Journal of Petrology | Volume 44 | Number 5 | Pages 867-900 | 2003
© Oxford University Press 2003
Temperatures of Granulite-facies Metamorphism: Constraints from Experimental Phase Equilibria and Thermobarometry Corrected for Retrograde Exchange
1 DEPARTMENT OF GEOLOGY AND GEOPHYSICS, UNIVERSITY OF CALGARY, CALGARY, AB, T2N 1N4, CANADA
2 DEPARTMENT OF EARTH AND ATMOSPHERIC SCIENCES, UNIVERSITY OF ALBERTA, EDMONTON, AB, T6G 2E3, CANADA
3 DEPARTMENT OF GEOLOGY AND EARTH SYSTEM SCIENCE INTERDISCIPLINARY CENTRE, UNIVERSITY OF MARYLAND, COLLEGE PARK, MD 20742, USA
4 DEPARTMENT OF GEOLOGICAL SCIENCES, THE UNIVERSITY OF TEXAS AT AUSTIN, AUSTIN, TX 78701, USA
Telephone: 403-220-3263. Fax: 403-284-0074. E-mail: pattison{at}ucalgary.ca
This study assesses temperatures of formation of common granulites by combining experimental constraints on the P–T stability of granulite-facies mineral associations with a garnet–orthopyroxene (Grt–Opx) thermobarometry scheme based on Al-solubility in Opx, corrected for late Fe–Mg exchange. We applied this scheme to 414 granulites of mafic, intermediate and aluminous bulk compositions. Our findings suggest that granulites are much hotter than traditionally assumed and that the P–T conditions of the amphibolite–granulite transition portrayed in current petrology textbooks are significant underestimates by over 100°C. For aluminous and intermediate granulites, mean corrected temperatures based on our method are 890 ± 17 and 841 ± 11°C, respectively (uncertainties reported as 95% confidence limits on the mean), consistent with minimum temperatures for orthopyroxene production by fluid-absent partial melting in these bulk compositions. In contrast, mean temperatures based on Grt–Opx Fe–Mg exchange equilibria, using the same thermodynamic data, are 732 ± 22 and 723 ± 11°C, respectively, well below the minimum temperatures for Opx stability. For mafic granulites, the mean corrected temperature using our method is 816 ± 12°C, similar to the mean temperature of 793 ± 13°C from Fe–Mg exchange. Reasons for the differences between the mafic granulites and aluminous–intermediate granulites are unclear but may be due to the lower Al concentrations in Opx in the mafic rocks and possible deficiencies in the thermodynamic modelling of these low concentrations. We discuss a number of well-known granulite terrains in the context of our findings, including the Adirondacks, the Acadian granulites of New England, the incipient charnockites of southern India and Sri Lanka, and the Kerala Khondalite Belt. Our findings carry implications for thermotectonic models of granulite formation. A computer program to perform our thermobarometry calculations, RCLC, is available from the Journal of Petrology website at http://www.petrology.oupjournals.org or from the authors at http://www.geo.ucalgary.ca/~pattison/drm_pattison-rclc.htm.
KEY WORDS: granulite-facies metamorphism; thermobarometry; garnet; orthopyroxene
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  A. G. Tomkins and C. Grundy Upper Temperature Limits of Orogenic Gold Deposit Formation: Constraints from the Granulite-Hosted Griffin's Find Deposit, Yilgarn Craton Economic Geology, August 1, 2009; 104(5): 669 - 685. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Brown Metamorphic patterns in orogenic systems and the geological record Geological Society, London, Special Publications, January 1, 2009; 318(1): 37 - 74. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 H. Mirnejad and K. Bell GEOCHEMISTRY OF CRUSTAL XENOLITHS FROM THE HATCHER MESA LAMPROITE, WYOMING, USA: INSIGHTS INTO THE COMPOSITION OF THE DEEP CRUST AND UPPER MANTLE BENEATH THE WYOMING CRATON Can Mineral, June 1, 2008; 46(3): 583 - 596. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 P. ACQUAFREDDA, A. FORNELLI, G. PICCARRETA, and A. PASCAZIO Multi-stage dehydration-decompression in the metagabbros from the lower crustal rocks of the Serre (southern Calabria, Italy) Geological Magazine, May 1, 2008; 145(3): 397 - 411. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 C. Clark, M. Hand, D.E. Kelsey, and B. Goscombe Linking crustal reworking to terrane accretion Journal of the Geological Society, September 1, 2007; 164(5): 937 - 940. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 E. C. Hansen and D. E. Harlov Whole-rock, Phosphate, and Silicate Compositional Trends across an Amphibolite- to Granulite-facies Transition, Tamil Nadu, India J. Petrology, September 1, 2007; 48(9): 1641 - 1680. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
X. Liu, Y. Zhao, G. Zhao, P. Jian, and G. Xu Petrology and Geochronology of Granulites from the McKaskle Hills, Eastern Amery Ice Shelf, Antarctica, and Implications for the Evolution of the Prydz Belt J. Petrology, August 1, 2007; 48(8): 1443 - 1470. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. G. Tomkins, D. R. M. Pattison, and B. R. Frost On the Initiation of Metamorphic Sulfide Anatexis J. Petrology, March 1, 2007; 48(3): 511 - 535. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 W.G. Ernst, B.R. Hacker, and J.G. Liou Petrotectonics of ultrahigh-pressure crustal and upper-mantle rocks--Implications for Phanerozoic collisional orogens Geological Society of America Special Papers, January 1, 2007; 433(0): 27 - 49. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. A. Thomson A rare garnet-tourmaline-sillimanite-biotite-ilmenite-quartz assemblage from the granulite-facies region of south-central Massachusetts American Mineralogist, November 1, 2006; 91(11-12): 1730 - 1738. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
D. E. HARLOV, L. JOHANSSON, A. VAN DEN KERKHOF, and H.-J. FORSTER The Role of Advective Fluid Flow and Diffusion during Localized, Solid-State Dehydration: Sondrum Stenhuggeriet, Halmstad, SW Sweden J. Petrology, January 1, 2006; 47(1): 3 - 33. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. K. BHOWMIK, A. B. SARBADHIKARI, B. SPIERING, and M. M. RAITH Mesoproterozoic Reworking of Palaeoproterozoic Ultrahigh-temperature Granulites in the Central Indian Tectonic Zone and its Implications J. Petrology, June 1, 2005; 46(6): 1085 - 1119. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
B. R. Frost, S. M. Swapp, and R. W. Gregory PROLONGED EXISTENCE OF SULFIDE MELT IN THE BROKEN HILL OREBODY, NEW SOUTH WALES, AUSTRALIA Can Mineral, February 1, 2005; 43(1): 479 - 493. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
S. Prasad, A. Bhattacharya, M.M. Raith, and S. Bhadra The origin of orthopyroxene/biotite + plagioclase coronas from the Bolangir anorthosite complex (India), and implications for reconstructing P-T paths American Mineralogist, February 1, 2005; 90(2-3): 291 - 303. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
P. GONCALVES, C. NICOLLET, and J.-M. MONTEL Petrology and in situ U-Th-Pb Monazite Geochronology of Ultrahigh-Temperature Metamorphism from the Andriamena Mafic Unit, North-Central Madagascar. Significance of a Petrographical P-T Path in a Polymetamorphic Context J. Petrology, October 1, 2004; 45(10): 1923 - 1957. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
I. S. BUICK, G. STEVENS, and R. L. GIBSON The Role of Water Retention in the Anatexis of Metapelites in the Bushveld Complex Aureole, South Africa: an Experimental Study J. Petrology, September 1, 2004; 45(9): 1777 - 1797. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
T. JOHNSON and M. BROWN Quantitative Constraints on Metamorphism in the Variscides of Southern Brittany--a Complementary Pseudosection Approach J. Petrology, June 1, 2004; 45(6): 1237 - 1259. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Brown Hot orogens, tectonic switching, and creation of continental crust: Comment and Reply Geology, June 1, 2003; 31(6): e9 - e9. [Full Text] [PDF]
|
|
|
|
|
|
M. Brown Hot orogens, tectonic switching, and creation of continental crust: Comment and Reply: COMMENT Geology, January 1, 2003; 31(1): e9 - e9. [Full Text] [PDF]
|
|