TY - JOUR
T1 - A petrological experiment on Emeishan basalt
T2 - Implications for the formation of syenite from the Baima igneous complex
AU - Hsia, Wen Yu
AU - Gregory Shellnutt, J.
AU - Liu, Teh Ching
AU - Iizuka, Yoshiyuki
N1 - Funding Information:
for their comments that helped to improve the manuscript and Kuo-Lung Wang for editorial handling. The authors are appreciative of the laboratory assistance of Chian-Huei Hung, Hui-Ho Hsieh, and Yu-Shiang Wang. This research was supported by funding provided by Ministry of Science and Technology projects 107-2628-M-003-003-MY3 to JGS and 107-2116-M-003 to YI.
Publisher Copyright:
© 2021 Chinese Geoscience Union. All rights reserved.
PY - 2021/6
Y1 - 2021/6
N2 - The Baima igneous complex (BIC) consists of a cumulate layered gabbroic unit, an Fe-Ti oxide ore zone, and an isotropic quartz syenite. The formation of the BIC is attributed to a variety of petrological processes including: silicate immiscibility, fractional crystallization, and fluxing of fO2 by either internal or external factors. This study attempts to determine if a parental magma similar to high-Ti Emeishan basalt can produce the syenitic rocks of the BIC. The experimental results at atmospheric pressure show that the liquidus temperature and solidus temperature of the basaltic melt are estimated to be 1303 and 1120°C. The crystallization sequence is: titanomagnetite, clinopyroxene (Wo43-47En32-45Fs11-23), and plagioclase (An65-31). The residual liquid composition, represented by quenched glass, evolves from lower SiO2 (~45 wt%) values to higher values (~60 wt%) with corresponding decreases in Ti, Fe, Mg, Ca and increases of Na and K. The results show that a starting composition of high-Ti basalt from the Emeishan large igneous province can produce evolved silicic liquids that resemble the compositions of microgranular enclaves from the Baima syenitic unit.
AB - The Baima igneous complex (BIC) consists of a cumulate layered gabbroic unit, an Fe-Ti oxide ore zone, and an isotropic quartz syenite. The formation of the BIC is attributed to a variety of petrological processes including: silicate immiscibility, fractional crystallization, and fluxing of fO2 by either internal or external factors. This study attempts to determine if a parental magma similar to high-Ti Emeishan basalt can produce the syenitic rocks of the BIC. The experimental results at atmospheric pressure show that the liquidus temperature and solidus temperature of the basaltic melt are estimated to be 1303 and 1120°C. The crystallization sequence is: titanomagnetite, clinopyroxene (Wo43-47En32-45Fs11-23), and plagioclase (An65-31). The residual liquid composition, represented by quenched glass, evolves from lower SiO2 (~45 wt%) values to higher values (~60 wt%) with corresponding decreases in Ti, Fe, Mg, Ca and increases of Na and K. The results show that a starting composition of high-Ti basalt from the Emeishan large igneous province can produce evolved silicic liquids that resemble the compositions of microgranular enclaves from the Baima syenitic unit.
KW - A-type syenite
KW - Baima igneous complex
KW - Emeishan large igneous province
KW - Fe-Ti-oxide deposit
KW - Layered gabbroic intrusion
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U2 - 10.3319/TAO.2021.01.30.01
DO - 10.3319/TAO.2021.01.30.01
M3 - Article
AN - SCOPUS:85113699183
VL - 32
SP - 319
EP - 338
JO - Terrestrial, Atmospheric and Oceanic Sciences
JF - Terrestrial, Atmospheric and Oceanic Sciences
SN - 1017-0839
IS - 3
ER -