“depositional environment”

This outing was based on Paul Kabrna’s “Carboniferous Geology, Bowland Fells to Pendle Hill”, Excursion 2, Slaidburn Anticline.

“The aim of this excursion is to demonstrate a range of depositional environments from platform/ramp limestones (Tournaisian stage) to basinal hemipelagic mudstones (Visean stage).” Kabrna, p140.

There are nine localities on this trip and no attempt was made to visit all of them. Many require permission from the farmer to access the sites, which was sought and obtained.

On a beautiful morning we walked out of the village noting the Birkett Sandstone of the War Memorial and the Thornton Limestone by the Old Bridge where we left the road. Crossing the fields we followed the R. Hodder upstream, and then its tributary Barn Gill. Thornton Limestone, oldest of the four members of the Clitheroe Limestone Formation, was also seen at Hammerton Crag and Hammerton Ford. Bellman Limestone, top of that Formation, was also seen at the Crag.

Phynis Mudstone and Whitemore Limestone (an 80 m thick turbidite limestone) were seen in Barn Gill before we retraced our steps to make our way to Rain Gill where the quarry is the type locality for Rain Gill Limestone. “The outcrop consists of of 5 m of mainly fine- to coarse-grained dark grey wackestones and packstones.” Kabrna, p.144.

We the made our way back to the village where we obtained refreshments before taking to cars to visit the Pendleside Sandstone at Anna Land (or Lane) End. From there, home.

Rain Gill Limestone in Rain Gill Quarry, Slaidburn


Image and text by J.Hutchinson