9655750
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU9655750
| Property | Value |
|---|---|
| id | 9655750 |
| igsn | 10.60494/xr90-6z45 |
| sample_id | 95-34 |
| eno | 917391 |
| sampling_feature_name | 95-34/35 |
| sampling_feature_type | field site |
| sample_type | outcrop specimen |
| sampling_method | outcrop sampling |
| material_class | rock |
| stratigraphic_unit | Cooma Metamorphic Complex |
| geological_province | Lachlan Orogen |
| sample_remark | Williams 2001 paraphrased: "Melanosome migmatite. The migmatite consists of disrupted, but in places broadly continuous, bands of metapsammite in a matrix of coarser grained metapelite containing widespread evidence (veins and localised coarse-grained quartzo-feldspathic segregations) of smallscale partial melting. The melanosome sample (medium-grained, biotite rich metapsammite) consists of quartz, biotite, cordierite, and minor andalusite, muscovite, K-feldspar, plagioclase and fibrolitic sillimanite. Fresh cordierite forms poikilitic crystals up to several millimetres in diameter that enclose fine biotite, multiple small rounded inclusions of quartz and feldspar, and a dusting of tiny radioactive grains (zircon and ?monazite), each surrounded by a pronounced pleochroic halo. New zircon growth is ubiquitous in the migmatite samples. Despite many crystals having a rounded shape reminiscent of detrital grains, very few of the many fine (40-100 um) zircons recovered from the melanosome show remnant surface abrasion. Most grains are multifaceted, many are sharply euhedral. Secondary electron images show the grains to be entirely surrounded by new zircon, either as a thin film that barely covers the roughness of the abraded surface, or as a thicker layer forming multiple small crystal faces. Cathodoluminescence images reveal that the thickness of the new layer ranges from a few micrometres where the pyramids of the crystals have begun to develop to a micrometre or so on the prism faces. In all cases, no matter how irregular the shape of the kernel of detrital zircon, the pyramids of the crystal have developed first and grown fastest. The new layer is uniformly weakly luminescent and unzoned." |
| earth_materials | Y |
| structural_measurements | None |
| inorganic_geochemistry | None |
| organic_geochemistry | None |
| geochronology | None |
| isotope_groups | None |
| 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 | None |
| gda94_longitude | 149.081336 |
| gda94_latitude | -36.24035 |
| sample_originator | Williams, S. |
| date_acquired | 3000-01-01 00:00:00 |
| Links |
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