Low-temperature eclogite-facies bauxite from the Red River shear zone in Vietnam

Its evolution and significance

Nobuhiko Nakano, Yasuhito Osanai, Nguyen Van Nam, Tran Van Tri

研究成果: ジャーナルへの寄稿記事

3 引用 (Scopus)

抄録

We report first finding of low-temperature eclogite-facies metamorphism from the Red River shear zone in northern Vietnam that has been known as the Paleogene high-temperature metamorphic belt. The rock is extremely aluminous (50.13 wt% Al2O3) and oxidized [Fe3+/(Fe3+ + Fe2+) = 0.89] emery-type rock. Its composition is also characterized by very low SiO2, CaO, and Na2O with high concentrations in high field strength elements, suggesting that the protolith is lateritic bauxite. The analyzed rock is composed mainly of porphyroblastic titanomaghemite, kyanite, allanite, and chloritoid with abundant fine-grained corundum in the matrix. The mineral paragenesis and phase equilibria modeling suggest that the aluminous rock underwent a clockwise pressure-temperature trajectory with the peak metamorphic condition corresponding to low-temperature eclogite- facies approximately 520-550 °C at 1.2-1.5 GPa. Monazite U-Th-Pb dating constrains the timing of the metamorphism to be older than 214 Ma. Our results require two geological events; 1) tropical weathering and bauxitization on the erosional surface, and 2) pre-Late Triassic subduction of supracrustal materials most likely during the Permo-Triassic collisional events in East and Southeast Asia. Our study provides the first evidence for the subduction of supra-continental crustal materials up to 40-50 km depth during the collision between the Indochina and South China blocks.

元の言語英語
ページ(範囲)196-210
ページ数15
ジャーナルJournal of Mineralogical and Petrological Sciences
111
発行部数3
DOI
出版物ステータス出版済み - 7 22 2016

Fingerprint

Vietnam
bauxite
eclogite
rivers
shear zone
rocks
shear
river
rock
metamorphism
Triassic
subduction
Southeast Asia
chloritoid
allanite
corundum
weathering
kyanite
monazite
phase equilibrium

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Geology

これを引用

Low-temperature eclogite-facies bauxite from the Red River shear zone in Vietnam : Its evolution and significance. / Nakano, Nobuhiko; Osanai, Yasuhito; Van Nam, Nguyen; Van Tri, Tran.

:: Journal of Mineralogical and Petrological Sciences, 巻 111, 番号 3, 22.07.2016, p. 196-210.

研究成果: ジャーナルへの寄稿記事

@article{c8147401245f4423b18a58bba3eb552d,
title = "Low-temperature eclogite-facies bauxite from the Red River shear zone in Vietnam: Its evolution and significance",
abstract = "We report first finding of low-temperature eclogite-facies metamorphism from the Red River shear zone in northern Vietnam that has been known as the Paleogene high-temperature metamorphic belt. The rock is extremely aluminous (50.13 wt{\%} Al2O3) and oxidized [Fe3+/(Fe3+ + Fe2+) = 0.89] emery-type rock. Its composition is also characterized by very low SiO2, CaO, and Na2O with high concentrations in high field strength elements, suggesting that the protolith is lateritic bauxite. The analyzed rock is composed mainly of porphyroblastic titanomaghemite, kyanite, allanite, and chloritoid with abundant fine-grained corundum in the matrix. The mineral paragenesis and phase equilibria modeling suggest that the aluminous rock underwent a clockwise pressure-temperature trajectory with the peak metamorphic condition corresponding to low-temperature eclogite- facies approximately 520-550 °C at 1.2-1.5 GPa. Monazite U-Th-Pb dating constrains the timing of the metamorphism to be older than 214 Ma. Our results require two geological events; 1) tropical weathering and bauxitization on the erosional surface, and 2) pre-Late Triassic subduction of supracrustal materials most likely during the Permo-Triassic collisional events in East and Southeast Asia. Our study provides the first evidence for the subduction of supra-continental crustal materials up to 40-50 km depth during the collision between the Indochina and South China blocks.",
author = "Nobuhiko Nakano and Yasuhito Osanai and {Van Nam}, Nguyen and {Van Tri}, Tran",
year = "2016",
month = "7",
day = "22",
doi = "10.2465/jmps.150727",
language = "English",
volume = "111",
pages = "196--210",
journal = "Journal of Mineralogical and Petrological Sciences",
issn = "1345-6296",
publisher = "Tohoku University",
number = "3",

}

TY - JOUR

T1 - Low-temperature eclogite-facies bauxite from the Red River shear zone in Vietnam

T2 - Its evolution and significance

AU - Nakano, Nobuhiko

AU - Osanai, Yasuhito

AU - Van Nam, Nguyen

AU - Van Tri, Tran

PY - 2016/7/22

Y1 - 2016/7/22

N2 - We report first finding of low-temperature eclogite-facies metamorphism from the Red River shear zone in northern Vietnam that has been known as the Paleogene high-temperature metamorphic belt. The rock is extremely aluminous (50.13 wt% Al2O3) and oxidized [Fe3+/(Fe3+ + Fe2+) = 0.89] emery-type rock. Its composition is also characterized by very low SiO2, CaO, and Na2O with high concentrations in high field strength elements, suggesting that the protolith is lateritic bauxite. The analyzed rock is composed mainly of porphyroblastic titanomaghemite, kyanite, allanite, and chloritoid with abundant fine-grained corundum in the matrix. The mineral paragenesis and phase equilibria modeling suggest that the aluminous rock underwent a clockwise pressure-temperature trajectory with the peak metamorphic condition corresponding to low-temperature eclogite- facies approximately 520-550 °C at 1.2-1.5 GPa. Monazite U-Th-Pb dating constrains the timing of the metamorphism to be older than 214 Ma. Our results require two geological events; 1) tropical weathering and bauxitization on the erosional surface, and 2) pre-Late Triassic subduction of supracrustal materials most likely during the Permo-Triassic collisional events in East and Southeast Asia. Our study provides the first evidence for the subduction of supra-continental crustal materials up to 40-50 km depth during the collision between the Indochina and South China blocks.

AB - We report first finding of low-temperature eclogite-facies metamorphism from the Red River shear zone in northern Vietnam that has been known as the Paleogene high-temperature metamorphic belt. The rock is extremely aluminous (50.13 wt% Al2O3) and oxidized [Fe3+/(Fe3+ + Fe2+) = 0.89] emery-type rock. Its composition is also characterized by very low SiO2, CaO, and Na2O with high concentrations in high field strength elements, suggesting that the protolith is lateritic bauxite. The analyzed rock is composed mainly of porphyroblastic titanomaghemite, kyanite, allanite, and chloritoid with abundant fine-grained corundum in the matrix. The mineral paragenesis and phase equilibria modeling suggest that the aluminous rock underwent a clockwise pressure-temperature trajectory with the peak metamorphic condition corresponding to low-temperature eclogite- facies approximately 520-550 °C at 1.2-1.5 GPa. Monazite U-Th-Pb dating constrains the timing of the metamorphism to be older than 214 Ma. Our results require two geological events; 1) tropical weathering and bauxitization on the erosional surface, and 2) pre-Late Triassic subduction of supracrustal materials most likely during the Permo-Triassic collisional events in East and Southeast Asia. Our study provides the first evidence for the subduction of supra-continental crustal materials up to 40-50 km depth during the collision between the Indochina and South China blocks.

UR - http://www.scopus.com/inward/record.url?scp=84979208577&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84979208577&partnerID=8YFLogxK

U2 - 10.2465/jmps.150727

DO - 10.2465/jmps.150727

M3 - Article

VL - 111

SP - 196

EP - 210

JO - Journal of Mineralogical and Petrological Sciences

JF - Journal of Mineralogical and Petrological Sciences

SN - 1345-6296

IS - 3

ER -