| P number: | P521266 |
|---|---|
| Caption: | Rock specimen of hornblende feldspar quartz gneiss. Beinn Ceannabeinne [?], Durness, Sutherland, Scotland. |
| Description: | The rock is a strongly banded (or 'striped') medium-grained crystalline rock, comprising pale-coloured (pinkish or flesh colour) bands composed of alkali feldspar, alternating with dark-coloured bands of grey-green hornblende with minor feldspar. British Geological Survey Petrology Collection sample number EMC56. The presence of hornblende in a metamorphic rock indicates metamorphism at the middle grades of thermal (contact) metamorphism, or of low-pressure regional metamorphism known as the Buchan-type. It indicates temperatures of formation in the range 400-650 degrees Celsius. The sample is from the Lewisian (Precambrian) complex, a mixed assemblage of igneous rocks and high grade metamorphic rocks. It is unconformably overlain by the Torridonian sedimentary rocks. |
| Date taken: | Sun Dec 01 00:00:00 GMT 2002 |
| Photographer: | McTaggart, F.I. |
| Associate: | T.S. Bain |
| Copyright statement: | NERC |
| Additional information: | EMC56 |
| Orientation: | Portrait |
| Size: | 287.11 KB; 775 x 1000 pixels; 66 x 85 mm (print at 300 DPI); 205 x 265 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Best of BGS Images/ Geological structures |
Loading...
Loading...
Reviews
There is currently no feedback