2678684
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU2678684
| Property | Value |
|---|---|
| id | 2678684 |
| igsn | 10273/AU2678684 |
| sample_id | BB5676 |
| eno | 625704 |
| sampling_feature_name | BB5676 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| stratigraphic_unit | Kurbayia Metamorphic Complex |
| geological_province | Kalkadoon-Leichhardt Domain |
| sample_remark | On this low rocky ridge, ~50 m S of the track, BB5676 was collected from a ~1 m thick dyke comprising equigranular medium-grained muscovite-biotite granite, which crosscuts the migmatitic gneiss hosting mafic boudins/inclusions/"relicts" (of which BB5675 is representative). The muscovite-biotite granite forms numerous dykes ranging from ~3 cm to 1 m in thickness, and some of the thicker dykes are pegmatitic in part, with coarse muscovite common. The granitic dykes cut across the foliation in the gneiss, and the average of 11 magnetic susceptibility readings is 6.03 x 10-3 SI units. In thin section, the rock consists mainly of medium-grained relict feldspar grains (up to ~1.5 mm) in a matrix (~0.3 mm) consisting mainly of recrystallised quartz. Modal proportions are ~35% K-feldspar, ~30% plagioclase, ~32% quartz, ~8% micas, with K-feldspar being more abundant than plagioclase. K-feldspar is mainly fresh, and cross-hatched twinning is common, as are fine exsolution lamellae of sodic plagioclase. Plagioclase grains are generally extensively sericitised, with minor fine muscovite in some grains. Biotite is almost completely recrystallised, with sparse scattered relict grains, and appears to be slightly more abundant than muscovite overall. However, sparse relict muscovite grains are more common than relict biotite. Relict muscovite is characterised by highly undulose extinction, and commonly has curved cleavage planes. The matrix consists almost entirely of recrystallised quartz (no relict quartz grains were observed), together with minor recrystallised biotite and muscovite/sericite, which tend to be concentrated in thin stringers or lenticles. |
| earth_materials | Y |
| structural_measurements | None |
| inorganic_geochemistry | Y |
| organic_geochemistry | None |
| geochronology | Y |
| isotope_groups | Y |
| 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 | 139.6426005 |
| gda94_latitude | -20.9241196 |
| sample_originator | Bultitude, R.J. |
| date_acquired | None |
| Links |
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