NSF Award
2503213
Metals are critical components of modern society. Aside from recycling, metals are recovered from ore deposits such as magmatic sulfide systems that often formed close to the surface and thus provide relatively easy access to metals like nickel and copper. Because ore deposits are non-renewable, we must find (at least) one new deposit for each exhausted resource to guarantee a steady metal supply in the future. Currently, mineral exploration efforts focus mostly on the upper crust because this approach has worked well over the past century. However, a recent decline in new discoveries implies that most of the deposits near the surface have already been found. Consequently, the opening of search space deeper in the Earth is necessary to guarantee a steady metal supply. This project will address this issue by investigating the formation of a series of variably metasomatized magmatic sulfide deposits in the Ivrea-Verbano Zone in Italy. These deposits formed in the deep crust and were tectonically uplifted to mineable levels. Although the deposits were previously mined for nickel and copper, surprisingly little is known about how they (and similar deposits elsewhere) originally formed. This project will use the deposits in the Ivrea-Verbano Zone to better constrain how and where such deposits preferentially form, particularly focusing on the role of mantle metasomatism in deep crustal ore formation. The findings will provide an important step toward including such deposits in future exploration models. The research will be integrated with an educational component that will reach K-12, undergraduate and graduate students. A high school outreach program in collaboration with Project Lead The Way will use examples from this project to highlight geoscience career paths that K-12 students may initially not be aware of, particularly in rural Missouri. The PI will also incorporate aspects of the proposed research into a summer training program for undergraduate students to help students prepare for a post-baccalaureate geoscience career. Furthermore, two graduate students will be actively involved in the research component. <br/><br/>The Ivrea-Verbano Zone is a well-preserved cross section of the subcontinental lithospheric mantle and lower continental crust that outcrops subvertically and therefore allows for comprehensive studies of deep lithospheric mass transfer. Previous studies on the Ivrea-Verbano Zone have significantly contributed to our understanding of the lower continental lithosphere. However, research that focuses on the source of metalliferous hydrous melts/fluids, and their role in the transport and local deposition of metals (i.e., ore deposits) is rare. To address this knowledge gap, this project will investigate different localities in the Ivrea-Verbano Zone that represent variable degrees of metasomatism and sulfide mineralization: (1) strongly metasomatized / highly mineralized pipes, (2) un-metasomatized / moderately mineralized sills/intrusions, and (3) a strongly metasomatized / sulfide-poor mantle peridotite. Field studies will be integrated with petrographic observations, bulk rock, mineral and fluid inclusion analyses, isotopic (Cu, Sm-Nd) and geochronological studies. The proposed research will provide new insight into (1) the physical and chemical processes that produce, transport and concentrate fluids and metals in the deep lithosphere; and (2) the spatial and temporal scales of such processes. The PI is actively recruiting K-12 teachers, undergraduate and graduate students to be involved in this project. The goal of the K-12 outreach program is to raise awareness for geoscience disciplines and to encourage students to consider geoscience or other STEM career paths. Undergraduate and graduate student projects will be individually tailored to prepare each student for a career path of their choosing in academia, federal/state agencies, or the private sector.<br/><br/>This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.
