Dorset Geologist’s Association Group (DGAG) will host a talk on the Tuesday 22nd April 2025.
Title: The Variscan Orogeny; it’s Causes and Consequences
Speaker: Alan Driscole (DGAG member) who has forty plus years in exploration geology (Oil/Gas) in many parts of the globe including the Atlantic margin.
Time: Talk will start at 7pm; finish approximately 8pm
Venue: Activity Meeting Room: Dorford Centre, Bridport Road, Dorchester, DT1 1RR
Lecture Entry Cost: £6 (£5 for DGAG members) collected on room entry
Booking a seat: Contact DGAG events at email: cwebb48578@aol.com
Talk Description: The talk is another from Alan and on a topic that there have been discussions on at previous talks and field trips. If you’re exploring geology in the southern UK, Ireland or much of Europe it is a subject that comes up regularly so it is timely to review the orogeny, it’s causes, history & influence on later structure through the Mesozoic and Tertiary age rocks.
The Variscan orogeny culminated in final consolidation of the Pangea supercontinent, with closure of the Rheic Ocean and collision between Laurasia and Gondwana. Rather than a simple single collision, the Variscan incorporates several tectonic phases as small micro-continents, originally split off from the margin of Gondwana, which then collided with Laurasia during a 100 million year period from the early Devonian to the end of the Carboniferous. As can be imagined, these events had a profound influence on the structural and environmental development of southern and central Europe during late Palaeozoic, including in England, Wales and Ireland. In this talk we will look at the story of this prolonged orogeny in Europe; how it influenced Carboniferous geology in the southern UK and its subsequent geological development through to the Alpine orogeny, from the mid Cretaceous to mid Tertiary.
Photo: Courtesy of the speaker –is from Millock Haven, Cornwall & shows Variscan chevron folds in Carboniferous Culm. (Can you spot the “Z” or “S” folds! – Editor)
Additional Links:
1. A good summary by the geological society of UK main orogenic phases
https://www.geolsoc.org.uk/Plate-Tectonics/Chap4-Plate-Tectonics-of-the-UK/Variscan-Orogeny
2. An introduction for geological enthusiasts to SW England and the wonderfully named Variscan Coast.
https://variscancoast.co.uk/
Dorset Geologist’s Association Group (DGAG) will host a talk on the Tuesday 18th March 2025.
Title: The Art of Sand from the Isle of Wight to Iowa: Part 2: Iowa
Speaker: Phil James
Time: Talk will start at 7pm; finish approximately 8pm
Venue: Activity Meeting Room: Dorford Centre, Bridport Road, Dorchester, DT1 1RR
Lecture Entry Cost: £6 (£5 for DGAG members) collected on room entry
Booking a seat: Contact DGAG events at email: cwebb48578@aol.com
Talk Description: Details will be forthcoming nearer the date
Photo: Courtesy of the speaker when available, until then for your interest the current introduction photo is from Iowa courtesy of Smithsonian Institution
https://americanart.si.edu/blog/andrew-clemens-sand-art
Additional Links: To be added when available
Dorset Geologist’s Association Group (DGAG) will host a talk on the Tuesday 21st January 2025.
Title: The Art of Sand from the Isle of Wight to Iowa: Part 1: Isle of Wight
Speaker: Phil James
Time: Talk will start at 7pm; finish approximately 8pm
Venue: Activity Meeting Room: Dorford Centre, Bridport Road, Dorchester, DT1 1RR
Lecture Entry Cost: £6 (£5 for DGAG members) collected on room entry
Booking a seat: Contact DGAG events at email: cwebb48578@aol.com
Talk Description: The Art of Sand” part one, “The Isle of Wight” will look at the fascinating 19th century history of the artistic use of 45 million year old (Eocene age) coloured sands of Alum Bay. The presentation will cover the geology, geological history, Alum Bay illustration, and in particular the beautiful glass sand bells (see photo image attached) filled with amazing coloured-sand pictures. Very little is known about one maker who excelled above all others, W. Carpenter. Through illustration and genealogical research Phil has for the first time managed to identify who W. Carpenter was! The talk will also look at the other sand-art form, sand pictures, another thriving industry in Victorian times on the Isle of Wight.
Part 2 of these two talks on the art of sand is scheduled for 18th March. This will cover an even more talented 19th century sand artist who lived on the other side of the Atlantic, in Iowa, USA, and used sands from the Ordovician period, 460 million years old!
Photo: Courtesy of the speaker: beautiful glass sand bells
Additional Links:
1. Isle of Wight: Alum Bay https://www.theneedles.co.uk/landmarks/alum-bay/
