Zircon U-Pb chronometry of the pressure and temperature history of granulites in the Musgrave Ranges, central Australia

Journal Article · Sun Sep 01 00:00:00 EDT 1991 · Journal of Geology; (United States)

DOI:https://doi.org/10.1086/629532· OSTI ID:5676034

Maboko, M A.H.; Williams, I S; Compston, W ^[1]

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1. Australian National Univ., Canberra (Australia)

Ion microprobe U-Pb measurements of zircon in the Musgrave Ranges of central Australia date the emplacement of a charnockite, which is cut by a shear zone containing a garnet-clinopyroxene assemblage, M2 (PT conditions {approximately} 11 kb and 720C), at {approximately} 1200 Ma. Veinlets of a post-M2 adamellite cut an M4 assemblage (PT conditions {approximately} 6 kb and 670C) contained in a metadolerite inclusion, suggesting that the adamellite was emplaced during or after M4. Igneous and metamorphic zircons in the adamellite, however, grew at about 1200 Ma, indicating that M2 and M4 were synchronous. At the level of precision of the data, the time interval between the growth of the two assemblages can not have been more than 20 Ma. The authors interpret the pressure, temperature and time (PTt) path obtained by combining the thermobarometric data, and zircon U-Pb ages in terms of magmatic heat input in a thickened crustal segment followed by rapid, possibly tectonically driven, uplift of the lower part of the thickened crust to a depth of 15-20 km.

• OSTI ID: 5676034
• Journal Information: Journal of Geology; (United States), Vol. 99:5; ISSN 0022-1376
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
AUSTRALIA
GEOLOGIC FORMATIONS
AGE ESTIMATION
ZIRCON
ISOTOPE RATIO
CONTINENTAL CRUST
GEOLOGIC HISTORY
ION MICROPROBE ANALYSIS
LEAD ISOTOPES
METAMORPHISM
RESERVOIR PRESSURE
RESERVOIR TEMPERATURE
TECTONICS
TIME DEPENDENCE
URANIUM ISOTOPES
ACTINIDE ISOTOPES
AUSTRALASIA
CHEMICAL ANALYSIS
DEVELOPED COUNTRIES
EARTH CRUST
ISOTOPES
MICROANALYSIS
MINERALS
NONDESTRUCTIVE ANALYSIS
SILICATE MINERALS
580000* - Geosciences