9655254
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU9655254
| Property | Value |
|---|---|
| id | 9655254 |
| igsn | 10.60494/n80r-dk28 |
| sample_id | HRM-mtot |
| eno | 912549 |
| sampling_feature_name | HRM |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| stratigraphic_unit | Kanmantoo Group |
| geological_province | Delamerian Orogen |
| sample_remark | Foden et al. (2020): This sample was taken from the Harveys Return locality, at the NW corner of Kangaroo Island, where deformed amphibolite-facies metasedimentary rocks of the Kanmantoo Group have been transported towards the Gawler Craton margin in the hanging wall of the major Kangaroo island thrust system, part of the regional D1 structural event (Flottmann et al., 1998). The inter-bedded sandstone-mudstone 1-20 cm sedimentary layering of the Kanmantoo Group has been recrystallised to prominent black and white pelite-psamite layers with prominent chlorite-absent biotite and muscovite growth, implying a metamorphic temperature of ~550C (e.g. Tinkham et al., 2001), and defining the axial planar foliation of the N-vergent recumbent folds. Three muscovite aliquots were separated for 40Ar/39Ar analysis at Curtin University and yielded a weighted plateau age of 502.4 +/- 4 Ma. As the metamorphic temperature of muscovite growth in this sample is probably ~200C higher than the 40Ar/39Ar closure T for muscovite (~350C; Harrison et al., 2009), this is likely to be a cooling age. Even if a quite rapid cooling rate (~20C/Ma) was assumed, this implies that the age of tectonically imposed muscovite growth may have been ~10 Ma older than the cooling age, suggesting the age of thrusting to be ~512 Ma (regional D1). |
| earth_materials | Y |
| structural_measurements | None |
| inorganic_geochemistry | None |
| organic_geochemistry | None |
| geochronology | None |
| isotope_groups | None |
| hydrochemistry | None |
| rock_properties | None |
| mineralogy | None |
| thin_sections | None |
| repository_samples | None |
| mineral_deposit_samples | None |
| mineral_deposit_waste_samples | None |
| linked_files | None |
| other_geological_data | None |
| project_name | EFTF - Isotopic Atlas of Australia |
| gda94_longitude | 136.638276 |
| gda94_latitude | -35.748031 |
| sample_originator | Foden, J.D. |
| date_acquired | 2000-01-01 00:00:00 |
| Links |
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