Tag: DGAG Talk

Talk -The Variscan Orogeny; it’s Causes and Consequences

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: All welcome: £6 non-members (£5 for DGAG members) cash
Booking a seat: contact Chris Webb at email: events@dorsetgeologistsassociation.org
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/

 

 

Talk – A Geological Tour of Namibia

Dorset Geologist’s Association Group (DGAG) will host a talk on the Tuesday 20 February 2024.
Title: A Geological Tour of Namibia
Speaker: Alan Driscole (DGAG member) – forty years in the oil & gas business including the Atlantic margin from the Barents Sea south to …… Namibia
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: From some of the oldest fossils and highest dunes in the world to the largest meteorite, Namibia is a geological treasure house. In this talk we’ll explore the history of Namibia; from the Precambrian to the present day, making a diversion offshore to see how this history has been controlled by the formation and dismemberment of Gondwanaland. We’ll also discuss Namibia’s emerging important for both “old” energy and the energy transition.
Photos A & B: Courtesy of the speaker
A: Dunes at Sossusvlei
B: The Hoba meteorite (with the speaker for scale)

Holiday Rocks Workshop with Talks

Dorset Geologist’s Association Group (DGAG) will host the annual Holiday Rocks Talks & Workshop on the Saturday 21 October 2023.

Theme: Post summer holiday (or indeed from other occasions!) talks of places visited and puzzling over rocks or fossils found. Anyone is welcome to share tales of their holiday rocks/fossils or indeed bring any! If you would like to speak a few words about the rocks/fossils and context even better, any presentation format is fine even paper, models etc! We have tables and a projector and facility to connect to laptops and a screen if required.

Time: start at 2.00 pm; finish approximately 4.00 pm

Venue: Broadmayne Village Hall, Cowleaze Road, Broadmayne, Dorset Exact location using what 3 words: innovate.regarding.poem (link to free app https://what3words.com/about).

Entry Cost: £2 collected on room entry (to cover Tea/coffee & cake)

Booking: Contact DGAG events at email: cwebb48578@aol.com
There is plenty of room but it would be good to know who is coming.

Photo: Foraminifera and Coccolith Fossils from the Kimmeridge Clay Formation, Ammonite zone: Pectinatites pectinatus. Photo is a SEM (Scanning Electron Microscope) image courtesy of J. Poole (DGAG member) and interpretation by C. Webb & Etches Collection.