The small peralkaline microgranite intrusion that forms the island of Ailsa Craig in the Firth of Clyde represents the southern-most intrusion of the British Palaeogene Volcanic Province (BPVP) within Scotland. The granitic rocks of Ailsa Craig, famous for their use in making curling stones, are thought to be the result of fractionation from a mantle-derived basic magma with no crustal contamination. The rocks of Ailsa Craig also contain the comparatively rare alkaline ferromagnesian minerals riebeckitic arfvedsonite, hedenbergite-acmite and aenigmatite. These factors make the Ailsa Craig intrusion unique in the BPVP. The distinctive ‘spotty’ appearance of the Ailsa Craig granites, which is invaluable as a tracer in establishing Pleistocene glacial transport, results from the close association of ferromagnesian minerals with drusy cavities. This suggests that, unlike the more common dark minerals, they formed late in the cooling and crystallisation history of the magma.

Ailsa Craig was selected as part of the Geological Conservation Review network covering the rocks of the British Palaeogene Volcanic Province, which for historic reasons, is known as the ‘Tertiary Igneous’ GCR block. Site descriptions for GCR sites of the Tertiary Igneous block are contained in the 4th published GCR volume (Emeleus and Gyopari, 1992). Ailsa Craig GCR site was, however, omitted for reasons unknown. A full GCR site description for Ailsa Craig is, therefore, provided in this paper in order to complete the published description of the Tertiary Igneous GCR block.

在克莱德峡湾形成Ailsa Craig岛的小碱性高花岗岩微侵入岩，代表了苏格兰英国不列颠古纪火山省（BPVP）最南端的侵入岩。阿伊萨·克雷格（Ailsa Craig）的花岗岩岩以生产冰壶石而闻名，被认为是源自地幔的基本岩浆的分级分离的结果，而没有地壳污染。艾尔萨·克雷格（Ailsa Craig）的岩石中还含有相对稀少的碱性铁锰矿矿物，雷贝克岩，钠铁辉石和堇青石。这些因素使Ailsa Craig入侵在BPVP中独树一帜。艾尔玛·克雷格（Ailsa Craig）花岗岩独特的“斑点”外观，可作为建立更新世冰川运输的示踪剂，其价值源于铁磁矿物与弥散性腔的紧密联系。

艾尔莎·克雷格（Ailsa Craig）被选为地质保护评论网络的一部分，该网络覆盖了英国古近纪火山省的岩石，由于历史原因，该省被称为“第三纪火成岩” GCR区块。第三纪火成岩块的GCR站点的站点描述包含在第四版GCR卷中（Emeleus和Gyopari，1992）。但是，由于未知原因，省略了Ailsa Craig GCR网站。因此，本文提供了Ailsa Craig的完整GCR站点描述，以完成对第三纪火成岩GCR块的公开描述。