P number: | P527982 |
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Caption: | Photomicrograph of Stinchar Limestone. Light: PPL. Magnification: x2.5. Tormitchell Quarry, Pinmore, Ayrshire, Scotland. |
Description: | Pale buff, or cream-coloured, compact limestone with semicrystalline lustre. This specimen is Ordovician in age. BGS sample number SL 154. British Geological Survey Petrology Collection sample number S 34656. Photomicrograph details: Light: PPL, Magnification: x2.5. The rock is composed of a matrix of clear calcite, of 0.05-0.3 mm grain size, containing ooliths and numerous fairly well sorted calcareous pebbles, comprising subrounded fragments and knobby spheroids from 0.3-1.5 mm in size, perhaps of algal origin, subangular to rounded pieces of very fine-grained limestone containing ooliths and crinoid fragments but sometimes uniformly structureless, and rare crinoid ossicles. The rock is traversed by many thin calcite-filled cracks which show tensional rupture without lateral displacements. A few quartz grains are present in the matrix and in the semi-opaque limestone. The rock has oolitic and pseudo-oolitic structures. Oval ooliths have radial and concentric internal structure; pseudo-ooliths are less regularly rounded and do not possess regular internal structure. |
Date taken: | Sun Jun 25 00:00:00 GMT 1905 |
Photographer: | Unknown |
Copyright statement: | Unknown |
Orientation: | Landscape |
Size: | 342.02 KB; 1000 x 663 pixels; 85 x 56 mm (print at 300 DPI); 265 x 175 mm (screen at 96 DPI); |
Average Rating: | Not yet rated |
Categories: | Best of BGS Images/ Rocks and minerals under the microscope |
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