1840026
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU1840026
| Property | Value |
|---|---|
| id | 1840026 |
| igsn | 10273/AU1840026 |
| sample_id | RJB3206 |
| eno | 407110 |
| sampling_feature_name | RJB3206 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| earth_materials | Y |
| stratigraphic_unit | Botumburra Range Monzogranite |
| geological_province | New England Orogen |
| sample_remark | This Botumburra Range Monzogranite sample consists of pale grey, fine- to medium-grained, slightly porphyritic biotite-hornblende granodiorite, comprising ~50% plagioclase, ~20% quartz, ~15% alkali feldspar, ~8% hornblende, and ~7% biotite. Most grains in the granodiorite at the sample site range from ~0.5 mm to ~3 mm (average ~1.5 mm). Plagioclase phenocrysts are well-formed laths up to ~1 cm long (abundant). Some larger plagioclase grains contain small inclusions of hornblende and relatively coarse zircon (scarce). Late-crystallised alkali feldspar (microperthite) commonly fills interstices as anhedral grains up to ~3 mm across - minor component. These grains contain very fine exsolution lamellae of sodic plagioclase. Hornblende grains are subhedral-euhedral, up to ~2 mm long, and pleochroic from pale brownish green to pale yellow. They contain tiny inclusions of an unidentified mineral(s), some surrounded by dark pleochroic haloes, as well as scarce larger zircon euhedra and opaque oxide granules. Simple twins are common and a few grains display multiple twinning. Biotite forms mainly discrete blocky grains up to ~3 mm long that are pleochroic from dark reddish brown to pale yellowish brown (light tan). Larger grains, some displaying undulose extinction, contain small inclusions of opaque oxide and apatite? as well as coarse zircon. Rare titanite (as anhedral grains ~0.5 mm across) and accessory zircon, as relatively coarse grains in the groundmass and small inclusions in biotite, hornblende (and lesser plagioclase), were also detected. The granodiorite is overall fresh. Most plagioclase show slight sericitisation, and a few have been extensively sericitised, particularly relatively calcic cores. The sericite is accompanied locally by epidote. Biotite grains are unaltered or slightly altered, some replaced by chlorite, generally accompanied by secondary titanite. Hornblende are generally unaltered, a few contain small, irregular grains of secondary titanite. |
| 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 | 152.3022852 |
| gda94_latitude | -30.5879235 |
| sample_originator | Bultitude, R.J. |
| date_acquired | None |
| Links |
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