Joshua M. Rosera, Ph.D.

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.