Third hole planned at Valles Caldera

Abstract

Valles caldera, N. Mex., is the culmination of more than 13 million years of volcanism in the Jemez volcanic field and is an excellent model for resurgent calderas and for the high‐temperature geothermal systems found with them. This month one of the biggest diamond drills in the world will start the third research core hole in the caldera. Valles Caldera 2B will be the tenth core hole in the Department of Energy's Continental Scientific Drilling Program.CSDP drilling in the 1.1‐million‐year‐old caldera began in 1984 in the southwest moat zone when the research hole Valles Caldera 1 was continuously cored to 856 m. VC‐1 intersected a hydrothermal outflow plume from the deep geothermal system. Data indicate multiple episodes of hydrothermal activity in the volcanic field's history, as well as multiple episodes of rhyolite magma generation during evolution of the caldera. The June 10, 1988 (vol. 63), issue of Journal of Geophysical Research—Solid Earth and Planets carried a special section on results from VC‐1.