An integrated microtextural and chemical approach to zircon geochronology; refining the Archaean history of the Napier Complex, East Antarctica

Saved in:
Online Access: Get full text
doi: 10.1007/s00410-004-0635-6
Authors:Kelly, Nigel M.; Harley, Simon L.
Author Affiliations:Primary:
University of Edinburgh, Grant Institute of Earth Sciences, Edinburgh, United Kingdom
Volume Title:Contributions to Mineralogy and Petrology
Source:Contributions to Mineralogy and Petrology, 149(1), p.57-84. Publisher: Springer International, Heidelberg-New York, International. ISSN: 0010-7999
Publication Date:2005
Note:In English. 99 refs.; illus., incl. 6 tables, sketch map
Summary:Integrated textural and chemical characterisation of zircon is used to refine the U-Pb geochronology of the Archaean, ultra-high temperature Napier Complex, east Antarctica. Scanning electron microscope characterisation of zircon and the rare earth element compositions of zircon, garnet and orthopyroxene are integrated to place zircon growth in an assemblage context, thereby providing tighter constraints on the timing of magmatic and metamorphic events. Data indicate that magmatism occurred in the central and northern Napier Complex at ca. 2,990 Ma. A regional, relatively low-pressure metamorphic event occurred at ca. 2,850-2,840 Ma. Mineral REE data from garnet-bearing orthogneiss indicate that ca. 2,490-2,485 Ma U-Pb zircon ages provide an absolute minimum age for the ultrahigh temperature (UHT) foliation preserved in this rock. (mod. journ. abst.)
Sections:Age determination; Petrology
Subjects:Absolute age; Archean; Charnockite; Chemical composition; Complexes; Crystal form; Dates; Deformation; Fabric; Felsic composition; Folds; Geochemistry; Gneisses; Granites; High-grade metamorphism; Igneous rocks; Ion probe data; Isotope ratios; Isotopes; Lead; Mafic composition; Magmatism; Mass spectra; Metals; Metamorphic rocks; Metamorphism; Mineral assemblages; Mineral composition; Napier Complex; Nesosilicates; Orthosilicates; Pb-206/Pb-204; Petrography; Plutonic rocks; Precambrian; Pressure; Radioactive isotopes; Rare earths; Rb/Sr; SEM data; SHRIMP data; Silicates; Spectra; Stable isotopes; Structural analysis; Tectonics; Textures; Trace elements; U/Pb; Ultrahigh pressure; Zircon; Zircon group; Antarctica; East Antarctica; Enderby Land; Dallwitz Nunatak; Gage Ridge; Proclamation Island
Coordinates:S680000 S663000 E0530000 E0480000
Abstract Numbers:05M/1375
Record ID:2005036173
Copyright Information:GeoRef, Copyright 2019 American Geosciences Institute.
Tags: Add Tag
No Tags, Be the first to tag this record!