| P number: | P521428 |
|---|---|
| Caption: | Rock specimen of eucrite. On rising ground 600 yards north-east of Achosnich School, Kilchoan, Ardnamurchan, Argyllshire, Scotland. |
| Description: | The sample is a distinctive grey coarse-grained igneous rock comprising black crystals of pyroxene within a groundmass of intergrown laths of grey plagioclase feldspar. British Geological Survey Petrology Collection sample number EMC4095. A eucrite is a very basic intrusive igneous rock composed mainly of calcic plagioclase feldspar and clinopyroxene, with smaller amounts of olivine. It is a variety of gabbro. The name was first used in 1864, and is derived from the Greek word for 'easily discerned'. The Ardnamurchan peninsula consists of a major Tertiary igneous centre intruded into the Moine Schists and thin overlying Mesozoic rocks. The centre is one of a number including Skye, Mull, Rum and Arran. Development of a centre comprises four main events. 1. The eruption of large quantities of basic lavas, they are about 100 m. thick in Ardnamurchan. 2. The creation of central vents, vent agglomerates and tuffs 3. Emplacement of arcuate and annular plutonic rocks often concentrically around a centre (or several) with cone sheets and ring intrusions. Ardnamurchan has three main centres. 4. The emplacement of large numbers of dykes. The eucrites are part of centre 3. |
| Date taken: | 01/12/2002 |
| Photographer: | McTaggart, F.I. |
| Associate: | T.S. Bain |
| Copyright statement: | NERC |
| Additional information: | EMC4095 |
| Orientation: | Landscape |
| Size: | 242.80 KB; 1000 x 775 pixels; 85 x 66 mm (print at 300 DPI); 265 x 205 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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