Women have played an important part in the development of certain aspects of geology in Wales. This talk highlights the forgotten women who contributed so much in so many different ways. From Gertrude Elles to Emily Dix and Ethel Skeat they have given a significant contribution to the understanding and advancement of Welsh geology.

It should be pointed out that Cynthia has also contributed to the understanding of Welsh geology in her position as tutor with the Open University, and as deputy director of the Centre for Science Communication at Chester. Nationally, she serves on the Geoconservation Commission, the UKRIGS Executive and is chair of NEWRIGS. She is represented on the editorial board of Earth Heritage and convenes the International Federation of University Women Committee for the Award of International Fellowships. She is also on the Geological Society of London's Medals and Awards Committee.

If that was not enough, Cynthia is one of the founding members of Cymdeithas Daeareg Gogledd Cymru, having attended the first meeting to discuss the common interests of GA members without any local representation.

Dr. David Jenkins and members of the Parys Underground Group will lead an excursion into the tunnels and workings of the famous Parys Mine on Anglesey. Numbers will be limited to 10 at the absolute maximum because of safety and equipment constraints. If it is necessary to run another trip to accommodate all potential applicants, then it will be in September/October time and will be re-advertised with priority given to the 'reserve' list.

Contact the chairman for booking a place and further details.

A twenty-year study by the British Geological Survey and its collaborators has elucidated the complex sedimentary architecture and geological structure of the Welsh Basin. The basin was the site of deepwater deposition throughout much of Ordovician and Silurian times and the mixed sand-mud succession is dominated by the famous turbidites. Thin, burrowed or laminated mudstones preserved between these resedimented units represent material deposited from suspension (hemipelagites) either during periods when the basin’s bottom waters were well oxygenated (oxic), or when stagnant anaerobic (anoxic) conditions prevailed.

Biostratigraphical work, and the study of abundant fossil graptolites, has allowed the basin’s sedimentary fill to be dated in detail and revealed complex lateral changes in thickness and sedimentary facies. Periods of rapid subsidence during the late Llandovery and early Wenlock were characterised by high rates of sediment accumulation and intra-basinal tectonism. These contrast with intervals of slower sedimentation which record the influence of external processes including global changes in sea level. More recent investigations of the succession on the adjacent shelf have provided further insight into these contrasting processes and events and have underpinned detailed comparisons with successions of the same age preserved elsewhere in the world.

Such comparisons reveal the influence of glacial events on the palaeo-supercontinent of Gondwana. Periods during which oxic bottom conditions prevailed across the Welsh Basin floor equate with episodes of Gondwanan ice advance and global sea level fall; anoxic conditions were introduced and sustained by the elevated sea levels and warmer waters associated with interglacial episodes. The transitions between oxic and anoxic facies in the Welsh Basin therefore provide a record of repeated and linked changes in Lower Palaeozoic climate and oceanic processes and of their environmental impact. The detailed study of these key intervals allows the rate and impact of ancient global warming episodes and their value as analogues of modern climate change to be assessed.

Dr. David Jenkins will be leading a tour of the surface workings of the Parys Mountain area. Taking in the spoil heaps, archaeological remains and a desent into the Great Opencast, this is an excellent introduction to the method of working and the minerals which were exploited. The structure of the syncline with its Silurian mudstones at the core will be demonstrated, and the relationship with the rhyolite rocks of the Ordovician. We have not visited Parys Mountain for many years, and under David's leadership this will be fine opportunity to get the most from one of Britain's most spectacular metal mines.

Contact the chairman for booking a place and further details.