Olivine gabbro - Huntly
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Fact sheet

Olivine gabbro - Huntly

This coarse-grained olivine gabbro sample comes from one of several large basic intrusions in NE Scotland that were intruded during the Grampian orogeny. The sample was collected from the Bin quarry, Huntly, Aberdeenshire, where the intrusion displays overturned cumulate layering with compositions varying from gabbro to troctolite. The variation in composition of the gabbro at this locality reflects processes such as fractional crystallisation and contamination by the surrounding Dalradian metasediments. The rock is a plagioclase-olivine-augite cumulate gabbro and this example is about 489 million years old.

In thin section the large olivine grains exhibit black alteration minerals, such as hematite, along internal cracks, and dominantly green-coloured chlorite alteration at the grain margins. The pyroxene is also cracked but exhibits well-defined cleavage with some grains showing two cleavages at the characteristic 90 degree separation. Plagioclase feldspar crystals have an aligned cumulate texture and exhibit strong lamellar twinning.

Additional images
  • gabbro - width 2 cm
57.475362, -2.838708
Bin quarry, near Huntly, Scotland
About this collection

The United Kingdom Virtual Microscope (UKVM) collection consists of igneous, sedimentary and metamorphic rocks from around the UK.

It is intended as a teaching resource, helping to tell the story of the common rock types and how they form, and reflecting the history of the UK at the margins of the continent of Europe. The collection is a series of teaching sets, for example igneous rocks from the North Atlantic Igneous Province and SW England; high-temperature metamorphic rocks from Scotland and low-temperature metamorphic rocks from Wales; and sedimentary rocks, including English limestones and sandstones.

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: