| P number: | P521363 |
|---|---|
| Caption: | Rock specimen of biotite porphyry. East face of Screel, near Hanging Craig, 4.5 miles south of Castle Douglas, Kirkcudbrightshire, Scotland. |
| Description: | The rock consists of a brownish-grey, fine-grained groundmass containing large crystals of pale-coloured feldspar and less common black biotite. British Geological Survey Petrology Collection sample number EMC3724. The Dalbeattie (or Criffel) granite in south-west Scotland is surrounded by many small intrusions of porphyrite which consist of a devitrified glassy groundmass in which are embedded abundant large phenocrysts. Many of these rocks can be classified as hornblende biotite andesites. The largest concentration of Caledonian minor intrusions in the Kirkudbright-Dalbeattie district is the Black Stockarton Moor sub-volcanic complex. Four stages of emplacement were a. A mass of intersecting lamprophyre and microdiorite dykes, granodiorite sheets, small granodiorite stocks and breccia pipes. b. Bengain Complex of pluton emplacement. c. A regional suite of north-west trending lamphrophyric and porphyritic dykes. d. The Cairnsmore of Fleet Pluton. The intrusions are Devonian in age. |
| Date taken: | Sun Dec 01 00:00:00 GMT 2002 |
| Photographer: | McTaggart, F.I. |
| Associate: | T.S. Bain |
| Copyright statement: | NERC |
| Additional information: | EMC3724 |
| Orientation: | Landscape |
| Size: | 291.74 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 |
Loading...
Loading...
Reviews
There is currently no feedback