9655751
Persistent Identifier: https://pid.geoscience.gov.au/sample/AU9655751
| Property | Value |
|---|---|
| id | 9655751 |
| igsn | 10.60494/94b9-0380 |
| sample_id | 95-35 |
| 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: "Leucosome 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 leucosome sample was taken from a vein ~0.1 m thick (as distinct from a localised partial melt patch) and consisting mainly of coarse (>5 mm) quartz, cordierite and feldspar. Cordierite, in contrast to that in the melanosome, is not poikilitic and, with the exception of scattered sillimanite needles, is relatively inclusion free. Ragged andalusite grains are up to 2 mm diameter. Rare biotite flakes up to 1 mm are associated with masses of fibrolitic sillimanite and contain abundant pleochroic haloes around radioactive inclusions. New zircon growth is ubiquitous in the migmatite samples. Much less zircon was recovered from the leucosome. As in the melanosome the crystals are fine-grained (40-100 um), but they are consistently more prismatic, with aspect ratios ranging from 2 to 5, commonly with large {211} crystal faces. Cathodoluminescence imaging shows that, in contrast to the melanosome zircon, the crystals are dominated by new growth. Pyramidal overgrowths commonly 50 um, and in some cases up to 100 um, thick surround zircon cores that are smaller on average than those in the melanosome. It is not unusual for the overgrowth to exceed 70% of the volume of the grain. Even so, the overgrowths on the prism faces can be very thin, and in some cases barely cover the irregular surface of the core. The overgrowths are consistently weakly luminescent, and any zoning present is indistinct, broad and simply euhedral. Like the accompanying monazite, the new zircon is rich in acicular inclusions that are probably sillimanite." |
| 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 |
|