A COMBINED U-PB, HF, AND O IN ZIRCON ISOTOPIC STUDY OF THE NORTHERN SIERRA MADRE OCCIDENTAL SILICIC LARGE IGNEOUS PROVINCE
We are analyzing zircon separated from volcanic rock samples collected over a 40 year period by research groups at UT Austin, UT San Antonio, UNAM, and UCSB. We have selected samples with existing radiometric (e.g., Ar-Ar, K-Ar), geochemical, and isotopic data; and where possible, from lavas and ignimbrites with known sources - some of the ca. 40 known calderas out of the 100s that probably exist. We will analyze for dO in zircon and dO in quartz at the University of Wisconsin by SIMS and laser fluorination, respectively. U-Pb, Hf and trace element analyses will be conducted by LA-ICP-MS at Washington State University.
Here we present details of our sample suite, including location, age, and whole-rock geochemistry.