| P number: | P553001 |
|---|---|
| Caption: | Limestone-and dolomite. Old quarry, west bank of Allt Folais, 690 yards north of Letterewe House. Ross & Cromarty. |
| Description: | Thinly and irregularly flaggy limestone with a reticulation of thin veins of calcite. The slide shows a rock in which angular grains of calcite about 0.05 to 0.3 mm across are scattered like grains of grit in a very fine matrix of carbonate of grain size 0.01 mm. This is cut by thin veins containing calcite, quartz and barytes. The latter two minerals occur also in small aggregates throughout the rock. Phlogopite is present in flakes up to 0.5 mm long. The residue from solution in 1 : 3 HCl, cold, shows barytes, quartz, phlogopite and dolomite in that order of abundance. A sericitic clay aggregate is also present, Some curious small spheroidal growths of calcite in the rock seem to be of the same age as the formation of phlogopite. Limestone with quartz, barytes, phlogopite and dolomite, fine-grained, pseudo-gritty mortar-structure, sheared. S 35265, Whitish micro-nodular dolomite, with phlogopite coating divisional planes; effervesces slightly in cold dilute HCl. The rock is a crushed dolomite with a gritty appearance in thin section owing to the distribution of larger irregular grains of carbonate (up to 1.0 mm across) in a matrix which is of variable but very fine grain. Phlogopite, muscovite and tremolite are abundantly present and the latter occurs as incomplete prisms or relict shreds in fibrous carbonate. Tourmaline (elbaite) is an abundant accessory, forming stout, fractured prisms up to 0.2 mm long. Colourless in thin sections, it shows: O, faint green, E faint pink in separated grains; omega = 1.639. Tests in crush show dolomite as the main constituent, but calcite is abundant. Calcareous dolomite with micas and tremolite; fine-grained, pseudo-gritty mortar-structure, crushed. SL0259. Britrocks S35265(a). Magnification x40. Light XPL. |
| 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: | 407.33 KB; 1000 x 750 pixels; 85 x 64 mm (print at 300 DPI); 265 x 198 mm (screen at 96 DPI); |
| Average Rating: | Not yet rated |
| Categories: | Unsorted Images |
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