M07. Garnet-Kyanite Gneiss - Slishwood
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Fact sheet

M07. Garnet-Kyanite Gneiss - Slishwood

This sample comes from the narrow northeast end of the Ox Mountains inlier, the same region as the metabasite garnet amphibolite P5218 in this collection. These rocks record a history of intense metamorphism within the high-pressure granulite facies, but the age of the protoliths and the age of metamorphism are uncertain. It is possible that the rocks are Dalradian, and that metamorphism occurred early in the Grampian orogenic event, but conventionally the extreme grade of metamorphism, and the clear signs of Grampian retrogression, has led to the view that the rocks are basement to the Dalradian Supergroup. Millimetre-sized garnet, kyanite and opaques are associated with ribbons of optically continuous quartz. K-feldspar, plagioclase and biotite are also present. The last three are mostly fine-grained and appear to have partially recrystallized after having been severely strained (the rock may once have been mylonite).

Rotation 1 - Nice kyanite with both cleavage traces sharp. Kyanite has straight extinction to the elongation. Rotation 2 - Strain shadowing and twinning in kyanite

54.204983, -8.446819
Ballygawley, near Slishwood, Northeast Ox Mountains, Co. Sligo, Ireland
About this collection

A group of iCRAG members (UCC, TCD, NUIG and UCD) in partnership with The Open University have created a new collection of Irish rocks and associated learning materials for the Virtual Microscope of Earth Sciences.

The project which is entitled 'The Geoscience e-Laboratory (GeoLab): Developing Digital Teaching and Learning Resources for the Virtual Microscope' seeks to develop open access teaching resources in the form of interactive exercises and assessment rubrics for the Virtual Microscope. Find out more about the project at the GeoLab website.

The Collection was created using funding from the Faculty of Engineering, Mathematics and Science at Trinity College, Dublin, and the National Forum Teaching and Learning Enhancement Fund. One sample (Merensky Reef) showcasing x-ray element maps in addition to the usual PPL/XPL/REF images was funded by Prof. Balz Kamber's MetalIntelligence EU training network grant.

Sample details

Rock-forming mineral
Accessory minerals
iron oxide
Category guide  
Category Guide
Refers to any word or phrase that appears in the individual rock names. Names are generally descriptive; they allow users to search for broad terms like ‘granite’ as well as more specific names such as ‘breccia’. However, the adjacent descriptions of the specimens captures a wider range of general words and phrases and is a more powerful search tool.
Refers to any word or phrase that appears anywhere in the descriptions of the specimens
Accessory minerals
Minerals that occur in very low abundance in a rock. They are usually not visible with the naked eye and contribute perhapssver, they often dominate the rare elements such as platinum group metals.
Rock-forming minerals
Minerals that make up the bulk of all rock samples and are also the ones used in rock classi?cation.
Selecting one or more period, for example 'Jurassic'.
A term used to group together related samples that are not already gathered into a single Collection. For instance, there is a ‘SW England granites’ theme that includes such rock types as granite, hydrothermal breccia, skarn and vein samples.
A general term used to label a rock sample. It is a useful way of grouping similar samples throughout a collection. Category names are often, but not exclusively, common rock names (e.g. granite, basalt, dolerite, gabbro, greisen, skarn, gneiss, amphibolite, limestone, sandstone).
The owner of the sample that appears in the collection. For example, NASA owns all the samples that appear in the Moon Rocks collection
We would like to thank the following for the use of this sample: