Limestones of Scotland — image resources: Difference between revisions

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== Introduction =  
== Introduction ==
'''Chapter 6 Petrographical descriptions of Scottish limestones'''
'''Chapter 6 Petrographical descriptions of Scottish limestones'''


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=== Argyll ===
=== 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: [https://webapps.bgs.ac.uk/data/britrocks/britrocks.cfc?method=viewSamples&sampleId=374442 S31697]
Geoscenic: [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=120600 P552546] Mag: 40 Light: PPL
Geoscenic: [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=120602 P552547] Mag: 40 Light: XPL
Geoscenic: [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=120605 P552548] Mag: 40 Light: PPL
Geoscenic: [https://geoscenic.bgs.ac.uk/asset-bank/action/viewAsset?id=120608 P552549] Mag: 40 Light: XPL

Revision as of 13:01, 7 August 2021

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