South Harris Anorthosite
Geological Conservation Review site | GCR #690 | Mineralogy | Mineralogy of Scotland
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Summary
New cuttings made in widening the Rodel-Finsbay road, together with a road metal quarry, here expose the anorthosite of the South Harris Igneous Complex. The anorthosite is an almost pure, light-grey, glassy feldspar rock with a slight greenish coloration due to epidotisation and replacement of feldspar by scapolite. Local increases in pyroxene and amphibole produce a banded rock with alternating purplish-grey and light greenish-white layers. Locally garnet is abundantly present and the pyroxene content increases markedly. Alternate layers of anorthosite and garnet pyroxenite (or metagabbro) result in a banded black and white rock. The garnets are up to 2cm diameter and invariably have dark kelyphite reaction rims. They are often slighly elongated in the folation. This banded rock is of considerable mineralogical and petrographic interest.
Related geosites
Overlaps with:
Pete Bowden
Oct. 1, 2024
Small road metal quarry adjacent to the C79. The highest peak is Roineabhal, (Roineval).
Pete Bowden
Oct. 1, 2024
Banding in anorthosite
Pete Bowden
Oct. 1, 2024
Large blocks of anorthosite at entrance to road metal quarry