2771352
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU2771352
| Property | Value |
|---|---|
| id | 2771352 |
| igsn | 10273/AU2771352 |
| sample_id | ERIVMAE1269.01 |
| eno | 628623 |
| sampling_feature_name | ERIVMAE1269 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| earth_materials | Y |
| stratigraphic_unit | Ellerslie Granodiorite |
| geological_province | Central NSW - Omeo Province |
| sample_remark | Coarse-grained, pale pinkish-orange, foliated granite containing 5-7% ferromagnesian minerals. Weathered surfaces emphasise a secondary foliation, defined by elongate quartz-rich aggregates, dipping steeply ESE. In thin section, it comprises K-feldspar (47%), quartz (40%), plagioclase (10%), and biotite (3%), with accessory zircon and apatite. Large primary quartz crystals are dynamically recrystallised to a patchwork of irregular grains with extensive subgrain development. Alkali feldspar crystals are up to 7 mm, many with simple twins. Most feature fine perthite lamellae +/- coarser-grained albite 'vein' perthite, and some have albite additions at the crystal tips in a classic 'Manhattan' texture. Microcline twinning is common in the K-feldspar component. Stubby plagioclase crystals are 1-4 mm and feature subtly warped/kinked polysynthetic twins, tapered deformation twins, and some albitic additions. Greenish-brown biotite is recrystallised into irregular aggregates extensively altered to chlorite +/- epidote. High-strain domains between feldspar phenocrysts feature extensive recrystallisation of quartz, and incipient recrystallisation of adjacent K-feldspar margins. These microstructures are consistent with deformation at low- to medium-temperature conditions (400-500C; Passchier and Trouw, 2005). A minor granitic phase of the Ellerslie Granodiorite with a distinct high K-equivalent response (red to pinkish-red tones), represented by ERIVMAE1269.01, lies along the E margin of the pluton. Chappell et al. (1991) classified the Ellerslie Granodiorite as a mafic, unfractionated, I-type. New observations and measurements by Eastlake (2020) support this interpretation: minor tonalitic phases contain primary hornblende, and new geochemical analyses indicate a weakly peraluminous I-type affinity. |
| 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 | 147.996188 |
| gda94_latitude | -35.298788 |
| sample_originator | Geological Survey of New South Wales (GSNSW) |
| date_acquired | 2018-05-08 00:00:00 |
| Links |
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