Hertfordshire Geological Society

GA Real Urban Geology Walks
2021-11-07 10:00 - 16:00 UTC | Hertfordshire

GA Virtual Festival of Geology
2021-11-06 09:00 - 17:00 | over Zoom

GA Zoom talk/workshop
2021-10-31 18:30 - 20:30 | over Zoom
on the Wealden (Smokejacks)

Geoconservation - principles into practice
2021-10-07 19:30 - 21:00 | Zoom Talk
given by Dr Colin Prosser (Principle Specialist in Geoconservation, Natural England).
Rearranged from October 2020.

Abstract:
The UK is extremely geodiverse with many geological features and sites of international, national and local importance for research, education, tourism and recreation. However, we are a small country with a large population and our geoheritage is subject to a range of threats. These include development pressure, landfill, coastal and river engineering, neglect and ignorance. Retaining these features and sites for future generations requires us to take action locally, nationally and internationally, both to conserve them and to raise awareness amongst the public and decision makers about their value to science and society. This talk explores some of the broad principles which influence different approaches to geoconservation and drawing upon the work of local geoconservation groups and societies, national associations, government conservation agencies and UNESCO Global Geoparks and World Heritage Sites, illustrates how geoconservation is being put into practice on the ground.

View this talk in the Members’ Section.

The ***cretes of Hertfordshire
2021-09-11 10:00 - 16:00 | Hertfordshire
A field trip in search of Calcrete, Silcrete and Ferricrete in South hertfordshire, led by Mike Howgate.
Calcrete cliffs at Waterford Heath
We will meet up in the car park at Waterford Heath Nature Reserve which is just north of Hertford ( O.S. TL 317150 ) at 10.30 am. This is a small car park much used by dog walkers so it would be best to come in as few cars as possible. Here we can examine spectacular cliffs of calcrete within the glacial gravels where we can find erattic fossils. We will then move on to see silcretes starting with the ‘Balloon Stone’ at Standon Green End where I have arranged for us to park up in the farmyard of Mott’s Spring Farm ( O.S. TL 363199 ).
The Balloon Stone is a sarsen stone moved here from Bengeo in the eighteenth century to celebrate the landing point of the first flight in a balloon in England by Vincento Lunardi. Our final stop of the morning will be in the village of Standon ( O.S. TL 396223 to see their famous Hertfordshire puddingstone boulder – the Standon Stone. Park up in the wide part of the road before you reach the church, then walk past the church and the stone is on a small green as the road curves round to the left. I will explain why I think that this HPS boulder has pagan significance. A sandwich lunch can be picked up at Day’s Bakery in the village.
In the afternoon we will meet up at North Mymms church ( O.S. TL 222045 ) where we can have our pic-nic lunch in the churchyard. Park in the road leading up to the church rather than in the church car park. We will examine the church building stones for examples of ferricretes then look for their source in the surrounding farmland. These has been missed for years despite being noted on the 6” to the mile Geological Survey field slips. This part of the trip will involve a two mile walk along well used tracks so boots are recommended.
SAFETY NOTES
We will cross three country roads and be walking on uneven pavements, rough tracks and across fields. The farmer should have removed his livestock from the ‘Balloon Stone’ field. If not beware of inquisitive sheep.

Ammonites - mythology to modern era
2021-09-09 19:30 - 21:00 | Zoom Talk
given by Dr Mick Oates (Retired: BG)
Abstract: Ammonites are a popular subject, as they are both common and rather attractive planispiral fossils. So it is no surprise that they attracted interest from ancient times. The talk will cover a lot of ground, from early beliefs attached to these petrifactions dug from the ground to the most recent interpretations of how they evolved as molluscs and functioned as a part of Jurassic and Cretaceous ecosystems.
View this talk in the Members’ Section.

HGS Summer Event – Chalk Stream Walk – BoxMoor and Chesham
2021-07-10 10:00 - 16:30 | The Box Moor Trust Centre, London Road, Hemel Hempstead, Hertfordshire, HP1 2RE, United Kingdom
Leaders: Peter Ablett and Paul Jennings
Over the years the River Bulbourne has been heavily compromised by historical changes. In 2013, in conjunction with the Environment Agency and other interested parties, the Box Moor Trust embarked on a restoration project for the Bulbourne.

09:45 meet at Box Moor Trust Center (HP1 2RE)
Walk through the trusts’ meadows following the restored section of the
River Bulbourne with Peter Ablett
13:00 Picnic lunch at the Trust Center – it may be worth brining a deck chair
14:00 Drive to Chesham town centre car park (which one?)
Walk along the Chess in the company of Paul Jennings, Chair of the River Chess Association

For full details click here.
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The Dinosaur - Bird link: A critical overview
2021-07-08 19:30 - 21:00 | Zoom Talk
Given by Mike Howgate (HGS).
Abstract:
To most interested lay-people and even most vertebrate palaeontologists the theory that birds arose from a group of Theropod dinosaurs is now regarded as an incontestable fact. However there are a handful of dissenters from this supposed certainty. I am one.
I will start by outlining the position of Archaeopteryx as the quintessential example of an intermediate between two classes of organisms – reptiles and birds, before considering the various theories which have been put forward to explain which group of reptiles could best be considered the direct ancestor of the avian lineage and whether flight could have originated from the ground – up as suggested by the ‘Dino-Bird link’ supporters.
In the final half of the talk will concentrate on two alleged Dino-Birds which featured prominently in the debate. Sinosauropteryx prima, a compsognathid dinosaur which is supposed to exhibit PROTOFEATHERS and Microraptor gui the alleged four winged flying dinosaur which is an archaeopteryx-like bird and not a theropod dinosaur at all. A more parsimonious ancestor for the avian lineage will be suggested.
View this talk in the Members’ Section.

It's 'Ard Up North: An overview of the Chalk of the Northern Province
2021-06-10 00:00 | Zoom Talk
given by Paul Hildreth (Yorkshire Geological Society).
The Chalk of Yorkshire and Lincolnshire belongs to a sedimentary basin distinct from, and yet closely related to, other late Cretaceous basins in southern England. For many years, geologists attempted to fit the southern biostratigraphy onto the northern succession; rather like fitting a square peg in a round hole! A short, though very significant, paper was published in the Proceedings of the Yorkshire Geological Society (PYGS) in 1978 which re-classified the northern Chalk, exactly 100 years after the first recorded reference to its greater similarity to the succession in Germany than to those of southern England and France. Ironically perhaps, but certainly apt for this meeting, a co-author of the 1978 paper was a native of Hertfordshire and well known to the Hertfordshire Geological Society.
This talk will focus on the lithostratigraphy of the chalks of Yorkshire and Lincolnshire, compare with some levels of the southern succession and present some thoughts on future research. I may also be able to convince you that the spectacular chalk cliffs of Flamborough Head, which provide valuable exposures of the full Chalk succession as well as breathtaking scenery, are well worth a visit!
View this talk in the Members’ Section.

Smith - marks on a landscape
2021-05-13 19:30 - 21:00 | Zoom Talk
given by Dr Peter Wigley (Consultant for Lynx Information Systems & co-author of Strata. – William Smith’s Geological Maps.

Strata. – William Smith’s Geological Maps cover
Abstract
William Smith (1769–1839), surveyor and geologist, was born on 23th March 1769 at The Forge, Churchill, Oxfordshire, the son of the village blacksmith and educated at the village school.
In 1787 Smith became assistant to the land surveyor Edward Webb (1751–1828) at Stow-on-the-Wold, learning to measure and value land. In 1791 the young 22 year old Smith was sent by his employer to survey an estate near High Littleton in Somerset. He made the journey on foot from Stow-on-the-Wold down to Stowey in Somerset, a distance of over 80 miles. It was in Somerset, while surveying the course of a canal, that Smith developed his ideas on strata and the relationship of particular fossils to specific strata. This led to his first geological maps around Bath, Somerset and later to his pioneering 1815 geological map of England and Wales.However, there was much more to Smith than just his maps. He made geological cross-sections, he was a coal finder, land drainer and improver, he worked on land slips, he sunk water wells and built sea defences but most importantly, through his publications, he laid the foundations for the science of stratigraphy.
Through digital technology it has been possible to combine Smith’s maps and other aspects of his work with modern remote sensing data and to visualise his enduring legacy on the landscape of England and Wales.
View this talk in the Members’ Section.

Percy Evans Lecture & Presidential Address "In search of Buronite in Norway"
2021-04-08 19:30 - 21:00 | Zoom Talk
given by Linda Hamling.
View this talk in the Members’ Section.

Science driven by conflict
2021-03-11 20:00 - 21:00 | Zoom Talk
Followed our 2021 AGM and given by Haydon Bailey (HGS).
This talk was not recorded.

2020 AGM
2021-03-11 19:30 - 20:00 | over Zoom

Jungle Volcano
2021-02-11 19:30 - 21:00 | Zoom Talk
given by Prof. Chris Jackson (Imperial College London)
Rearranged from December 2020.
View this talk in the Members’ Section.

The geology of Mars and the rover missions
2021-01-14 19:30 - 21:00 | Zoom Talk
given by Dr Susanne Schwenzer (Open University).
Dr Susanne P Schwenzer is a planetary scientist, who has researched Mars geology, petrology and mineralogy since her PhD. In her talk, she will tell the story of Mars as seen from its rocks: First, there was a (warm?) and wet Mars that saw rivers flowing and lakes forming. At the same time, a period of intense impact cratering shaped the Martian landscape, with its own effects on the mineralogy in the subsurface of the planet. About 4.2 Billion years ago, the Martian climate changed to much dryer conditions, and it remained that way to this day. Most of the evidence for the Martian geologic record comes from orbiters, but landers and rovers have most recently contributed hugely important details that in turn make it possible to interpret the global picture. The talk will briefly discuss several of those missions, especially the Curiosity rover mission and its most important findings.
View this talk in the Members’ Section.

Peak District - From the bowels of the earth to the Garden of Eden
2019-09-19 - 2019-09-22 | Hertfordshire
Summary of Excursion

Some aspects of the Geology of Mayo, Western Ireland
2018-09-06 - 2018-09-09 | Hertfordshire
