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
Winter program 2018
Professor Steve Donovan – Naturalis, Leyden, Netherlands
He will speak about the geology of Jamaica
Joseph O’Neill, MSc – (date to be confirmed)
A talk on his recent visits to the Yukon in pursuit of gold and to Angola searching for diamonds.
Professor Steve Donovan will lead a field excursion at Cleveleys beach, meeting at 11 am
25 January 2019
The Dalradian of N W Scotland
Annual General Meeting followed by PdS on the “Aspects of the geology of Bhutan”
Recce at the Syke’s anticline, Trough of Bowland
Harry Pinkerton (vulcanologist) will give a talk on “How Volcanoes Work”
31st March Healey Dell and Thurns Head
Leaders Peter Del Strother and Brian Jeffrey
MGA / GeoLancashire joint field excursion.
31st March 2019 – 10.30am at ‘Cowm Water Ski Centre’, off Tong Lane, Whitworth, OL12 8BE (modest parking fee)
Thurns Head quarry, Whitworth (near Bacup, Lancs.), water ski centre car park at SD882188 (leader Arthur Baldwin)
Thurns Head quarry is in Namurian sandstones with mudstones. Spectacular examples of the non-marine bivalve trace
fossil, Lockeia isp., are abundant. Escape shafts of this bivalve were not found on the recce, so the challenge for the day will
be to find an example. An exposure in an old quarry face contains loading structures about a metre across where, at the
time of deposition, incoming sand has deformed soft mud beneath.
There is plenty of evidence of the industrial history of the site. Part of the route is up an impressive inclined stone trackway
with setts in the centre and metre long flat stones for tracks either side. The long stones have grooves worn into them from
long use by quarrymen, perhaps using sleds to transport stone more than a hundred years ago.
The walking distance is about 3km over moorland paths. The stone trackway is potentially slippery in wet weather
Healey Dell Nature Reserve, car park at SD879164 (leader Ron Powell).
The River Spodden flows through Healey Dell nature reserve, in part through a narrow gorge with waterfalls. Ferns and
other damp and shade loving flora abound. There is abundant evidence of the early woollen industry, including a
waterwheel pit for a fulling mill. There are also the remains of a paving slab ‘stone rubbing mill’, used to smooth ripple
marked stone flags. An adit, likely the site of mediaeval siderite mining, can be seen in a mudrock cliff by the side of the
river. The reasons for the formation of siderite will be discussed.
Two faults, one at either end of the reserve, bring the older Upper Namurian, Rough Rock, into juxtaposition with the
younger Westphalian, Lower Coal Measures. The more southerly fault is visible in the gorge. In the river bed are nice
examples of potholes, formed when water born small pebbles and sediment swirl to erode flask shaped holes in the
bedrock. There is also a variety of sedimentary structures in the cliffs on the side of the gorge, where the Rough Rock is well
The walking distance is up to about 4km, mostly on excellent tracks and paths. In one location the riverside path is rather
narrow and potentially slippery in the wet. For those who do not feel confident about it there is an alternative route. The
main route continues along the side of a leat to a mill lodge. The café and associated small visitor centre are not far from
the lodge. Return will be via the railway track over the gorge and thence to the carpark. For those who wish to visit the café
later in the day, there is parking available
Tues 9th April: Brinscall Quarry / Horwich Stone works
Due to a shortage of the original stone, this quarry is now providing stone for the building of the Sagrada Família Cathedral in Barcelona. Some of this stone is being carved at the Horwich works before shipping. Visit details to follow.
Thursday 2nd May Ecton Copper Mines
These mines in the Manifold Valley have been worked from Bronze Age times and are estimated to have produced 100,000 tonnes of ore. We will be hosted by geologists from Ecton Hill Field Studies Association https://www.ectonhillfsa.org.uk/index.html
and the trip will involve a talk on local geology/ mineralisation, a trip around to see surface geology/industrial archaeology and an underground visit. Visit details to follow. (There will be a £10 per person charge for this excursion)
27 June Brimbo/Llay (MGA trip)
Leader Peter Del Strother
Leader: Tim Astrop PhD of Brymbo Heritage Project
For directions – see http://www.brymboheritage.co.uk/find-us/
At Brymbo are the in situ remains of a Pennsylvanian (Upper Carboniferous) ‘forest’, with both
lycophyte and calamite stems in growth position. Stands of Calamites stems are said to be very rare,
(Appleton et al. 2011. The Brymbo Fossil forest).
The base of the exposure contains plant stems up to about half a metre
in diameter in mudstone.
Stems over 1.5m diameter have been observed. Channels cutting through the mudstone can be
observed in a vertical face. Above this is a horizon with siderite nodules and at the top a coal seam of
Westphalian B age.
In September 2017 the Brymbo Heritage Project secured funding of £0.84M from the Heritage
Lottery Fund and is working to secure more to make the site accessible and to cover the fossil plants
which weather rapidly as soon as they are exposed.
The site is associated with a historic iron ore processing complex which includes blast furnaces. The
large maintenance workshop building is currently being restored, with a grant of £1.1M from the BIG
Lottery, to provide a visitor centre.
The excursion will include the industrial archaeology in addition to the geology.
Tim, our guide, is a palaeobiologist.
Bring a packed lunch. It is planned to take lunch at the site as there are outdoor picnic tables.
Walking distance is short, about a kilometre if all the industrial archaeological sites are included.
Conditions underfoot are fairly good, but boots are recommended.
Llay coal mine tip, about 6 miles north west of Wrexham. Meet at 2.00pm
Address: Hanson Cement, Former Llay Main Tip, Llay Road, Llay, near Wrexham, LL12 0TL
Leader: Jason Parry – Quarry Manager, Hanson Cement Padeswood
The coal mine tip is being reworked by Hanson Cement as raw material for cement production. It is
located quite close to Brymbo. Apart from coal we should be able to find cobbles of sandstone
containing plant fossils.
You can read something about the mine at http://www.welshcoalmines.co.uk/North/LlayMain.htm
Walking conditions are fairly good. Walking distance is less than a kilometre. This is an operationalquarry site, so wearing of boots, safety helmet and high visibility jacket or waistcoat is compulsory. If
it is dry it may be dusty and wearing of eye protection will be required.
Peter del Strother
If you have questions, please email firstname.lastname@example.org
Thursday 11 July Bashall Eaves Permo Triassic outlier
Leader Alan Harrison
This will be an evening trip starting from Bashall Eaves…..Limited local parking
Details to follow
Mon 22 July Preesall Salt fields
Leaders G. Williamson and Barbara Gordon
A short, easy and pleasant walk to look at the brine extraction fields of the area known locally as “Over Wyre”, taking in the interesting industrial archaeology and the effect that several collapse structures has had on the area.
There may be time this day to also walk the Sykes anticline in the Trough of Bowland.
Details to follow
Close house mine (date to be announced)
Leader Lesley Collins
Details to follow.
Lancaster building stone (date to be announced)
This will be a Geotrail test run
Details to follow