NS3678 : Former cornstone workings on Carman Muir
taken 16 years ago, near to Renton, West Dunbartonshire, Scotland
Cornstone (a kind of limestone) was quarried from various locations on Carman Muir, to be burned for lime, but the industry was centred on this particular knoll: a ruined lime-kiln can be seen on its northern side, and there are extensive spoil mounds and signs of quarrying nearby. See Link for an annotated satellite view centred on this area. See Link for details of former quarrying on Carman Muir as a whole.
See Link (in a Geograph article) for further information, and Link for an annotated satellite view on which various features of geological interest (as well as traces of associated industries and other antiquities) are marked, as described below.
The topography of the parts of Carman Muir to the south of Cardross Road is determined to a large extent by cornstone deposits, which outcrop in places. Cornstone is an impure granular limestone, a fossil soil. Old quarry pits (probably worked before the nineteenth century) and possible test pits can be seen along the lines of these deposits; they are indicated by light blue marker pins on the annotated satellite view, and the cornstone outcrops are marked by orange pins.
This area, lying to the south of Cardross Road, exemplifies what the British Geological Survey refers to as the Kinnesswood Formation (see Link at the BGS website for more information); this formation contains cornstone deposits.
Beside and to the north of Cardross Road are outcrops of sandstone rather than cornstone. The sandstone is best seen along a line of outcrops and pits beside the road (these are indicated by reddish marker pins on the annotated satellite view). Another prominent example lies at the ENE end of that line: a large disused red sandstone quarry, the old Fairy Knowe Quarry (later known as Carman Quarry) – Link – at NS36967900. This area beside and to the north of the road exemplifies the Stockiemuir Sandstone Formation (see Link at the BGS website for further details).
Both north and south of the road, the strata in this area generally dip at an angle of from 10° to 20° from the horizontal, descending towards the SSE; the Stockiemuir Sandstone Formation that is exposed beside and to the north of the road underlies the cornstone-containing Kinnesswood Formation to the south of the road.
The annotated satellite view also includes markers for various antiquities in the area:
● Ancient cairns: Link
● Circular enclosure: Link (originally reported as a hut circle)
● Carman (house): Link
● Carman (enclosure): Link
● Carman (field system): Link