Project Overview
Origin of Iron Ore Deposits in the Adirondack Mountains
Department(s)
Earth and Environmental Geosciences
Abstract
Metamorphic rocks of the Eastern Adirondack Mountains (New York) are home to an important iron mining district that was active from the early 1800s through 1971, and had its peak during World War II. Iron ore at these mines is mostly magnetite (Fe3O4), commonly associated with apatite. The ease of separation using magnetic methods initially made these high-grade ores very attractive, but competition with mines in the Midwest and relatively small deposit sizes led to the eventual decline of the district. Currently, waste rocks at these sites are being investigated as a possible source for Rare Earth Elements (primarily in apatite), an important component of rechargeable batteries and magnets used for wind turbines.
The origin of these ore deposits is controversial. They are associated with the regionally-widespread Lyon Mountain granite, an igneous suite that intruded relatively late in the mountain building event which caused much of the structural deformation and metamorphism in the Adirondacks. These granites have been hydrothermally altered by multiple pulses of K- and Na-rich fluids, which in some places seems to affect ores, so a hydrothermal origin for the ore appears consistent with field evidence. In other places, mineral assemblages point towards a higher-temperature origin for ore formation, perhaps more directly related to the granitic magmas. The goal of this project is to use the stable isotopes of oxygen and iron in these ores as a fingerprint to better understand the temperature of ore deposition and the origin of fluids in these ore deposits.
Students will visit several of these ore deposits in the field (in collaboration with the US Geological Survey), and collect a suite of samples for laboratory work. Samples will be characterized using Colgate scanning electron microscope, and mineral separates will be prepared for O and Fe isotope work, which will be done at the University of Wisconsin and Rutgers University.
Student Qualifications
Geol 201 (Mineralogy and Geochemistry) is required, and Geol 320 (Techniques of Field Geology) is recommended. The Department of Earth and Environmental Geosciences encourages all students interested in summer research opportunities to meet with potential faculty supervisors before submitting their applications.
Number of Student Researchers
1 or 2 student
Project Length
7 weeks