TY - JOUR
T1 - Pigeonite-bearing basalts dredged from the Puerto Rico Trench
T2 - A microprobe study
AU - Shibata, Tsugio
N1 - Copyright:
Copyright 2014 Elsevier B.V., All rights reserved.
PY - 1979/3
Y1 - 1979/3
N2 - A microprobe study was carried out on zoned clinopyroxene, composed of a pigeonite core mantled by augite, and plagioclase in six tholeiitic basalts dredged from the Puerto Rico Trench (20° 06.8′N, 65° 06.5′W). The pigeonite cores are characterized by high magnesium contents [ Fe Fe + Mg = 0.19 on the average]; their crystallization temperatures based on the three-pyroxene geothermometer are thus estimated to be higher than those of the well-studied tholeiitic pyroxene assemblages (Hakone, Weiselberg, Mull, Skaergaard, and Bushveld). It is suggested from textural and chemical relationships that pyroxene crystallization started first with precipitation of pigeonite followed by simultaneous precipitation of pigeonite and augite and finally by crystallization of augite alone in the groundmass.
AB - A microprobe study was carried out on zoned clinopyroxene, composed of a pigeonite core mantled by augite, and plagioclase in six tholeiitic basalts dredged from the Puerto Rico Trench (20° 06.8′N, 65° 06.5′W). The pigeonite cores are characterized by high magnesium contents [ Fe Fe + Mg = 0.19 on the average]; their crystallization temperatures based on the three-pyroxene geothermometer are thus estimated to be higher than those of the well-studied tholeiitic pyroxene assemblages (Hakone, Weiselberg, Mull, Skaergaard, and Bushveld). It is suggested from textural and chemical relationships that pyroxene crystallization started first with precipitation of pigeonite followed by simultaneous precipitation of pigeonite and augite and finally by crystallization of augite alone in the groundmass.
UR - http://www.scopus.com/inward/record.url?scp=0018439761&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0018439761&partnerID=8YFLogxK
U2 - 10.1016/0025-3227(79)90020-3
DO - 10.1016/0025-3227(79)90020-3
M3 - Article
AN - SCOPUS:0018439761
VL - 30
SP - 285
EP - 297
JO - Marine Geology
JF - Marine Geology
SN - 0025-3227
IS - 3-4
ER -