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|Title:||Summary of Results. NTGS LA-ICP-MS U-Pb geochronology project: Detrital zircon U-Pb geochronology of the Parke Siltstone, HENBURY 1:250 000 mapsheet, Amadeus Basin|
|Report ID:||NTGS Record 2019-013|
|Geological Province:||Amadeus Basin|
|Map100:||Palm Valley 5449|
|Abstract:||This Record presents laser ablation inductively-coupled plasma mass spectrometer (LA-ICP-MS) U-Pb isotope data for detrital zircons from a sample of the Devonian Parke Siltstone collected during 2017 in the HENBURY area of the central Amadeus Basin. The aim of this geochronological study was to constrain the maximum depositional age of the Devonian Parke Siltstone, as well as to provide additional results to the extensive Neoproterozoic Devonian detrital zircon provenance dataset of the central Amadeus Basin.|
Detrital zircons from the Parke Siltstone have major age peaks at ca 1.6 Ga, 1.2 Ga, and 1 Ga, suggesting that the dominant sources of zircons were likely to be the Warumpi Province to the north (1.6 Ga) and the Musgrave Province to the south (1.2 and 1.0 Ga). The youngest single concordant U-Pb zircon date obtained is 564 ± 7 Ma (2s), which is >100 My older than the depositional age of the Parke Siltstone interpreted from biostratigraphy.
In the context of previous detrital zircon results from HENBURY, the age spectrum of the Parke Siltstone falls within an anomalous group that includes the Ordovician Horn Valley Siltstone and Stokes Siltstone. Results from these three rock units are atypical because, unlike other post-mid Cambrian strata of the Amadeus Basin, they do not include a prominent zircon age peak of ca 700-500 Ma that seems to reflect an exotic zircon source. These three units are dominated by fine grained lithofacies, in contrast to the other units that comprise the majority of the dataset. The absence of the ca 700-500 Ma peak in these three units therefore suggests a relationship between sediment sources and patterns of transgression and regression in the Amadeus Basin.
|Publisher:||Northern Territory Geological Survey|
|Document Type:||NTGS Record|
|Access Constraint:||Creative Commons Attribution 4.0 International (CC BY 4.0). Please observe and retain any copyright or related notices that accompany this material and give attribution to: Northern Territory of Australia (Northern Territory Geological Survey).|
|Appears in Collections:||Reports, Records, Books|
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