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Thursday October 15th, Dr. Michael Flowerdew of CASP, Cambridge, on “All about feldspars: their utility in critical minerals research, sediment provenance, and their influence on sandstone CCS reservoirs.”
Abstract
The abundance, composition and physical properties of feldspar mean that its research spans many geological disciplines and applications. This utility will be showcased through three linked case studies. Firstly, feldspar Pb isotopic composition is used to locate mineralised lithospheric boundaries within the Lewisian Complex Precambrian gneiss terrane, and advocate for a “two-plate” model for the formation of the Complex. Secondly, the Pb composition and texture of feldspars in the Lower Cretaceous Captain Sandstone in the Central North Sea show that it was sourced from the erosion of a portion of the Lewisian Complex, both directly and via recycling from strata themselves sourced from the Complex, and (3) illustrate though a combination of its feldspar composition and texture and experimental work, how the Captain sandstone, the primary reservoir for the Acorn CCS project, responds to CO2-rich fluids under reservoir conditions, raising possible Acorn project model inaccuracies regarding the impact of feldspar on CO2 injectivity and capacity.

Thursday, September 17th, a talk by Patrick Barnard and Lloyd Jones on ‘Sustained annulus pressure’:
In the early days of exploration in the North Sea (and probably many other basins), the emphasis was on safely drilling to the identified prospect. Hydrocarbon shows in the ‘overburden’ were either missed or recognised by the mud loggers and gas chromatograph, but frequently ignored. The exploration team passed the asset to the development team and no thought given to the shallower ‘shows’. The platform engineers think little of the fact they often find SAP (sustained annulus pressure) and happily spend many years venting the ‘problem’. When the field is finally ’empty’ the decommissioning team move in only to find there is a problem. What to do!

Thursday 16th July, conveniently placed between football matches, after Wimbledon and hopefully after the latest heatwave, we’ll have a cool evening in the RCA, Conwy, with weather-suitable refreshments and an excellent talk delivered by Yannick Santerre:
Evolution of a carbonate-evaporite system: Example of the Eocene Facha reservoir & Hon seal from the Dahab field in the Zallah Trough of the Sirte Basin (Libya)
Abstract: The Eocene (Ypresian) Facha dolomite reservoir and Hon evaporite seal from the Dahab field (Zallah Trough, western Sirte Basin, Libya) recorded the evolution of a marginal-marine carbonate-evaporite system within a subsiding rift graben. The Facha reservoir is made of seven stacked dolomite sub-units (Facha A-F) delimited by continuous to subcontinuous anhydrite layers, forming a compartmentalised “layer-cake” architecture. Performed petrographic analysis reveals lagoonal microfacies assemblages dominated by dasycladacean algae, miliolids and red algae. Established paragenesis indicates important early replacements by fine dolomicrite and anhydrite, as well as intense early leaching, opening many small mouldic and vuggy pores. A major upward evolution of the sedimentary system could have been recognised: the lower part of the Upper Facha exhibits sabkha-like cycles (nodular anhydrites, thin caps, root bioturbations, common subaerial exposures) acting as baffles, whereas the upper part of the Upper Facha displays more salina-like cycles (massive subaqueous anhydrite seals). This contrast and the observed vertical sedimentary evolution reflect a progressive deepening of the Zallah Trough mini-basin throughout the Ypresian. The Facha-Hon succession is interpreted as one long-term (2nd-order) transgressive-regressive sequence, pseudo-analogous to the Arab-Hith formations of the Middle East but deposited under hothouse climatic conditions and with a marine transgressive long-term trajectory. Stacked high-frequency parasequences (4th/5th-order) recorded the marine overflow periods, when sea water level crossed the natural hydrographic barriers (horsts), leading to the filling of the Zallah graben area. This study establishes a tectono-eustatic origin for the studied Ypresian sediments of the Zallah Trough, integrating its main reservoir: the Facha Dolomite Member

This month’s Geoscience Cluster meeting is this Thursday, April 23rd, at 18:00 for 18:30.
Dr. Geraint Wyn Hughes will give a presentation on
“Palaeontology and hydrocarbon aspects of selected Jurassic and Cretaceous formations of Saudi Arabia”.
Exploration and development geologists often request micropalaeontologists to rapidly provide information on the distribution of potential reservoir lithologies, especially when such facies may not be easily determined owing to poor seismic data. Upper Jurassic and Palaeogene evaporites often hinder such interpretations in, for example, the Hanifa (Upper Jurassic, Oxfordian) and Shu’aiba (Lower Cretaceous, Aptian) formations respectively drilled in the Rub’ al Khali desert of Saudi Arabia. Regional detailed studies of the micropalaeontology, macropalaeontology and microfacies can provide the “eyes” to the environments most conducive to the deposition of reservoir lithofacies and often to the location of potential source rocks.

This Thursday, March 26th, 18:00, there will be 2 short talks, each of about 15 – 20 minutes, with time for socialising before, between and after, at the usual venue, the Royal Cambrian Academy, Crown Lane, Conwy, LL32 8AN.
The first talk will be:
Leveraging Remote Sensing and AI-Driven Analysis for Mineral Prospectivity in Oman (Alexandra Scarlet, MSc, Project Exploration Geologist – Viridien Group UK)
Bringing a grounded perspective and real field experience to the world of data science and technology, Alex began her career as a graduate mining geologist working on polymetallic, copper‑rich deposits in Romania before joining Viridien’s Minerals and Mining team. Over the past four years at Viridien (formerly CGG), she has worked as an exploration geologist in a fast‑moving environment, integrating multidisciplinary datasets to evaluate mineral potential and developing practical classification workflows for mining‑related challenges across a range of jurisdictions.
Her presentation focuses on a challenge we’re all familiar with: finding new ore deposits in remote, underexplored, and often topographically difficult terrains. Remote sensing gives us the ability to cover large areas without the access constraints of traditional fieldwork, but the sheer volume and diversity of data being acquired today demand more efficient, scalable approaches to extract meaningful geological insight. Alex will outline how her team tackled this by combining advanced AI and machine learning techniques with geological knowledge and remote sensing expertise applied to one of the world’s best exposed fragments of oceanic lithosphere The Oman Ophiolites.

ModellingRiskAndUncertaintyUsingMultipointStatistics_GWL_260326

The second talk will be given by Barrie Wells, who may be known to some of you as the person who writes these posts, and who is currently trying to decide whether to refer to himself in the first or the third person. He/I will give a talk on
Putting the ‘geo’ back into geostatistics: another new development in its 75 year history.
This talk will be a preview of a presentation at a forthcoming meeting of the GeolSoc and I/he really would appreciate feedback.

On 15th January 2026 Bernard Besly gave a talk on the Etruria Marl, a subject on which he is a widely respected expert, having consulted on, and published papers on, over a 40 year period. The talk was very well received, generating much debate over the potential of the formation as a future resource in addition to its historical importance, with contributions to the discussion from other experts in the audience including Arthur Harrisson, an independent consultant in the field of cement clinker decarbonisation, on which Bernard touched during his talk. We thank Bernard and eagerly await a return visit, as promised. The text of his talk may be found here:

Etruria talk to Geoscience Wales