Critical elements are essential to the modern economy and have potential supply chain disruptions, but compared to most base and precious metals, little work has been done in understanding ore-grade enrichments. Carbonatites are the primary source of the worlds light rare earth elements and niobium, and a potential source for heavy rare earths, scandium, tantalum, and thorium. Project objectives are 1) to evaluate at a global scale the controls that determine whether a carbonatite is enriched in critical elements or not, 2) to determine which mineral(s) host the critical elements in an ore zone and controls on their distribution, and 3) to determine the fluid composition responsible for rare earth element transport and enrichment.

Science Issue and Relevance
Critical elements are essential to the economy and have potential supply chain disruptions but compared to most base (common and inexpensive) and precious metals, little work has been undertaken to 1) determine favorable environments for exploration, 2) identify where these elements reside when enriched. Critical element enrichment in carbonatites is extremely complex and poorly understood, and 3) characterize the chemistry of fluids that transport and concentrate REEs in high-grade and high-tonnage carbonatite complexes.
Methods to Address Issue
Our project's objectives are to determine the processes responsible for critical-element enrichments in carbonatites. Elements of interest include neodymium (Nd), dysprosium (Dy), terbium (Tb), yttrium (Y), niobium (Nb), scandium (Sc), and tantalum (Ta), with other elements included as needed. Three specific objectives are 1) to evaluate at a global scale why some carbonatites are enriched in an element of interest and others are not, 2) to determine where (and why) an element of interest resides in enriched zones, and 3) to determine the composition of the fluids responsible for hydrothermal transport and deposition. This information is key to constraining enrichment processes and extraction requirements. Methods to achieve this include: integrated chemical petrographic, scanning electron microscopy, cathodoluminescence spectroscopy, mineral chemistry, isotopic characterization, fluid inclusion microthermometry, and laser Raman spectroscopy.
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
Below are data releases associated with this project.
Whole-rock geochemical data for the Bear Lodge alkaline complex, Wyoming: 2009 - 2013
Below are publications associated with this project.
The ~1.85 Ga carbonatite in north China and its implications on the evolution of the Columbia supercontinent
- Overview
Critical elements are essential to the modern economy and have potential supply chain disruptions, but compared to most base and precious metals, little work has been done in understanding ore-grade enrichments. Carbonatites are the primary source of the worlds light rare earth elements and niobium, and a potential source for heavy rare earths, scandium, tantalum, and thorium. Project objectives are 1) to evaluate at a global scale the controls that determine whether a carbonatite is enriched in critical elements or not, 2) to determine which mineral(s) host the critical elements in an ore zone and controls on their distribution, and 3) to determine the fluid composition responsible for rare earth element transport and enrichment.
Sources/Usage: Public Domain. Visit Media to see details.SEM backscattered electron image of REE fluorocarbonates in barite beforsite unit of Elk Creek carbonatite. From Verplanck and others, 2015, BCGS Paper 2015-3. Science Issue and Relevance
Critical elements are essential to the economy and have potential supply chain disruptions but compared to most base (common and inexpensive) and precious metals, little work has been undertaken to 1) determine favorable environments for exploration, 2) identify where these elements reside when enriched. Critical element enrichment in carbonatites is extremely complex and poorly understood, and 3) characterize the chemistry of fluids that transport and concentrate REEs in high-grade and high-tonnage carbonatite complexes.
Methods to Address Issue
Our project's objectives are to determine the processes responsible for critical-element enrichments in carbonatites. Elements of interest include neodymium (Nd), dysprosium (Dy), terbium (Tb), yttrium (Y), niobium (Nb), scandium (Sc), and tantalum (Ta), with other elements included as needed. Three specific objectives are 1) to evaluate at a global scale why some carbonatites are enriched in an element of interest and others are not, 2) to determine where (and why) an element of interest resides in enriched zones, and 3) to determine the composition of the fluids responsible for hydrothermal transport and deposition. This information is key to constraining enrichment processes and extraction requirements. Methods to achieve this include: integrated chemical petrographic, scanning electron microscopy, cathodoluminescence spectroscopy, mineral chemistry, isotopic characterization, fluid inclusion microthermometry, and laser Raman spectroscopy.
Return to Mineral Resources Program | Geology, Geophysics, and Geochemistry Science Center
- Data
Below are data releases associated with this project.
Whole-rock geochemical data for the Bear Lodge alkaline complex, Wyoming: 2009 - 2013
This data release contains analytical data from a suite of rock samples collected within the Bear Lodge alkaline complex, northeast Wyoming, which hosts the Bear Lodge rare earth element (REE) deposit. Geochemistry data include major and trace element analytical results for 105 samples including alkaline igneous rocks, carbonatites, and weathered and oxidized samples. Samples were collected from s - Publications
Below are publications associated with this project.
The ~1.85 Ga carbonatite in north China and its implications on the evolution of the Columbia supercontinent
Mantle-derived carbonatites provide a unique window in the understanding of mantle characteristics and dynamics, as well as insight into the assembly and breakup of supercontinents. As a petrological indicator of extensional tectonic regimes, Archean/Proterozoic carbonatites provide important constraints on the timing of the breakup of ancient supercontinents. The majority of the carbonatites repoAuthorsYuling Xie, Yunwei Qu, Richen Zhong, Philip L. Verplanck, Sebastien Meffre, Daoxue Xu