See more from this Division: Topical Sessions
See more from this Session: Recent Advances in the Understanding of Adirondack and Southern Grenville Province Tectonics I: In Honor of James McLelland
Abstract:
The sporadic distribution of coronas in the BCAC remains problematic. The majority of samples are corona-free, consisting of plagioclase with scattered grains of hornblende plus minor biotite and Fe-Ti oxide. The normative compositions of these corona-free rocks appear the same as those with coronas; hence, it is difficult to appeal to bulk-compositional effects. Regional variations in P-T conditions or localized access to fluids are also possible, but it is equally likely that the corona-forming reactions went to completion, eliminating petrographic evidence for the former presence of olivine and/or orthopyroxene. The timing, exact P-T conditions, and details of the corona-forming reactions remain the subject of ongoing investigations.
See more from this Division: Topical Sessions
See more from this Session: Recent Advances in the Understanding of Adirondack and Southern Grenville Province Tectonics I: In Honor of James McLelland