This recent paper discussed the lateral and vertical variation in palynology within individual argillaceous units, as well as lateral variation between different argillaceous units in the same sedimentary complex at similar stratigraphic levels. It aims at a tool for understanding more about why mudstone heterogeneity happens and ways of predicting heterogeneity in the subsurface. In this new article, I look at ways that this initial published work could be extended as part of a reservoir model workflow, by statistically assigning levels of likelihood that mudstone units could act as reservoir baffles.

Palynomorphs are of a similar size to silt particles, and being relatively tough and durable, are capable of being eroded from unconsolidated sediments or solid sedimentary rocks (like silt sized clastic particles) and then included into younger rocks deposited above. In the early days of palynology, this kind of reworking was considered a hindrance to dating and correlation because it was often difficult to tell between reworked and indigenous (i.e. in situ) palynomorphs. However more modern studies have shown the uses of reworking. In this short article I review some of the problems that reworking causes for stratigraphers and geologists, consider some of the uses of reworked palynomorphs helping geologists to understand basin history, and  look forward to useful research on reworking .

Artificial Intelligence is becoming an interesting avenue of research in geology. Recently the International Union of Geological Sciences (IUGS) Deep-time Digital Earth (DDE) team, and partners Alibaba Cloud, have begun to develop a large language model for geology known as GeoGPT. The team also wanted to know if large language model methods could augment a traditional taxonomic key. Could a palynologist sitting by their microscope get some help from a Large Language Model (LLM) in determining a species?

The study of zonate-camerate spores through Transmission Electron Microscopy (TEM) has led to a better understanding of their internal structure and affinities. However TEM is expensive, time consuming, involves concentration on a small number of specimens, and is often inconsistent with practical palynological study which is still overwhelmingly carried out by light microscopy. In this article I show that light microscopy of well-preserved - and particularly of broken specimens - can reveal much about the internal structure of specimens of Vallatisporites.

Taxonomic keys – to help in the identification of species – are a vital tool for palaeontologists and palynologists learning their trade, or for experienced palaeontologists starting in a new area. While they can’t replace the academic expert, they can imitate the expert’s thinking processes and decisions. They can also be useful for students and for standardising practical taxonomy in environments where lots of palynologists work together, for example in companies.

The Levant Arch is a pervasive structural high that runs on a north-northeast trend from eastern Egypt to Turkey, through the Levant. Its existence prompted the use of the term ‘Hercynian Orogeny’ by Gvirtzman & Weissbrod (1984) for the first time in the Middle East, and following this, the widespread use of the term ‘Hercynian unconformity’ across the Arabian Plate. This short article, part of a larger project on the Hercynian unconformity across the Arabian Plate, traces the palynology of the Hercynian unconformity from where the Levant Arch creates a very incomplete Palaeozoic succession to where the Palaeozoic succession is near continuous and without break in the thickest part of the Nafud-Ma’aniya Basin.

I was commissioned by the Subcommission on Permian Stratigraphy (SPS) to write a review of advances in Permian palynology since 2007 for the SPS publication Permophiles. The review was published in Permophiles, 2023, volume 75, p. 22-26 (https://permian.stratigraphy.org/files/permophiles/Permophiles%2075.pdf). But the review is published here also.

Capturing carbon dioxide (CO2) from industrial and power sources and storing it in sub-surface geological formations is an option for reducing emissions into the atmosphere. Palynology (the study of fossil spores and pollen that are common in argillaceous rocks) may have use in the crucial area of the uncertainty caused by geological heterogeneity, specifically the size and arrangement of mudstone baffles to fluid flow. Its use shows how science developed to understand oil and gas extraction can be re-invented to help in the injection and underground management of CO2. Recent work in 2022 and 2023 on Jordanian Permian fluvial clastic sequences has shown how different types of mudstone baffles can be identified by their palynological assemblages. Statistical analysis of palynological assemblages may help in providing an objective, quantitative measure of baffle type and size in the future.

The UK Zechstein (Lopingian, Upper Permian) is a thick pile of carbonate/evaporite sediments that accumulated over a period of several million years. In the past rather sparse palynology and palaeobotanical data hinted at minimal evolutionary change over this period suggesting that palynological subdivision (biozonation) would be difficult. New work on the extraction of palynomorphs directly from UK Zechstein salt, rather than from argillaceous sediments associated with salt - and new data from individual mudstone units like those in Cadeby Quarry suggest that there is potential for more and better palynology in the UK Zechstein. This would support the succession’s increased importance in decarbonisation technologies such as subsurface hydrogen storage.

In palynology, one of the ways to correlate distant sections in different palaeophytogeographic provinces is to use ‘bridge’ taxa – the few taxa which appear to be common to the provinces, despite their other differences. Bridge taxa become very important when there are no other ways to correlate, for example in non-marine sequences with no other fossils, or in sequences that have no dateable ash horizons. The problem is that bridge taxa may not be well described, or that conceptions of them in different palaeophytogeographic provinces may be different where different ‘schools’ of palynology have grown up. Traditional and formal (‘legal’) documentation in scientific journals with a description, diagnosis and types can help us understand taxa, but not their full variability, their ‘taxonomic distance’ from their nearest neighbours or the way that they ‘grade’ into their taxonomic neighbours. We should use the internet more to create galleries of images of key bridge taxa and not be constrained by journal page and plate limits.

Palynologists have been using δ13C of organic matter and palynomorphs (δ13Corg) - as opposed to δ13C from carbonates (δ13Ccarb) - for several decades. I’ve used it quite a lot in academic and commercial contexts for paleoenvironmental reconstruction and correlation. Here’s my non-exhaustive summary of the uses and pitfalls of δ13Corg in palynology.

Palynological and lithological correlation has shown how similar the Carboniferous-Permian glaciogenic and post-glaciogenic rocks of Oman and the Arabian Peninsula are to those of Pakistan. Perhaps this is not surprising given their proximity in plate reconstructions for the time. However the excellent exposure of rocks in the Salt and Khisor ranges allow these succession to be ‘eyeballed’ in a way not possible in Oman and the Arabian Peninsula, allowing largescale 2D and 3D appreciation of the complexities of Middle Eastern Carboniferous-Permian glaciogenic and post-glaciogenic rocks.

Palynology is a key tool to correlate subsurface formations, especially where sub-anhydrite seismic is poor and where there is extreme lithological variation between wells. But palynological zonations are often difficult to relate to the subdivisions of global stratigraphy, hampering their value. In this article I show three ways that these connections can be made, and that palynological zonations can be calibrated.

An old technique re-imagined, reducing uncertainty in CCS sites

Our paper published this week shows how important pilot and demonstration projects (PDPs) are to the success of subsurface energy technologies, for example CCS, BECCS, direct air capture and storage (DACCS), aquifer thermal energy storage (ATES), compressed air energy storage, (CAES), and decarbonising heat through district heat networks (geothermal heat, thermal storage). Although these and other technologies have been studied by geologists at laboratory scale and in models and simulations, they require testing at pilot and demonstration scale and in representative conditions not reproducible in labs and models.

Palynology is usually associated with simple dating or palaeoenvironmental and climate studies, but it can be used to solve larger regional geological problems. One example relates to the origin and history of the Dead Sea Fault famous for its destruction of Jericho. The Dead Sea Fault extends for around 1,000 km, and produced more than 100 km of displacement between the Negev and Jordan. Although the fault in its present form is Miocene in age, an older pre-existing deformed zone was also probably present. Here palynology analysis shows that a precursor to the fault was probably active during the Permian.

The Khuff Formation is one of the most productive natural gas reservoirs in the world with supergiant fields across the offshore Gulf supplying LNG to the rest of the world for many years. But the formation is also fascinating geologically. It can be seen at outcrop all over the Middle East and its precursor beds - known as the ‘basal Khuff clastics’ in Arabia - are well known for their superb plant fossils. These basal Khuff clastics also contain rich fossil pollen and spore assemblages that suggest that the basal Khuff clastics, and by association the base of the Khuff carbonate facies, is highly diachronous

Glacigene rocks are widespread in the Arabian peninsula, a part of the suite of Permo-Carboniferous glacigene rocks that occur across the former continent of Gondwana. The oldest of these rocks in Oman and Saudi Arabia have long been considered late Carboniferous in age, but new evidence might suggest that they are older, perhaps separated from the main episode of the Gondwana Permo-Carboniferous glaciation by as much as 30 million years.

Across the Arabian Plate a stratigraphic gap is present within the Palaeozoic, sometimes known as the Hercynian unconformity. In this small article I explain why the Hercynian unconformity is so important geologically and why palynology is useful in identifying the unconformity, and the beds missing because of the unconformity.

Combined fieldwork and palynology of this type in Jordan and Oman in non-marine Permian alluvial flood plain successions of the Umm Irna and Gharif formations has shown how reconstruction of paleoenvironments could help to understand sand connectivity and the lateral persistence of baffles to fluid flow in subsurface sandstone reservoirs.