The crag structure on southern slopes of Queen’s Park

Abstract

It will be convenient in the subsequent remarks to accept Boue’s designation of the sweep of Salisbury Crags as extending from their commencement opposite Holyrood to where the Queen’s Drive curves round towards Dunsappie, just above the gatekeeper’s lodge at Duddingston Loch. Of course many crags are included in this area. But it is only within the scope of this paper to show that on the south flanks of Salisbury Crags, in the open rock models on the large scale, in the quarries from the ‶Hause″ to the ‶Cat’s-Nick,″ may be demonstrated a mode of structure of the greenstone distinct from that of a coulee flow from a crater. And, though analogy is not identity, this will raise as yet a moot point that Samson’s Ribs are in anyway part of the exposed neck of the old volcano, or that its connected crags on either side are flows from it. Indeed, this study may induce us to advert to Lord Greenock’s opinion, that the igneous rocks of Edinburgh were not projected as modern lavas from a vertical crater, but injected laterally across the bedding of the aqueous strata. We do not maintain this theory, but it is valuable as a record of rock phenomena which the fashionable one does not account for. Boue long ago characterised the notion of Arthur Seat being a cone of volcanic aggregation, the hill itself being the analogue of Vesuvius, and Salisbury Crags of the more ancient Somma, as a notion only feasible at first