Summary: International Geology Review, Vol. 48, 2006, p. 778­790.
Copyright © 2006 by V. H. Winston & Son, Inc. All rights reserved.
0020-6814/06/891/778-13 $25.00 778
P-T Path for Ultrahigh-Pressure Garnet Ultramafic Rocks of the
Cuaba Gneiss, Rio San Juan Complex, Dominican Republic
RICHARD N. ABBOTT, JR.,1
Department of Geology, Appalachian State University, Boone, North Carolina 28608
GRENVILLE DRAPER,
Department of Earth Sciences, Florida International University, Miami, Florida 33199
AND BONNIE N. BROMAN
Department of Geology, Appalachian State University, Boone, North Carolina 28608
Abstract
Ultrahigh-pressure (UHP) rocks in the Cuaba Gneiss include Grt ultramafic rocks, mafic eclog-
ite, and partially retrograded equivalents. The Grt ultramafic rocks (Spl-bearing Grt peridotite, Spl-
bearing Grt clinopyroxenite, Crn-Spl­bearing Grt clinopyroxenite) are of igneous origin, with mag-
matic conditions of P > 3.5 GPa, T > 1550°C. The magmatic history took place in the asthenosphere.
New chemical analyses of minerals give the following subsolidus conditions: Grt peridotite, 3.0­4.2
GPa, 838-867°C; Grt clinopyroxenite (Grt + Cpx + Spl + Crn), 2.75 GPa, 807°C. The ultramafic
rocks are associated with partially retrograded eclogite, interpreted as deep-subducted oceanic
crust. New chemical analyses of minerals in the eclogite give conditions that relate to the retrograde

Source: Abbott Jr., Richard N. - Department of Geology, Appalachian State University

Collections: Geosciences