Thermal gradients in the Sri Lankan granulite terrane: A garnet-biotite thermometric approach

K. Sajeev, Yasuhito Osanai

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

Thermal zoning of the Highland Complex, Sri Lanka has been delineated using the Fe2+-Mg distribution coefficient between garnet and biotite from garnet-biotite gneiss samples collected with wide geographical distribution. In order to minimize the potential for retrograde Fe-Mg exchange and maximize the potential for retaining peak equilibrium KD (garnet-biotite) and temperature, garnet and biotite included within feldspar and quartz without other mineral inclusions have been selected. The calculated results indicate four distinct temperature contours with KD values varying from 1.84 to 6.38 and temperature varying from 996 to 591 °C. From the present results, it is possible to divide the Highland Complex into two major metamorphic zones: a high-temperature area in the central region and a low-temperature area in the south-western and north-eastern region. In conjunction with the metamorphic pressure variations estimated from the granulites of the Highland Complex in previous studies, it is shown that the high- and low-temperature areas are complemented by a high-pressure region towards the eastern side and a low-pressure region towards the western side of this complex. This thermal dome is interpreted to be an artifact of the different crustal levels exhumed following Pan-African metamorphism.

Original languageEnglish
Pages (from-to)383-397
Number of pages15
JournalJournal of Metamorphic Geology
Volume23
Issue number5
DOIs
Publication statusPublished - Jun 2005

Fingerprint

Garnets
granulite
Thermal gradients
biotite
terrane
garnet
Temperature
temperature
geographical distribution
gneiss
zoning
dome
artifact
low pressure
feldspar
metamorphism
Geographical distribution
Zoning
Quartz
quartz

All Science Journal Classification (ASJC) codes

  • Geology

Cite this

Thermal gradients in the Sri Lankan granulite terrane : A garnet-biotite thermometric approach. / Sajeev, K.; Osanai, Yasuhito.

In: Journal of Metamorphic Geology, Vol. 23, No. 5, 06.2005, p. 383-397.

Research output: Contribution to journalArticle

@article{2d31dd17b7754503a6cecf51f94a422b,
title = "Thermal gradients in the Sri Lankan granulite terrane: A garnet-biotite thermometric approach",
abstract = "Thermal zoning of the Highland Complex, Sri Lanka has been delineated using the Fe2+-Mg distribution coefficient between garnet and biotite from garnet-biotite gneiss samples collected with wide geographical distribution. In order to minimize the potential for retrograde Fe-Mg exchange and maximize the potential for retaining peak equilibrium KD (garnet-biotite) and temperature, garnet and biotite included within feldspar and quartz without other mineral inclusions have been selected. The calculated results indicate four distinct temperature contours with KD values varying from 1.84 to 6.38 and temperature varying from 996 to 591 °C. From the present results, it is possible to divide the Highland Complex into two major metamorphic zones: a high-temperature area in the central region and a low-temperature area in the south-western and north-eastern region. In conjunction with the metamorphic pressure variations estimated from the granulites of the Highland Complex in previous studies, it is shown that the high- and low-temperature areas are complemented by a high-pressure region towards the eastern side and a low-pressure region towards the western side of this complex. This thermal dome is interpreted to be an artifact of the different crustal levels exhumed following Pan-African metamorphism.",
author = "K. Sajeev and Yasuhito Osanai",
year = "2005",
month = "6",
doi = "10.1111/j.1525-1314.2005.00582.x",
language = "English",
volume = "23",
pages = "383--397",
journal = "Journal of Metamorphic Geology",
issn = "0263-4929",
publisher = "Wiley-Blackwell",
number = "5",

}

TY - JOUR

T1 - Thermal gradients in the Sri Lankan granulite terrane

T2 - A garnet-biotite thermometric approach

AU - Sajeev, K.

AU - Osanai, Yasuhito

PY - 2005/6

Y1 - 2005/6

N2 - Thermal zoning of the Highland Complex, Sri Lanka has been delineated using the Fe2+-Mg distribution coefficient between garnet and biotite from garnet-biotite gneiss samples collected with wide geographical distribution. In order to minimize the potential for retrograde Fe-Mg exchange and maximize the potential for retaining peak equilibrium KD (garnet-biotite) and temperature, garnet and biotite included within feldspar and quartz without other mineral inclusions have been selected. The calculated results indicate four distinct temperature contours with KD values varying from 1.84 to 6.38 and temperature varying from 996 to 591 °C. From the present results, it is possible to divide the Highland Complex into two major metamorphic zones: a high-temperature area in the central region and a low-temperature area in the south-western and north-eastern region. In conjunction with the metamorphic pressure variations estimated from the granulites of the Highland Complex in previous studies, it is shown that the high- and low-temperature areas are complemented by a high-pressure region towards the eastern side and a low-pressure region towards the western side of this complex. This thermal dome is interpreted to be an artifact of the different crustal levels exhumed following Pan-African metamorphism.

AB - Thermal zoning of the Highland Complex, Sri Lanka has been delineated using the Fe2+-Mg distribution coefficient between garnet and biotite from garnet-biotite gneiss samples collected with wide geographical distribution. In order to minimize the potential for retrograde Fe-Mg exchange and maximize the potential for retaining peak equilibrium KD (garnet-biotite) and temperature, garnet and biotite included within feldspar and quartz without other mineral inclusions have been selected. The calculated results indicate four distinct temperature contours with KD values varying from 1.84 to 6.38 and temperature varying from 996 to 591 °C. From the present results, it is possible to divide the Highland Complex into two major metamorphic zones: a high-temperature area in the central region and a low-temperature area in the south-western and north-eastern region. In conjunction with the metamorphic pressure variations estimated from the granulites of the Highland Complex in previous studies, it is shown that the high- and low-temperature areas are complemented by a high-pressure region towards the eastern side and a low-pressure region towards the western side of this complex. This thermal dome is interpreted to be an artifact of the different crustal levels exhumed following Pan-African metamorphism.

UR - http://www.scopus.com/inward/record.url?scp=22144446434&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=22144446434&partnerID=8YFLogxK

U2 - 10.1111/j.1525-1314.2005.00582.x

DO - 10.1111/j.1525-1314.2005.00582.x

M3 - Article

AN - SCOPUS:22144446434

VL - 23

SP - 383

EP - 397

JO - Journal of Metamorphic Geology

JF - Journal of Metamorphic Geology

SN - 0263-4929

IS - 5

ER -