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Joshua M. Rosera, Ph.D.

Joshua Rosera is a Research Geologist with the USGS Geology, Energy & Minerals (GEM) Science Center in Reston, VA.

I am an economic geologist that is interested in utilizing spatial analysis, geochronology, and radiogenic isotopic measurements to test models about the origins of mineral systems related to continental magma systems. Part of my ongoing work at the USGS is focused on integrating large spatial datasets into tools that can be used to better explore, visualize, and model data related to mineral deposits. This includes developing multivariate tools that can analyze previously underutilized qualitative data attributes in historical mineral deposit datasets, as well as developing data-driven methods to assist in mineral prospectivity mapping and mineral resource assessments.

I completed my M.S. and Ph.D. at the University of North Carolina, where I studied temporal and spatial relationships between caldera-forming silicic magma systems and mineral deposits. My collaborators and I use high-precision U/Pb zircon geochronology to better resolve timescales of magmatism related to mineralization, and where and when these events occur with respect to caldera formation. I am also interested in studying the origins of fluorine enrichment that is observed in numerous magma systems in the Southern Rocky Mountain region. We test hypotheses regarding how these systems achieve high fluorine abundances by analyzing deep crustal xenoliths, and by tracking the sources of fluorine-rich melts with radiogenic isotopes.

Prior to starting my Ph.D., I worked for Chevron as a mine and petroleum geologists. I worked at the Questa molybdenum mine in northern New Mexico up until its final closure in 2014. I spent the next two years in west Texas as an operations geologist where I assisted technical work for a mature waterflood.

Professional Experience

  • Research Geologist (2022-present)

  • Mendenhall Postdoctoral Fellow, U.S. Geological Survey (2020-2022)

  • Graduate Research Consultant, University of North Carolina (2017; 2018)

  • Instructor, University of North Carolina (2016)

  • Research and Teaching Assistant, University of North Carolina (2010-2012; 2016-2020)

  • Earth Scientist, Chevron North America Exploration and Production Company (2014-2016)

  • Mine Geologist, Chevron Mining Inc. (2012-2014)

  • Research and Teaching Assistant, University of Wisconsin – Oshkosh (2008 – 2010)

  • GIS Intern, University of Wisconsin – Oshkosh (2010)

  • GIS Intern, City of De Pere, Wisconsin (2009)

Education and Certifications

  • Ph.D., Geological Sciences, University of North Carolina at Chapel Hill (2020)

  • M.S., Geological Sciences, University of North Carolina at Chapel Hill (2012)

  • B.S., Geology and Geography, University of Wisconsin – Oshkosh (2010)

Affiliations and Memberships*

  • Society of Economic Geologists

  • Geological Society of America

  • Sigma Xi

  • American Geophysical Union

Science and Products

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USGS

Extracting data from maps: applying lessons learned from the AI for Critical Mineral Assessment Competition

This project will share techniques developed in two AI/ML competitions run in Fall 2022, Automated Map Georeferencing, and Automated Map Feature Extraction with USGS stakeholders. We will develop a strategy to operationalize successful approaches, benefiting any activity that uses legacy map data.
By
Community for Data Integration (CDI), Community for Data Integration (CDI)
link

Extracting data from maps: applying lessons learned from the AI for Critical Mineral Assessment Competition

This project will share techniques developed in two AI/ML competitions run in Fall 2022, Automated Map Georeferencing, and Automated Map Feature Extraction with USGS stakeholders. We will develop a strategy to operationalize successful approaches, benefiting any activity that uses legacy map data.
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Fluorine-rich mafic lower crust in the southern Rocky Mountains: The role of pre-enrichment in generating fluorine-rich silicic magmas and porphyry Mo deposits

Fluorine-rich granites and rhyolites occur throughout the southern Rocky Mountains, but the origin of F-enrichment has remained unclear. We test if F-enrichment could be inherited from ancient mafic lower crust by: (1) measuring amphibole compositions, including F and Cl contents, of lower crustal mafic granulite xenoliths from northern Colorado to determine if they are unusually enriched in halog
Authors
Joshua Mark Rosera, Ryan Edward Frazer, Ryan D. Mills, Kristin Jacob, Sean P. Gaynor, Drew S. Coleman, G. Lang Farmer
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Geosciences and Environmental Change Science Center

Automated georeferencing and feature extraction of geologic maps and mineral sites

The predictive power of mineral prospectivity analysis depends on high quality, spatially accurate, analysis-ready datasets. Of paramount importance are geologic maps and mineral site data, but the state of readiness for utilizing these datasets remains sub-optimal for advanced computational techniques. As the U.S. Geological Survey (USGS) fulfils its mission to map the distribution of critical mi
Authors
Graham W. Lederer, Joshua Mark Rosera, Margaret A. Goldman, Garth E. Graham, Asitang Mishra, Amanda Towler, Brian Wilson, Dustin Graf, Michael Milano, Elizabeth Roberts, Gabrielle Hedrick, Carsten Oertel, Anastassios Dardas, Thomas McEntee
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center

Genesis of the Questa Mo porphyry deposit and nearby polymetallic mineralization, New Mexico, USA

The Oligocene Latir magmatic center in northern New Mexico is an exceptionally well-exposed volcanoplutonic complex that hosts a variety of magmatic-hydrothermal deposits, ranging from relatively deep, F-rich porphyry Mo mineralization to shallower epithermal deposits. We present new whole-rock chemical and isotopic data for plutonic rocks from the Latir magmatic center, including extensive sampli
Authors
Sean P. Gaynor, Joshua Mark Rosera, Drew S. Coleman
By
Mineral Resources Program, Geology, Energy & Minerals Science Center

Correspondence analysis for mineral commodity research: An example workflow for mineralized calderas, southwest United States

Historical mine and mineral deposit datasets are routinely used to inform quantitative mineral assessment models, but they also can contain a wealth of supplementary qualitative information that is generally underutilized. We present a workflow that uses correspondence analysis, an exploratory tool commonly applied to multivariate abundance data, to better utilize qualitative data in these histori

Authors
Joshua Mark Rosera, Drew S Coleman
By
Geology, Energy & Minerals Science Center, Mendenhall Research Fellowship Program

Mapping multivariate ore occurrence data with correspondence analysis

Correspondence analysis is a multivariate method that can be applied to mineral abundance data. Ore mineral assemblages from broadly underutilized prospect and occurrence data can be treated as geochemical anomalies, projected to low-dimensional space, and returned into map view. This approach could have applications for mineral prospectivity mapping and delineation of permissive areas during mi
Authors
Joshua Mark Rosera
By
Geology, Energy & Minerals Science Center, Mendenhall Research Fellowship Program

R Code Supporting the Manuscript: Using Stochastic Point Pattern Analysis to Track Regional Orientations of Magmatism During the Transition to Cenozoic Extension and Rio Grande Rifting, Southern Rocky Mountains

This repository contains code that supports ongoing research in the southern Rocky Mountains in Colorado and northern New Mexico. This region hosted intracontinental magmatism that developed during a tectonic transition from shortening (Laramide orogeny, ca. 75 to 40 Ma) through extension and rifting. The code in this repository presents a novel approach that uses stochastic weighted bootstrap sim
By
Geology, Energy & Minerals Science Center

Science and Products

*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government