NEXT WEEKS EVENTS
3rd to 9th December 2018
THE FOLLOWING IS AN EXTRACT FROM BRISTOL AND WEST COUNTRY GEOLOGY CALENDARS
MORE DETAILS CAN BE FOUND IN THE BRISTOL AND THE WEST COUNTRY CALENDARS AND ON THE WEB SITES OF THE RELEVANT SOCIETY OR ORGANISATION.
MONDAY 3rd
Course - Geology of the Bristol and Gloucester Region.
When
Mon, 3 December, 19:30 – 21:30
Where
Wynstones School, Stroud Road, Whaddon, Gloucester (map)
Description
Geology of the Bristol and Gloucester Region.
One of the most varied regions of Britain, spanning the major divisions of the Variscan Front/Bristol Channel-Bray Fault, and the Malvern fault/ Worcester Graben, incorporating rocks varying in age from late PreCambrian to Cretaceous, and three of the terranes making up the geological “jigsaw” of Britain. The course will cover roughly the area covered by the eponymous BGS publication in the British Regional Geology series (3rd edition 1992). Starts Mon 17th September for 10 weeks (not 22nd or29th Oct or 5th Nov), until 10th December Held at Wynstones School, Stroud Road, Whaddon, Gloucester from 7.30-9.30pm on Mondays. Cost £75 (including tea, coffee etc at breaktime!).
Contact Dave Green by email at davegeostudies@gmail.com, by phone at 01594 960858 and by post at Dave Green, Joys Green Farm, Lydbrook, Gloucestershire, GL17 9QU
Tuesday 4th
OUGS Oxford - Lecture
When
Tue, 4 December, 19:30 – 21:00
Where
Earth Sciences Building, South Parks Road, Oxford (map)
Description
Thoughts of a Past President (TBC)
Speaker: Dr Tom Argles
Venue: Earth Sciences Building, South Parks Road, Oxford
Location: Oxford
Date: December 4th 2018 (Tuesday)
Wednesday 5th
thursday 6th
Course - Understanding Geology and Scenery around Ross-on-Wye
When
Thu, 6 December, 10:00 – 10:30
Description
Understanding Geology and Scenery around Ross-on-Wye
Starts September 21st (not 25th Oct or 8th Nov), finishes 6th December.
This 10 week course aims to introduce you to the ways in which the varied and beautiful landscape round our area has come into being. The effects of folds, faults and tectonic dip in exposing different rock types, and the past and present processes of uplift, weathering, erosion and deposition that have acted upon them, will be examined by reference to local scenery. Use will be made of local maps and cross-sections across them, both geological and topographic; together with specimens of local rocks. Contact Paul Mason on 01989 760399. Cost £60 Enrol before 15th September to ensure that the course runs.
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Bath Geol Soc - Lecture
When
Thu, 6 December, 19:30 – 21:00
Where
Bath Royal Literary and Scientific Institution, 16 Queen Square, Bath (map)
Description
Diamond Eruptions
T.M. GERNON - Ocean & Earth Science, University of Southampton, SO14 3ZH
Kimberlite volcanism typically involves the formation of diverging pipes or diatremes (see image below), which are the locus of high-intensity explosive eruptions. The talk will first provide an overview of diatreme formation. I will then focus on a conspicuous and previously enigmatic feature of diatreme fills known as ‘pelletal lapilli’ — well-rounded clasts that consist of an inner ‘seed’ particle with a complex rim, thought to represent quenched juvenile melt. Such clasts are widely documented in a range of pyroclastic successions on Earth, yet are not fully understood. New observations of pelletal lapilli in kimberlites show they coincide with a transition from magmatic to pyroclastic behaviour, thus offering fundamental insights into eruption dynamics and constraints on vent conditions.
We provide strong evidence that pelletal lapilli form by fluidized spray granulation — a coating process used widely in industrial applications, including the chocolate industry. We propose that pelletal lapilli are formed when fluid volatile-rich melts (akin to molten chocolate) intrude into earlier volcaniclastic infill close to the diatreme root zone. Intensive degassing produces a gas jet in which locally-scavenged particles are simultaneously fluidized and coated by a spray of low-viscosity melt. Most fine particles are either agglomerated to pelletal coatings or elutriated by powerful gas flows. The origin of pelletal lapilli is important for understanding how magmatic pyroclasts are transported to the surface during explosive eruptions, where they can be asociated with high diamond grades. A similar origin may apply to pelletal lapilli in a range of alkaline volcanic rocks.
friday 7th
Saturday 8th
Christmas Workshop at Broadmayne Village Hall
When
Sat, 8 December, 10:00 – 15:00
Where
Broadmayne Village Hall, Cowleaze Rd, Broadmayne, Dorchester, Dorset, DT2 8EW (map)
Description
Christmas Workshop with buffet lunch at Broadmayne Village Hall.
10.00am-3.00pm
Booking required for display tables and/or lunch
Sunday 9th
Course - Geology of the Bristol and Gloucester Region.
When
Mon, 3 December, 19:30 – 21:30
Where
Wynstones School, Stroud Road, Whaddon, Gloucester (map)
Description
Geology of the Bristol and Gloucester Region.
One of the most varied regions of Britain, spanning the major divisions of the Variscan Front/Bristol Channel-Bray Fault, and the Malvern fault/ Worcester Graben, incorporating rocks varying in age from late PreCambrian to Cretaceous, and three of the terranes making up the geological “jigsaw” of Britain. The course will cover roughly the area covered by the eponymous BGS publication in the British Regional Geology series (3rd edition 1992). Starts Mon 17th September for 10 weeks (not 22nd or29th Oct or 5th Nov), until 10th December Held at Wynstones School, Stroud Road, Whaddon, Gloucester from 7.30-9.30pm on Mondays. Cost £75 (including tea, coffee etc at breaktime!).
Contact Dave Green by email at davegeostudies@gmail.com, by phone at 01594 960858 and by post at Dave Green, Joys Green Farm, Lydbrook, Gloucestershire, GL17 9QU
OUGS Oxford - Lecture
When
Tue, 4 December, 19:30 – 21:00
Where
Earth Sciences Building, South Parks Road, Oxford (map)
Description
Thoughts of a Past President (TBC)
Speaker: Dr Tom Argles
Venue: Earth Sciences Building, South Parks Road, Oxford
Location: Oxford
Date: December 4th 2018 (Tuesday)
Course - Understanding Geology and Scenery around Ross-on-Wye
When
Thu, 6 December, 10:00 – 10:30
Description
Understanding Geology and Scenery around Ross-on-Wye
Starts September 21st (not 25th Oct or 8th Nov), finishes 6th December.
This 10 week course aims to introduce you to the ways in which the varied and beautiful landscape round our area has come into being. The effects of folds, faults and tectonic dip in exposing different rock types, and the past and present processes of uplift, weathering, erosion and deposition that have acted upon them, will be examined by reference to local scenery. Use will be made of local maps and cross-sections across them, both geological and topographic; together with specimens of local rocks. Contact Paul Mason on 01989 760399. Cost £60 Enrol before 15th September to ensure that the course runs.
--------------------------------------------
Bath Geol Soc - Lecture
When
Thu, 6 December, 19:30 – 21:00
Where
Bath Royal Literary and Scientific Institution, 16 Queen Square, Bath (map)
Description
Diamond Eruptions
T.M. GERNON - Ocean & Earth Science, University of Southampton, SO14 3ZH
Kimberlite volcanism typically involves the formation of diverging pipes or diatremes (see image below), which are the locus of high-intensity explosive eruptions. The talk will first provide an overview of diatreme formation. I will then focus on a conspicuous and previously enigmatic feature of diatreme fills known as ‘pelletal lapilli’ — well-rounded clasts that consist of an inner ‘seed’ particle with a complex rim, thought to represent quenched juvenile melt. Such clasts are widely documented in a range of pyroclastic successions on Earth, yet are not fully understood. New observations of pelletal lapilli in kimberlites show they coincide with a transition from magmatic to pyroclastic behaviour, thus offering fundamental insights into eruption dynamics and constraints on vent conditions.
We provide strong evidence that pelletal lapilli form by fluidized spray granulation — a coating process used widely in industrial applications, including the chocolate industry. We propose that pelletal lapilli are formed when fluid volatile-rich melts (akin to molten chocolate) intrude into earlier volcaniclastic infill close to the diatreme root zone. Intensive degassing produces a gas jet in which locally-scavenged particles are simultaneously fluidized and coated by a spray of low-viscosity melt. Most fine particles are either agglomerated to pelletal coatings or elutriated by powerful gas flows. The origin of pelletal lapilli is important for understanding how magmatic pyroclasts are transported to the surface during explosive eruptions, where they can be asociated with high diamond grades. A similar origin may apply to pelletal lapilli in a range of alkaline volcanic rocks.
Christmas Workshop at Broadmayne Village Hall
When
Sat, 8 December, 10:00 – 15:00
Where
Broadmayne Village Hall, Cowleaze Rd, Broadmayne, Dorchester, Dorset, DT2 8EW (map)
Description
Christmas Workshop with buffet lunch at Broadmayne Village Hall.
10.00am-3.00pm
Booking required for display tables and/or lunch
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