| P number: | P519724 |
|---|---|
| Caption: | Polished slab of Laxfordian gneiss, Sutherland, Scotland |
| Description: | The sample is a detail of a cut and polished sample of Laxfordian gneiss. It is dominated by layers of intergrown pale-coloured quartz and feldspar with darker black biotite mica. The smaller reddish flecks are grains of iron oxide. The specimen is of Precambrian, Lewisian age. British Geological Survey Petrology Collection sample number EMC 5686. Although not widely used as a building stone, the decorative properties of Lewisian gneiss make it a very attractive material for cladding. The greater part of the Lewisian rocks in Scotland were formed in the late Archaean and are the oldest rocks in Scotland at c. 2900-2700 Ma. They formed when the earth's crust was relatively hot and mobile and in consquence the rocks were subjected to repeated deformation and high-grade metamorphism. The zone of Laxford granite sheets separates the younger event of the Laxfordian Lewisian of mostly migmatites with pegmatites to the north and the much older less reworked Scourian granulites to the south. |
| Date taken: | Wed Jan 01 00:00:00 GMT 2003 |
| Photographer: | Bain, T.S. |
| Copyright statement: | NERC |
| Orientation: | Landscape |
| Size: | 334.02 KB; 1000 x 886 pixels; 85 x 75 mm (print at 300 DPI); 265 x 234 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
Loading...
Loading...
Reviews
There is currently no feedback