Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 285-297 |
| Number of pages | 13 |
| Journal | Marine Geology |
| Volume | 30 |
| Issue number | 3-4 |
| DOIs | |
| Publication status | Published - 1979 |
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ASJC Scopus subject areas
- Geochemistry and Petrology
- Geology
- Geophysics
Cite this
Pigeonite-bearing basalts dredged from the Puerto Rico Trench : A microprobe study. / Shibata, Tsugio.
In: Marine Geology, Vol. 30, No. 3-4, 1979, p. 285-297.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Pigeonite-bearing basalts dredged from the Puerto Rico Trench
T2 - A microprobe study
AU - Shibata, Tsugio
PY - 1979
Y1 - 1979
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 -