U-Th-Pb Geochronology of the Mentor Anorthosite Intrusive Complex (MAIC) and Regional Plutonic Units

This U.S. Geological Survey (USGS) data release accompanies planned publication 'Geophysical architecture and geochronology of the Neoarchean Mentor anorthosite intrusive complex, northwestern Minnesota: largest anorthosite complex of the Superior Province?'. The data release includes laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) U-Pb zircon geochronology data for eight samples from the Mentor anorthosite intrusive complex (MAIC) and regional plutonic rocks, northwestern, Minnesota, USA. The samples were analyzed to (1) determine the age of the Mentor megacrystic anorthosite unit, and (2) provide the first modern regional U-Pb geochronology for plutonic rocks and area that is entirely concealed and is regionally where the Wawa, Quetico, and Wabigoon subprovinces are juxtaposed in close proximity. The MAIC is interpreted from aeromagnetic, gravity, and borehole data to extend over an area of 640 square kilometers, making it the largest known anorthosite complex of the Superior Province.