The northeastern U.S. is home to various accreted terranes, including arc island land masses. Northern Maine, including Bald Mountain and the surrounding Munsungun anticlinorium, contains belts of Ordovician arc volcanic rocks that were later deformed and metamorphosed and are now partly covered with sedimentary rock and glacial deposits. Geologic mapping has identified voluminous explosive facies of pyroclastic rocks, effusive facies of basalt, andesite, and dacite flows, and subvolcanic facies of diabase sills and dikes, as well as a tholeiitic volcanic sequence.
Hydrothermal volcanogenic seafloor polymetallic sulfide systems modified and mineralized these rocks, resulting in deposits not only of copper and zinc, but also critical mineral resources cobalt and tin. Cobalt and tin are important components of rechargeable batteries and superalloys, playing key roles in technology ranging from modern electronics to renewable energy to advanced defense systems. Whereas several deposits in the region have been identified, it is anticipated that there are others nearby. The presence of sedimentary cover, however, conceals interesting and important geologic features such as contacts between different rocks, folds and faults, and alteration patterns that are related to mineral deposits.
Geophysical data that are capable of imaging rocks beneath the surface, such as magnetics and gravity, are needed to better understand the geology of the Munsungun area and surrounding region. As part of its Earth MRI program, the USGS will contract a new high-resolution airborne magnetic and radiometric survey over the region. We seek a Mendenhall Fellow to lead advanced quantitative analyses and interpretation of the new airborne data and other complementary ground data (such as gravity). The Fellow will benefit from collaboration with geologists as part of a larger effort to better understand the subsurface geology of the region as well as interactions with other scientists working within the broader Earth MRI group. Results of this study will help address the following questions:
- What are key geologic features, in three-dimensions, of Bald Mountain and the surrounding region? For example, how deep are the associated volcanic rocks? What is the thickness of the sedimentary and glacial overburden?
- Which areas have been impacted by hydrothermal alteration, and why?
- What are the geologic controls on deposit formation?
- Do the mineralized areas have specific geophysical signatures?
- Are there nearby areas likely to host unknown deposits?
- Why does this region host massive sulfide deposits?
- What can we learn about similar critical mineral deposits elsewhere in the world?
Interested applicants are strongly encouraged to contact the Research Advisor(s) early in the application process to discuss project ideas.
Proposed Duty Station: Lakewood, CO
Areas of PhD: Geophysics, geology, Earth sciences, or related fields (candidates holding a Ph.D. in other disciplines, but with extensive knowledge and skills relevant to the Research Opportunity may be considered).
Qualifications: Applicants must meet the qualifications for: Research Geophysicist.
(This type of research is performed by those who have backgrounds for the occupations stated above. However, other titles may be applicable depending on the applicant's background, education, and research proposal. The final classification of the position will be made by the Human Resources specialist.)
Human Resources Office Contact: Joseline Martinez Lopez, 303-236-9559, jmartinezlopez@usgs.gov
