2771361
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU2771361
| Property | Value |
|---|---|
| id | 2771361 |
| igsn | 10273/AU2771361 |
| sample_id | ERIVKFB0550.01 |
| eno | 628630 |
| sampling_feature_name | ERIVKFB0550 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| earth_materials | Y |
| stratigraphic_unit | Koetong Granite |
| geological_province | Central NSW - Omeo Province |
| sample_remark | Weathered and clay-altered, medium- to coarse-grained biotite granite with K-feldspar porphyroclasts up to 5 cm. The granite has undergone significant shear-related deformation (Bull, 2017), with rotational fabrics indicating sinistral shear sense, and rodded quartz defining mineral stretching lineations. The granite hosts lenses of fine-grained biotite schist, interpreted as metapelitic enclaves. In thin section, the granite features 0.5-1.0 cm feldspar ex-phenocrysts within a recrystallised quartz-rich fabric defined by biotite and sillimanite. Myrmekite is developed in strain shadows on feldspar porphyroclasts, and some alkali feldspars comprise flame perthite, suggesting exsolution recrystallisation. Primary biotite is deformed and rotated, and is mantled by sillimanite and later biotite. Some small crystals are rutilated. Quartz is non-strained, which might indicate that high temperatures outlasted shear-related deformation, or that the rock was overprinted by high-temperature contact metamorphism during emplacement of the adjacent 407.4+/-1.9Ma Mullengandra Monzodiorite (ERIVKFB0327.01). Bull (2017) assigned this sheared porphyritic granite to the Koetong Granite, which occupies a NW-trending fault along strike from the sinistral Tallangatta Creek Fault Zone in Victoria. Chappell et al. (1991) classified the Koetong Granite as a Silurian felsic unfractionated S-type, and assigned it to the Koetong Suite of the Koetong Supersuite. Anderson et al. (1996) quoted a U-Pb zircon date of 419 +/- 6 Ma for the 'Koetong Adamellite' in Victoria, but the distribution of the Koetong Granite and the neighbouring S-type felsic fractionated Granya Granite is uncertain (Campbell,2020). Ickert and Williams (2011) dated the Granya Granite at 435.8+/-4.5Ma in Victoria, and Bodorkos et al.(2015) obtained a U-Pb SHRIMP zircon date of 428.2+/-2.7Ma near Wymah in NSW, in an area Chappell et al.(1991) mapped as Koetong Granite, but Chappell (1999) designated Granya Granite. |
| structural_measurements | None |
| inorganic_geochemistry | Y |
| organic_geochemistry | None |
| geochronology | Y |
| isotope_groups | None |
| hydrochemistry | None |
| rock_properties | None |
| mineralogy | None |
| thin_sections | None |
| repository_samples | Y |
| mineral_deposit_samples | None |
| mineral_deposit_waste_samples | None |
| linked_files | None |
| other_geological_data | None |
| project_name | None |
| gda94_longitude | 147.121245 |
| gda94_latitude | -35.885498 |
| sample_originator | Geological Survey of New South Wales (GSNSW) |
| date_acquired | 2018-05-08 00:00:00 |
| Links |
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