| P number: | P528000 |
|---|---|
| Caption: | Photomicrograph of cornstone. Light: PPL. Magnification: x2.5. Quarry 400 yards west by north of Selms, 1.25 miles south of East Calder, Midlothian, Scotland. |
| Description: | A nodular rock composed of larger buff nodules which effervesce freely in cold dilute hydrochloric acid and greenish non-effervescent nodules, in a fine breccia-like base containing much recrystallized or infiltrated calcite. This specimen is Upper Old Red Sandstone (Devonian) in age. BGS sample number SL 180. British Geological Survey Petrology Collection sample number S 34901. Photomicrograph details: Light: PPL, Magnification: x2.5. The thin section image shows the greenish nodules and these are composed of silty micaceous argillite or mudstone, marginally replaced by prisms of calcite growing in from the infilling calcite. The latter is composed of coarse grains which show growth zones and in places two periods of growth separated by a period of silica deposition. Some of the vein-like infillings contain also a central deposit of chalcedonic quartz. The rock is a mud-rich very fine-grained limestone containing clear nodules of coarser-grained calcite and occasional calcite veins. |
| Date taken: | Sun Jun 25 00:00:00 GMT 1905 |
| Photographer: | Unknown |
| Copyright statement: | Unknown |
| Orientation: | Landscape |
| Size: | 352.50 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: | Unsorted Images |
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