Whiteadder Water - an excursion

By D.C.Greig. From Scottish Borders geology: an excursion guide edited by A.D. McAdam, E.N.K. Clarkson, P. Stone. Edinburgh : Scottish Academic Press (for Edinburgh Geological Society), 1972.

Author: A.D. McAdam O.S. 1:50000 Sheet 74 Kelso

BGS 1:50 000 Geological Survey of Scotland map. 34 Eyemouth Drift

BGS 1:50 000 Geological Survey of Scotland map. 34 Eyemouth Bedrock

Introduction

The Cementstone Group, the lowest series in the Carboniferous of Berwickshire, is exposed in many of the sections cut in the valley sides of the Whiteadder Water. It is difficult to relate these sections one to another, because of the lack of distinctive horizons, the absence of progressive upward lithological change and the variable structure (Greig 1988, pp 45-49)

1. East Blanerne: Cementstone Facies

One of several good cliff sections cutting cementstone facies in the Whiteadder Water, lies 2 km WNW of Chirnside by the B6355 road where there is limited roadside parking (NT 845 570). Access can be gained from the west end of the cliff and the section examined by scrambling along the base. The cliff is some 5 to 10 m high and is surmounted by a few metres of red sand and gravel deposits resting on boulder clay. The strata dip generally to the south-east exposing some 30 m of section. The beds are dominantly grey in colour with some green and reddish beds. The strata are mainly composed of grey mudstones and silty mudstones, generally poorly-bedded and blocky, with beds of siltstone and sandstone, and ribs and bands of cementstone. Faulting affects the south-east end of the section. The bivalves Modiolus latus? And Curvirimula, Spiororbis, ostracods and fish fragments have been reported.

2. Willie's Hole: Cementstone Facies, Plants

Return to Chirnside and continue south through Allanton on the B6437 road. Take the first left past Broomdykes, left again at the next T-junction and straight on at the next junction. A good track goes down to the riverside where there is parking by the footbridge and ford. Walk west along the track across the alluvial plain for 500 m to a cutting beside the low riverside cliff, waterfall and pool known as Willie's Hole (NT 878 547). A 1.5 m pale brown fine-grained sandstone, dipping at 12 degrees to the south, forms a low waterfall across the river. Above the sandstone are exposed 5 m of grey mudstones and silty mudstones with pale brown-grey nodular cementstone ribs less than 10 cm in thickness. Six metres of similar beds occur below the sandstone but with thicker cementstone bands up to 30 cm, one making a low weir across the river. Well-preserved plants are found at this locality, including Alcicornopteris and Archaeocalamites. Also recorded are the bivalves Lithophaga and Modiolus, together with `Estheria', ostracodes, an early scorpion Eoscorpius?, rare fish fragments and eurypterid fragments. The shrimp Tealliocaris occurs in a silty bed towards the top of the section. Cater et al (1989) on the general palaeontology (Wood and Rolfe), the sedimentology (Anderton), the plants (Scott and Meyer-Berthaud), the miospores (Clayton), certain arthropods (Waterston, Briggs and Clarkson, Almond), the ostracods (Pollard), various fish (Forey and Young, Gardiner, Andrews) and the palaeoecology (Clarkson). Although protected the site can be visited and some of the 30 m section in grey cementstone facies can still be examined.

References

At all times follow: The Scottish Access Codeand Code of conduct for geological field work