What's on
Thursday 13th August: LOCAL RIVERS display, 2-4pm
at The Stables, Eastcote House Gardens
For our Summer Social we're planning a walk along the River Pinn to coinicide with our next drop-in event at The Stables, Eastcote House Gardens. Bring your own rocks to show us and meet our members. No need to register.
(Future Public Display drop-in: 8 October, on the theme of Building Stones)
Drop-in Public Displays
Field Trips
Saturday 8th August: Field Trip to Ware in Hertfordshire, including Scott's Grotto and Ware Museum
Saturday 5th September: Field Trip to Nettlebed and Goring Gap
Saturday 3rd October: Riddlesdown Quarry geoconservation day
October 12th-15th: Residential trip to the Forest of Dean
Saturday 17h October: Keston Common geotrail (LB Bromley) with the London Natural History Society, for Earth Science Week
Please CONTACT US for more information
Wednesday September 9th Monthly Lecture
Online Lecture via Zoom: Geology and Life Lecture Series
Lecture: Dinosaur National Park in Alberta, Canada, by Prof Jon Noad (University of Adelaide)
CONTACT US
2026 Lecture Programme
Lectures are held on Zoom at 8pm on the 2nd Wednesday of the month.
CONTACT US to request link
Jan 14 – Volcanic Britain: When, Where & How, by Prof Nick Petford (Durham University)
Feb 11 – A billion years of sea level change due to changes in plate tectonics and ice caps, by Dr Douwe van der Meer (HHGS)
March 11 – Thames through time - Cornish Flavour, by Ian Mercer (GeoEssex)
April 08 – UK Geothermal Nation - power to the people, by Prof Jon Gluyas (UK National Geothermal Centre, Durham University)
May 13 – AGM followed by Allan Wheeler's travelog from his recent trip to New Zealand
Geology and Life Lecture Series
June 10 – Life and Rocks - A Deep-Time Story of Earth's Transformation, by Dr Ernest Chi Fru (Cardiff University/ Prifysgol Caerdydd)
July 08 – All Fossils Are Rotten: The Science of Death, Decay and Preservation, by Dr Thomas Clements (www.tgclements.com)
September 09 - Dinosaur National Park in Alberta, Canada, by Prof Jon Noad (University of Adelaide)
October 14: Megalosaurus and the Dinosaur Highway, by Dr Emma Nicholls (Oxford University Museum of Natural History)
November 11- The Cambrian Explosion, by Prof Rachel Wood (Edinburgh University)
Christmas Lecture
December 09 - The Influence of Geology on London's Underground Railways, by Jonathan Gammon (Association of Geotechnical and Geoenvironmental Specialists, retired)
What we do
About HHGS ROCK SHOW ONLINE! Field Trips Exhibitions Online Lectures Local Geology Stanmore Gravel Project Maurer's Tectonics Explore Geology HHGS on YouTube Outreach: Contact us
We hold single-theme displays at Brunel University and Eastcote House Gardens throughout the year. (Due to the relocation of Uxbridge Library to smaller premises, our Rock Show was held at Headstone Manor Museum in 2025. We are actively looking for alternative sites for showing our extensive collections.)

Please visit our Rock Show Online:
Look out for news of HHGS in Earth Heritage Magazine, summer and winter editions. Subscribe free of charge to receive notification of publication.
STANMORE GRAVEL PROJECT
We have exposed a section of gravel on Harrow Weald Common which is currently open, so do go and take a look. The 258 bus stops nearby and it's a wonderful location for its view over London and woodland walks. See the Project page for more details.
Photos from 13 June 2026 site visit:
NEW Virtual Building Stones Walk in Central Harrow!
You may remember our series of local Geological Trails from 20 years ago, available as printed brochures from libraries in Harrow and Hillingdon. These are now being updated as Virtual Tours by our Field Secretary, Allan Wheeler, in full colour and high resolution pdf format. Slimmed-down printed leaflets are also being produced for handing out at events and through local libraries.
NEW virtual tour! Building Stones of Central HARROW Virtual Building Stones Tour of UXBRIDGE Virtual Building Stones Tour of PINNER Geotrail: Building Stones of PINNER
ROBERT "Bob" MAURER: "The Rotating Earth and Plate Tectonics"
After more than 30 years with HHGS, our most creative thinker was sadly lost at the end of 2024. His tectonics theory leaves questions as yet unanswered by mainstream geologists.
  • What force is responsible for splitting supercontinents apart?
  • Does momentum play a part in keeping continents moving in the same direction for 10s of millions of years?
  • Are the continents moving from the heavier to the lighter side of the planet, as would be expected using fluid dynamics to model an unbalanced rotating body?
  • Is it possible for subduction to cause a continental plate to move, as is often suggested? Or do the continents move independently? (Bob called this a two-speed system: oceanic plates may move with mantle convection, but continental plates do not.)
  • Do passive margins ever develop subduction? And hence, is the Wilson Cycle actually a cycle? Or does subduction generally occur as a result of a continental plate moving over the top of an oceanic plate?
Keynote speech at 10th Symposium of Tectonics and Structural Geology of Iran, 2024, held in Tabriz and online:
See Bob's Obituary online here.

Click here for details of Bob's life and work.
Formed in 1973, the Society's aim is to advance public appreciation of geology by observation, discussion, field studies, research, illustrated talks and exhibitions. Memberships embraces all age groups from 16 years upwards, regardless of gender or race, and includes those with widely diversified interests. We have a lively program of meetings held on the second Wednesday of each month. Exhibitions at locations throughout the London Boroughs of Harrow and Hillingdon, and elsewhere, give members an opportunity to display aspects of their particular interests and their collections. We also have a good field trip programme to suit all tastes.