Uploaded on:
2009-03-18 12:50:32.0
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P number: P553064
Caption: Marble. Roadside 430 yards east-north-east of Ledbeg. Sutherland.
Description: A massive, structureless, compact, white marble, with faint yellow patternless markings. Composed of an aggregate of shapeless interlocking grains of calcite, 0.05 - 0.15 mm in size. These are generally traversed by very close set cleavage and twinning planes. In places the rock shows a mottling due to angularly patchy distribution of clear and turbid calcite. The clear patches are composed of the small grains and the turbid patches seem to be relics of large crystals in which almost submicroscopic striations (due to cleavage or twinning or both) have been produced. The striations are subparallel throughout the patch and are interrupted where new small grains with broader twin lamellae have crystallized. The orientation of the lamellae in such grains is diverse. In places narrow lines of shear are shown by granulation and parallel orientation of calcite grains and by a lining of thin serpentine flakes. Pseudomorphs of olivine in serpentine are sporadic in the rock as individual crystals or clusters. Phlogopite also is present in small flakes and aggregates, the calcite associated with which is coarser in grain than elsewhere in the rock. The rock is a marble triturated by stress. Limestone, serpentinous, varigrained, sheared. SL0271. Britrocks S35796. Magnification x40. Light PPL.
Date taken: Wed Jan 21 00:00:00 GMT 2004
Photographer: Sutherland, A.
Copyright statement: NERC
Additional information: Description from: Limestones of Scotland: chemical analyses and petrography. Edinburgh : HMSO, 1956.
Orientation: Landscape
Size: 347.77 KB; 1000 x 750 pixels; 85 x 64 mm (print at 300 DPI); 265 x 198 mm (screen at 96 DPI);
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