Banniskirk Quarry

Also within

Caithness County

Condition (NatureScot)

Geology & landscape

Mining / Industrial: Quarry · Geological Period: Devonian · Rock Type: Sandstone

Description

BANNISKIRK QUARRY Banniskirk Quarry SSSI is situated 3km north of the village of Spittal, 15km southeast of Thurso, Caithness. The site has been designated because it has a layer of rock known as calcareous laminite that contains fossil fish. The fossil fish bed has been exposed here as a result of quarrying to extract flagstones. This is the first site in Scotland where fossil fish were found in Old Red Sandstone (in 1826). The fish bed at Banniskirk was deposited about 380 million years ago during the Middle Devonian geological time period. The area that is now Caithness was a shallow lake (known as ‘Lake Orcadie’) at that time. When fish died, their remains settled on the bottom of the lake. The fish remains were gradually covered by sediment and compressed, eventually becoming fossilised. Banniskirk Quarry contains fish beds that are slightly younger than those exposed in the nearby quarries at Spittal and Achanarras. Fossils from at least three groups of fish have been found at Banniskirk Quarry: Dicksteus threiplandi, Acanthodii spp. and Dipterus valenciennesi. Banniskirk is the type locality (first site in the world where a fossil was discovered and described) for Dipterus valenciennesi and is the most important site for this species. The site also contains very well preserved Dicksteus threiplandi. The full range of fish that used to live in Lake Orcadie is poorly known and this site has considerable potential for future research to extend the understanding of these fish and the environment in which they lived.