An Cleireach
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Condition (NatureScot)
| Unit | Feature | Condition | Area (ha) | Assessed |
|---|---|---|---|---|
| F1 | Tertiary Igneous | Favourable | — | 2007-02-12 |
Geology & landscape
Geological Feature: Igneous Intrusion · Geological Period: Paleogene · Rock Type: Basalt, Gabbro
Landscape processes: Volcanic / Igneous
Description
AN CLEIREACH An Cleireach Site of Special Scientific Interest (SSSI) is located in the hills between Dunvegan and Portree in the north of the Isle of Skye near Balmeanach. The site encompasses a Tertiary igneous intrusion, which is of significant petrogenetic importance in revealing the characteristics of the dyke-like bodies and sills containing gabbroic-anorthosite and gabbro which intrude the plateau lavas of north-west Skye. An Cleireach SSSI contains an excellent example of a coarse gabbroic-anorthosite sheet. This provides textural evidence that the sheet became choked with early-formed plagioclase megacrysts which had crystallized from a low-alkali, high-calcium tholeiitic basalt magma. The geochemistry of the intrusion thus confirms the existence of a low-alkali, high-calcium tholeiitic magma towards the end of Palaeogene volcanism in northern Skye and furthers our understanding of the igneous activity of the area at that time.