestic critical mineral resources. The southern Basin and Range geologic province contains multiple types of rare earth element (REE) deposits and occurrences. This project is a one-year effort aimed at increasing the understanding of rare earth element terranes in the southern Basin and Range geological province based on the age of deposits and occurrences.

Methodology to Address Issue

Most of the rare earth element deposits associated with Tertiary alkaline igneous rocks are found in the Trans-Pecos of West Texas and parts of southeastern New Mexico while the older rare earth element deposits are found scattered throughout Arizona and New Mexico. We will summarize existing data and prioritize regions for new geophysical data acquisition through the Earth Mapping Resources Initiative (Earth MRI).

A focus (spatial and deposit type) for the older deposits needs to be found; therefore two tasks will address these
objectives based on deposit ages:

  • Concealed terranes for rare earth element deposits associated with Tertiary igneous rocks (Texas and New Mexico): the initial focus is a series of rare earth element enriched ~ 34-36 Ma intrusive rhyolites and syenites in the Trans-Pecos of west Texas and New Mexico which includes the Round Top deposit; the Gallinas Mountains in New Mexico are also being looked at.
  • Concealed terranes for rare earth element deposits associated with Proterozoic to Cambrian alkaline igneous rocks (New Mexico and Arizona): focus on the alkaline igneous and carbonatite rocks, primarily in New Mexico including the Lemitar Mountains.

 

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