Research Interests - William C. McIntosh, New Mexico Tech Earth & Environmental Science

Research Interests
William C. McIntosh, Associate Professor of Geochemistry

My chief ongoing research interests involve volcanism of the southwestern U.S. and Antarctica during the last 40 million years. Both regions have experienced extensive volcanic activity well away from active plate tectonic margins, instead related to rifting and extension within continental plates.

The two main tools that I have been using to unravel the volcanic history of these regions are 40Ar/39Ar geochronology and paleomagnetism. Recent developments in the 40Ar/39Ar dating method allow highly increased precision as well as dating of very young and very small samples. This opens up exciting new possibilities, such as detailed reconstruction of the eruptive history of 30 million year old calderas, or using 10,000 year old ash deposits in Antarctic ice cores to help understand the timing of changing global climates.

The combination of volcanic geology, 40Ar/39Ar dating, paleomagnetism, and other geochronologic techniques has opened up a wealth of other research avenues, including calibration of the time scale of worldwide geomagnetic reversals, and an attempt to determine the uplift history of the Tibetan Plateau.

Bill McIntosh on floor of main crater of Mt Erebus Volcano in Antarctica

Bill McIntosh on the floor of the main crater of the Mt. Erebus Volcano in Antarctica. A large block from an earlier eruption is in the foreground. (photo courtesy Nelia Dunbar, 1983)