Lectures and Excursions


The group holds meetings and talks at Hanson’s cement works near Clitheroe.

The dates and times of which will be posted on this page.

 

 

 

 

 

Sykes Quarries  September 8th at 10am, leader, Peter Del Strother

Meet at Sykes quarries SD628519 on the Trough road at 10 am.

It is intended to walk the Lancaster Building stones Geotrail in the afternoon, provisionally meeting by the Queen Victoria memorial, Dalton square Lancaster at 2 pm (diversion to a coffee and cake shop highly likely)

Visit to Sykes Quarries SD628519, on the Trough Road.
Car parking is available circa 200m south of the quarries on the east side of the road. If this parking area is full there are a few other small parking areas within a few hundred metres or so, and a large area about 1km southeast towards Dunsop Bridge.
Safety. The two quarries have not been worked for many years and the faces are probably stable. Nevertheless, those wishing to approach quarry faces closely should wear safety helmets. Access to entrances of both quarries involves a couple of hundred metres walking along the single-track Trough Road. Traffic may be a hazard. Both quarries have gently inclined access tracks, once used by quarry vehicles. Quarry floors are uneven with tussocky grass. The west quarry has a short scree slope below the face. There are no stiles. Mobile phones may not function; on the recce mine didn’t. Because of uneven ground, walking boots or similar are the preferred footwear. Overall walking distance will be about a kilometre.
Permission to access the east quarry, Crag Wood, has to be obtained beforehand. The land is owned by UU and let to the farmer at Sykes Farm. GeoLancashire will arrange permission. Access to Bracken Hill Quarry, west of the road, is not restricted.

 

What there is to see:
Crag Wood Quarry is located on the northern limb of the Sykes Anticline. The limestone exposed is the Hetton Beck Limestone, of Chadian age. The approximately 30° north easterly dip levels out at the southern end of the exposure. Although historically described as the Sykes Anticline, the structure is properly described as a pericline, a domal structure, as can be seen on Geological Sheet 59 (Lancaster) and 67 (Garstang). There is a useful cross section on the Garstang sheet. Soft sediment slump structures/slide planes crop out in the quarry face; these predate the folding which is of Namurian age, associated with the Hercynian Orogeny (~290Ma). Within the limestones, colonies of Syringopora are abundant in all orientations. Silicification is common, giving rise to tabular chert and silicified limestone, which sometimes contains crinoid ossicles. Whether the source of the silica is biological, such as from sponge spicules, or from another source will be discussed. In Crag Wood quarry some joint surfaces are coated with baryte

      

 

 

 

 

 

 

 

Lead mining, probably on a small scale, was carried out on both sides of the road. It began in the C16th and was at its most intense from 1866 to 1871. Little remains except for an adit and small scree slopes with fragments of baryte, for instance. The mineral vein strikes ENE WSW. The terrace of houses known as Smelt Mill Cottages, about 1.5km towards Dunsop Bridge, strongly suggests local smelting but no evidence, of slag for instance, has ever been found.
Many of the features seen in Crag Wood Quarry can also be seen in Bracken Hill Quarry, where there is also a scree of what seems to be mine ‘gangue’ including specimens of baryte and, more rarely, galena.
By walking up the succession towards the summit of the Trough Road it is possible to find outcrops of mudstone (Worston Shales, Chadian to Holkerian) and, near the summit, Pendle Grit. We will not be visiting those locations because parking is limited and there is plenty to see in the limestone quarries.
It is likely to take about two hours to do justice to these two quarry localities, but people could leave at any time to suit themselves

Bibliography
Technical Report WA/87/46, Geology of the Trough of Bowland area (SO65 SW). Part of 1:50,000 Sheets 59 (Lancaster) and 67 (Garstang). R A HUGHES
R. L. Gawthorpe & H. Clemmey, 1985. Geometry of submarine slides in the Bowland Basin (Dinantian) and their relation to debris flows
F. Moseley, 1962. The structure of the south-western part of the Sykes Anticline, Bowland, West Yorkshire (as it was then!)
F. Moseley, 1961. Erosion surfaces in the Forest of Bowland.
N. Riley 1990. Stratigraphy of the Worston Shale Group (Dinantian), Craven Basin, north-west England.
Geology Sheet 67, Garstang and associated Memoir.
Geology Sheet 59, Lancaster and associated Memoir

https://www.bgs.ac.uk/downloads/start.cfm?id=1466

gives access to a free download of A lithostratigraphical framework for the Carboniferous successions of southern Great Britain’. This includes the successions in the Craven Basin.

Winter Meetings 2019/2020

1st meeting – Fri 13th Sept at 7.15.

The speaker will be Andy Gize, who is a coal petrologist, now retired from being a lecturer at Manchester University. He will be talking about the relationships between fossil fuels and mineral deposits

2nd meeting – Fri 11th Oct  James Carter, Senior Engineering Geologist from Wardell Armstrong who has visited us before will talk on Iceland

Nov 8th        Frank Nicholson

Dec 6th        Member’s evening

Jan 10th       Details to be announced

Feb 7th        AGM + Peter del Strother – Cyprus

Mar 6th        Lesley Collins

Apr 3rd         Harry Pinkerton

Further details of talks will be publicised as these become available.