P number: | P527923 |
---|---|
Caption: | Photomicrograph of coccolite marble. Light: XPL. Magnification: x2.5. Quarry 92 yards east 31 degrees south of Balephetrish, Tiree, Argyllshire, Scotland |
Description: | An elongated mass of pink marble speckled with green clots, 200 feet by 50 feet, enclosed on three sides by black hornblende-augite-gneiss; the fourth side passes under drift. This specimen is Lewisian (Precambrian) in age. BGS Sample Number GS 1. British Geological Survey Petrology Collection sample number S 31697. The section shows an aggregation of very fine-grained calcite in which numerous lens-shaped relics of larger grains are arranged parallel in shear-schistosity. Rounded crystals of pale green pyroxene, micacized scapolite, a negative alkali-feldspar and large grains of calcite form xenolith-like aggregates. Sphene, apatite and limonitic aggregate are accessory constituents which occur both as isolated grains in the calcite matrix and in association with the pyroxene clusters. |
Date taken: | Sun Jun 25 00:00:00 GMT 1905 |
Photographer: | Unknown |
Copyright statement: | Unknown |
Orientation: | Landscape |
Size: | 395.89 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 |
Reviews
There is currently no feedback