9655252
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU9655252
| Property | Value |
|---|---|
| id | 9655252 |
| igsn | 10.60494/dqtn-nm53 |
| sample_id | MAN-1 |
| eno | 912547 |
| sampling_feature_name | 779-63 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| stratigraphic_unit | Mannum Granite |
| geological_province | Delamerian Orogen |
| sample_remark | Foden et al. (2006): The undeformed Mannum pluton (Turner and Foden 1996) is a high-level, potassic, rapakivi, (A-type) syenogranite. The intrusion has limited outcrop, but total magnetic intensity imagery shows that it clearly cross-cuts the Reedy Creek pluton and is part of an extensive series of post-tectonic A-type granites and lavas with associated mafic dikes and enclaves that extend to the southeast into Victoria (Turner et al. 1992). The age of this pluton provides a minimum age of the termination of the Delamerian deformation in the southeastern Mount Lofty ranges. The Mannum granite hosts swarms of enclaves that result from mingling of a mafic magma with the host granite. As demonstrated by Turner and Foden (1996), the mafic enclaves and granite show initial Sr-isotopic equilibrium and are probably different fractionation and mingling stages of the same parent magma. Based on a recalculation of the whole-rock Rb-Sr isotope data published by Turner and Foden (1996) using ISOPLOT (Ludwig 1999), the eight-point model 1 Rb-Sr isochron is 482.3 +/- 4.5 Ma. In southeast South Australia (Padthaway Ridge), these post-Delamerian plutons are associated at the same structural level with contemporary felsic volcanic rocks (Turner et al. 1992; Foden et al. 1990). This observation and evidence for shallow intrusion of the Mannum granite provided by the fine grain size of the first-stage intrusion and miarolitic cavities indicate that the upper amphibolite facies Delamerian metamorphic complexes (Alias et al. 2002) were nearly exhumed before being intruded by these late granite complexes. A large titanite crystal that grew within the mafic enclaves in the Mannum granite was dated and gave an age of 449 +/- 5 Ma (two-point titanite-feldspar 238U/204Pb-206Pb/204Pb isochron). This is similar to ages obtained for a magmatic-hydrothermal event in the Mount Painter Inlier (Elburg et al. 2003), located farther north in the Adelaide Fold Belt. |
| earth_materials | Y |
| structural_measurements | None |
| inorganic_geochemistry | None |
| organic_geochemistry | None |
| geochronology | None |
| isotope_groups | Y |
| 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 | 139.3528524 |
| gda94_latitude | -34.8929681 |
| sample_originator | Foden, J.D. |
| date_acquired | 2000-01-01 00:00:00 |
| Links |
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