| P number: | P524275 |
|---|---|
| Caption: | Photomicrograph of feldspathic lava. Light: PPL, Magnification x 10. 2750 feet 266 degrees from farmhouse, Laws, Angus. |
| Description: | The image shows a photomicrograph of a feldspathic lava consisting of large plagioclase feldspar phenocrysts enclosing a mixture of smaller plagioclase laths and small darker crystals or pyroxene, chlorite and opaque oxide. British Geological Survey Petrology Collection sample number S 48879. Light: PPL, Magnification x 10. Light: PPL, Magnification x 10. Many fine-grained igneous rocks contain feldspar crystals in the form of elongate laths. Sometimes these can be aligned if the rock has begun to crystallize as it was still flowing. It is possible to work out the direction of lava flow from these aligned crystals. A widespread calc-alkaline igneous province extended throughout Scotland and Northern Ireland during the Devonian. Volcanic rocks constitute the major part of the Lower Devonian successions forming prominent uplands such as the Sidlaw, Ochil, Pentland and Carrick Hills. Most fall within the ages 411 to 407 Ma. Most volcanic successions consist of basaltic and andesitic lava flows with intercalated volcaniclastic sediments ranging from siltstones to conglomerates. Lava flows were usually impersistent, interdigitating concordant sheets 3 to 15 m. thick. |
| Date taken: | Wed Jan 01 00:00:00 GMT 2003 |
| Photographer: | Hyslop, E.K. |
| Copyright statement: | NERC |
| X longitude/easting: | 348500 |
| Y latitude/northing: | 735000 |
| Coordinate reference system, ESPG code: | 27700 (OSGB 1936 / British National Grid) |
| Orientation: | Landscape |
| Size: | 304.69 KB; 1000 x 667 pixels; 85 x 56 mm (print at 300 DPI); 265 x 176 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
Loading...
Loading...
Reviews
There is currently no feedback