Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa

Yusuke Seto; Shugo Ohi; Norimasa Shimobayashi; Masao Kitamura; Akira Miyake; Yoshikuni Hiroi; Geoffrey H. Grantham

doi:10.2138/am.2006.2063

Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa

Yusuke Seto, Shugo Ohi, Norimasa Shimobayashi, Masao Kitamura, Akira Miyake, Yoshikuni Hiroi, Geoffrey H. Grantham

Research output: Contribution to journal › Article › peer-review

7 Citations (Scopus)

Abstract

Chemical and crystallographic properties of clinopyroxene exsolution in wollastonite are described from metamorphosed calc-silicate granulite, Namaqualand, South Africa. The wollastonite is Ca_1.96Fe_0.01Al_0.01 Si_2.01O₆ belonging to space group P2₁/a (2M polytype) and the clinopyroxene is Ca_0.99 Mg_0.75-0.80 Fe_0.17-0.21 Na_0.02 Al_0.03 Si_1.99-2.00 O₆ belonging to C2/c. An electron backscattered diffraction investigation suggests that the clinopyroxene lamellae elongated along [111] lie on (120) and (100) of the wollastonite-2M, and [11̄0] of both lamellae are parallel to [001] of the wollastonite-2M. The formation of the exsolution probably results from the relatively high peak metamorphic temperature (800-860°C) of the Namaqualand granulite and its slow cooling rate.

Original language	English
Pages (from-to)	446-450
Number of pages	5
Journal	American Mineralogist
Volume	91
Issue number	2-3
DOIs	https://doi.org/10.2138/am.2006.2063
Publication status	Published - 2006
Externally published	Yes

Keywords

Clinopyroxene
EBSD
Exsolution
TEM
Wollastonite

ASJC Scopus subject areas

Geophysics
Geochemistry and Petrology

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10.2138/am.2006.2063

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title = "Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa",

abstract = "Chemical and crystallographic properties of clinopyroxene exsolution in wollastonite are described from metamorphosed calc-silicate granulite, Namaqualand, South Africa. The wollastonite is Ca1.96Fe0.01Al0.01 Si2.01O6 belonging to space group P21/a (2M polytype) and the clinopyroxene is Ca0.99 Mg0.75-0.80 Fe0.17-0.21 Na0.02 Al0.03 Si1.99-2.00 O6 belonging to C2/c. An electron backscattered diffraction investigation suggests that the clinopyroxene lamellae elongated along [111] lie on (120) and (100) of the wollastonite-2M, and [1{\=1}0] of both lamellae are parallel to [001] of the wollastonite-2M. The formation of the exsolution probably results from the relatively high peak metamorphic temperature (800-860°C) of the Namaqualand granulite and its slow cooling rate.",

keywords = "Clinopyroxene, EBSD, Exsolution, TEM, Wollastonite",

author = "Yusuke Seto and Shugo Ohi and Norimasa Shimobayashi and Masao Kitamura and Akira Miyake and Yoshikuni Hiroi and Grantham, {Geoffrey H.}",

year = "2006",

doi = "10.2138/am.2006.2063",

language = "English",

volume = "91",

pages = "446--450",

journal = "American Mineralogist",

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TY - JOUR

T1 - Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa

AU - Seto, Yusuke

AU - Ohi, Shugo

AU - Shimobayashi, Norimasa

AU - Kitamura, Masao

AU - Miyake, Akira

AU - Hiroi, Yoshikuni

AU - Grantham, Geoffrey H.

PY - 2006

Y1 - 2006

N2 - Chemical and crystallographic properties of clinopyroxene exsolution in wollastonite are described from metamorphosed calc-silicate granulite, Namaqualand, South Africa. The wollastonite is Ca1.96Fe0.01Al0.01 Si2.01O6 belonging to space group P21/a (2M polytype) and the clinopyroxene is Ca0.99 Mg0.75-0.80 Fe0.17-0.21 Na0.02 Al0.03 Si1.99-2.00 O6 belonging to C2/c. An electron backscattered diffraction investigation suggests that the clinopyroxene lamellae elongated along [111] lie on (120) and (100) of the wollastonite-2M, and [11̄0] of both lamellae are parallel to [001] of the wollastonite-2M. The formation of the exsolution probably results from the relatively high peak metamorphic temperature (800-860°C) of the Namaqualand granulite and its slow cooling rate.

AB - Chemical and crystallographic properties of clinopyroxene exsolution in wollastonite are described from metamorphosed calc-silicate granulite, Namaqualand, South Africa. The wollastonite is Ca1.96Fe0.01Al0.01 Si2.01O6 belonging to space group P21/a (2M polytype) and the clinopyroxene is Ca0.99 Mg0.75-0.80 Fe0.17-0.21 Na0.02 Al0.03 Si1.99-2.00 O6 belonging to C2/c. An electron backscattered diffraction investigation suggests that the clinopyroxene lamellae elongated along [111] lie on (120) and (100) of the wollastonite-2M, and [11̄0] of both lamellae are parallel to [001] of the wollastonite-2M. The formation of the exsolution probably results from the relatively high peak metamorphic temperature (800-860°C) of the Namaqualand granulite and its slow cooling rate.

KW - Clinopyroxene

KW - EBSD

KW - Exsolution

KW - TEM

KW - Wollastonite

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U2 - 10.2138/am.2006.2063

DO - 10.2138/am.2006.2063

M3 - Article

AN - SCOPUS:33745933335

SN - 0003-004X

VL - 91

SP - 446

EP - 450

JO - American Mineralogist

JF - American Mineralogist

IS - 2-3

ER -

Clinopyroxene exsolution in wollastonite from Namaqualand granulite, South Africa

Abstract

Keywords

ASJC Scopus subject areas

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