The provenance of Archean clastic metasediments in the Narryer Gneiss Complex, western Australia: Trace element geochemistry, Nd isotopes, and U-Pb ages for detrital zircons

Journal Article · Mon Jul 01 00:00:00 EDT 1991 · Geochimica et Cosmochimica Acta; (United States)

DOI:https://doi.org/10.1016/0016-7037(91)90033-2· OSTI ID:5904262

Maas, R ^[1]; McCulloch, M T ^[2]

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1. Australian National Univ., Canberra (Australia) Curtin Univ., Perth (Australia)
2. Curtin Univ., Perth (Australia)

Clastic metasedimentary rocks of mid-Archean age from the Mt. Narryer and Jack Hills metasedimentary belts have REE patterns resembling those of mid- to late-Archean pelitic-quartzitic cratonic sequences elsewhere, and post-Archean continental rocks in general. Detrital zircons in the metasediments range in age from ca. 3,000 to 3,700 Ma. This indicates a provenance from mature cratonic sources controlled by K-rich granitic rocks. Additional minor sediment sources were identified as older, mainly chemical sedimentary sequences, ultramafic rocks, and felsic rocks characterized by low HREE contents, perhaps of tonalitic affinity. Differences between sedimentary REE patterns and those in the surrounding 3.73-3.0 Ga orthogneiss terrain, and between detrital zircon ages and the age distribution in the gneisses, suggest that the present association of the metasedimentary belts with the orthogneiss terrain is of tectonic origin. The occurrence of detrital zircons with U-Pb ages > 4 Ga in certain quartzites and conglomerates of the Jack Hills and Mt. Narryer metasedimentary sequences indicates a further, most likely granitic, source. {epsilon}{sub Nd}(T{sub Dep}) values in Jack Hills metasediments vary widely (+5 to {minus}12) but have a smaller range in the Mt. Narryer belt ({minus}5 to {minus}9). The lowest {epsilon}{sub Nd} values of both sequences are interpreted to reflect the presence of detritus derived from 4.1-4.2 Ga old LREE-enriched continental crust in proportions considerably larger ({ge} 10%) than estimated previously from the abundance of pre-4 Ga detrital zircons ({approx}3%). This would imply the former existence of significant volumes of pre-4 Ga continental crust in the provenance of the Mt. Narryer and Jack Hills metasediments.

• OSTI ID: 5904262
• Journal Information: Geochimica et Cosmochimica Acta; (United States), Vol. 55:7; ISSN 0016-7037
• Country of Publication: United States
• Language: English

Related Subjects

58 GEOSCIENCES
QUARTZITES
GEOCHEMISTRY
PETROGENESIS
ZIRCON
ISOTOPE DATING
CONTINENTAL CRUST
GEOLOGIC HISTORY
GNEISSES
LEAD ISOTOPES
NEODYMIUM
ORIGIN
PRECAMBRIAN ERA
RARE EARTHS
SEDIMENTS
TECTONICS
URANIUM ISOTOPES
WESTERN AUSTRALIA
ACTINIDE ISOTOPES
AGE ESTIMATION
AUSTRALASIA
AUSTRALIA
CHEMISTRY
DEVELOPED COUNTRIES
EARTH CRUST
ELEMENTS
GEOLOGIC AGES
ISOTOPES
METALS
METAMORPHIC ROCKS
MINERALS
ROCKS
SILICATE MINERALS
580000* - Geosciences