M23. Garnet clinopyroxene plagioclase granulite
Collection:
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Fact sheet

M23. Garnet clinopyroxene plagioclase granulite

This garnet-clinopyroxene-plagioclase granulite comes from Slishwood in the northeastern end of the Ox Mountains inlier, a belt of extremely high-grade metasediments and metabasites whose age is uncertain. The rocks survive widespread Grampian epidote amphibolite facies retrograde alteration.  Conditions of the metamorphism were transitional between the granulite facies and the eclogite facies, and have been dubbed the high-pressure granulite facies.  The unusal intergrowth of clinopyroxene and plagioclase in the rock perhaps resulted from decompression of former sodium-aluminium-rich clinopyroxene (called omphacite) and, if so, then the rock was once eclogite.

Map
54.229008, -8.398223
Description:
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

Type
metamorphic
Rock-forming mineral
hornblende
amphibole
biotite
pyroxene
quartz
plagioclase
feldspar
Accessory minerals
rutile
iron oxide
Category guide  
Category Guide
Title
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.
Description
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.
Timescale
Selecting one or more period, for example 'Jurassic'.
Theme
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.
Category
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).
Owner
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: