Limestones of Scotland — image resources
Introduction
Chapter 6 Petrographical descriptions of Scottish limestones
Lewisian
Argyll
GS1 (p. 17) Coccolite marble. Quarry 92 yd E. 31° S. of Balephetrish, Tiree. 1" sheet 42; 6" Argyll. 64 N.E. (Anal. C.O. Harvey).
An elongated mass of marble, 200 ft by 50 ft, enclosed on three sides by black hornblende-augite-gneiss; fourth side passes under drift.
(S31697). Pink marble speckled with green clots. 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.
Limestone with calcsilicates, micrograined, pseudoporphyroblastic, grano-schistose, sheared.
Britrocks: S31697
Geoscenic: P552546 Mag: 40 Light: PPL
Geoscenic: P552547 Mag: 40 Light: XPL
Geoscenic: P552548 Mag: 40 Light: PPL
Geoscenic: P552549 Mag: 40 Light: XPL