Cymdeithas Daeareg Gogledd Cymru
North Wales Geology Association
Programme :
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July 2024 - Postponed
Red Wharf Bay/Dwlban Carboniferous Palaeokarst

Saturday 4th February 2024
Annual General Meeting 2024 and Speaker

Wednesday 19th April 2023
Evidence of a dynamic coal swamp locked in ancient lycopods

Wednesday 8th March 2023
An Update on Metal Mines Programme in Wales

Postponed Indefinitely
Underground exploration, Corris slate quarries

July 2024
Field Meeting:
Red Wharf Bay/Dwlban Carboniferous Palaeokarst
Carboniferous geology of the east Anglesey coast

This meeting is organised in conjunction with Geomon in order to promote partnership between the organisations.

We will examine the excellent exposures of karsts of late Dinantian age. The geometries of these karsts are unique within the Carboniferous Limestones of the British Isles. We will consider how these features may have formed. Recently, many workers have favoured a link to global climatic and eustatic sea level changes.

However, more local, tectonic controls of the sedimentary basin margin cannot be ruled out.

Please contact Oighrig Rieder by email or telephone to register your interest, and receive joining instructions.
Booking is essential since space is limited.

4th February 2024
Annual General Meeting &
Speaker: Alastair Baird
Location: Pensychnant Conservation Centre, Conwy LL32 8BJ
To commence at 14:00h, socialising around the kettle with excellent cakes, Lecture from 15:00h

The point at which the Association is open to scrutiny by its members, followed by our invited speaker, Alastair Baird.

Chairman's Note:
The 2024 Annual General Meeting is a potential turning point in the fortunes of our Association. We have not been immune to the disruptive effects of the Covid-19 emergency, in the same way that the national way of life has taken a severe knock. Other societies, religious congregations and interest groups have also felt the effects of changing patterns of socialisation, and indeed the Geologists' Association in London have seen their meetings sink well below a truly viable attendance. In the history of our Association it has been evident that the most important function of the committee has been to organise meetings, and the position of Meetings Secretary has been functionally vacant for several years, notwithstanding Keith Nicholls' co-option to the position on a temporary basis. We do urgently seek a volunteer meetings secretary, whose position will be to liaise with potential speakers and field leaders, maintain a calendar and oversee the process of setting-up meetings at appropriate venues. Support will also come from the Treasurer and other committee members. Outside of the regular business, it will be the principal function of the AGM to appoint a suitable candidate, or decide on the future path of the Association.

The Geology of the Ogwen valley, northern Eryri: Why change the status quo?

Recently, it has become obvious that the published geological history of the Ogwen valley (Late Ordovician volcanism followed by Late Caledonian (Acadian) polyphase deformation), requires significant revision.
Sequential removal of the Caledonian deformation phases shows that the published geometry of the Ordovician volcaniclastic deposits and calderas is erroneous. Unfortunately these published interpretations are now influencing ideas about tectono-sedimentary evolution Eastern Avalonia, the continent on the SE side of the subducted Iapetus Ocean.

Image from (CC BY-SA 2.0).

19th April 2023
Evidence of a dynamic coal swamp locked in ancient lycopods
Speaker: Tom Hughes
Location: Pensychnant Conservation Centre, Conwy LL32 8BJ
To commence at 19:30h, socialising around the kettle from 19:00h

We look forward to hearing from Tom regarding his work on the "Fossil Forest" of Brymbo, nr. Wrecsam.

In association with Bangor University, a KESS 2 East Scholarship project was started, supported partly by European Social Funds through the Welsh Government and partly by the Brymbo Heritage Trust. This is a PhD project based in the Molecular Ecology and Evolution lab in Bangor (MEEB) and Tom Hughes is researching how these ancient plants lived around each other and how they interacted with their environment.

The Brymbo fossil forest is internationally important for its in-situ, growth position Carboniferous plant fossils. My PhD research has aimed to unlock even more information from the rocks and fossils of Brymbo by studying their geochemistry. Stable isotope analysis has allowed us to understand more about the ecology of these plants and how they were so well preserved.

The image originates from the first field meeting to be held at the Brymbo open-cast mine by CDGC/NWGA, before its fossil riches were fully realised. Image © J.Wilkins, 23-Jan-2002

8th March 2023
An Update on the Metal Mines Programme in Wales
Speaker: Louise Siddorn, CNC/NRW
Location: Pensychnant Conservation Centre, Conwy LL32 8BJ
To commence at 19:30h, socialising around the kettle from 19:00h

We hope that you will give a warm welcome to Louise, who is Lead Specialist Advisor at Cyfoeth Naturiol Cymru / Natural Resources Wales. She has worked for several years in pollution control, contaminated land and remediation and has for three years worked for CNC/NRW.

Louise will describe current Welsh Government funded studies dealing with liability issues arising from past metal mining activity. She will focus on current projects in North Wales particularly – including Parys Mountain and Parc mines.

The image shows Parc Mine No 3 Level (Richard Bird, cc-by-sa/2.0) Parc Mine was a most productive working for lead and zinc from around 1860 and was worked up until the 1950s. Apart from a short mineral dressing experiment in 1962-3, by the mid 60s all had come to an end. This picture was taken in 1974, before a major remediation programme to mitigate metalliferous, airborne dusts.

Field Meeting:
Corris Slate Quarries underground exploration
Leader: Mark Waite, Corris Mine Explorers
Braich Goch Mine, Corris, by Machynlleth

This meeting is a follow-on from the very successful and popular meeting held at Cwmorthin in recent years. Whilst there are adrenaline-fuelled adventures for thrill-seekers, this is intended to explore the underground legacy and the geological background to the Welsh slate industry. The underground itinerary is designed specifically for our requirements by Mark and the team at Corris, and intended to last for around 3 hours. Holding an outdoor meeting in March is unusual, but the weather is unlikely to pose risk to this expedition. There will be a charge for this guided trip, though the Association will be off-setting part of the actual cost for members. Safety gear is provided, and wellies if necessary, but overalls and waterproofs are your responsibility. You will be required to understand and sign a declaration of terms and conditions and fitness for the expedition - a copy can be provided in DOCX format prior to the day.

Please contact Jonathan Wilkins by email or telephone to register your interest.
Image courtesy of