Although sulphuric acid caves (SAS Caves) have been known of for over two centuries (Socquet described a SAS cave in Aix-les-Bains in 1801), these caves were considered as "geological oddities". They rank among the "hypogene" caves, and are important for the understanding of void formation not directly connected to present-day meteorology and surface morphology (e.g., hydrocarbon reservoirs, Mississippi valley type Pb-Zn ore deposits). Since the discovery of Lechuguilla Cave in New Mexico and Movile Cave in Romania (both in 1986) speleological and karstological research has intensified and many more SAS caves have been discovered and recognized.

Today over 90 SAS cave occurrences have been reported around the world, and their number is increasing steadily as cavers have started to recognize their typical morphologies and by-products. This talk, prepared in collaboration with Ilenia Maria D'Angeli, will show the distribution of SAS caves in the world, the different typologies, their unique morphology and by-products, their role in understanding landscape evolution, and their intriguing microbiology and biology.

In this talk, I will present data collected from Maaras Cave over the past seven years, focusing primarily on hydrogeology and geomorphology. The Maaras Cave system is located along the northwestern margin of the Aggitis River basin. It contains an active fluvial system fed by a closed karstic basin, the Kato Nevrokopi polje, to the northwest. The cave is formed within the marbles of the Rhodope Massif and exhibits a distinct morphological pattern. It lacks closed loops and follows a hierarchical structure, where lower-order tributaries merge into higher-order passages. The system consists of two main tributaries, an eastern and a western branch—that converge into a single conduit flowing toward the spring a typical branchwork cave following Palmer's classification.

If you want to know more about caves and fossil mammal remains from Mae Hong Son Province, in north-western Thailand, then join me for this talk where I am going to share everything from my most recent research fieldwork in Thailand, in January 2024.

One of the most interesting and important sites that I visited was Tham Lod rock shelter where I sampled teeth fron Eld's deer. Tham Lod is a magnificent and famous cave and a well-stratified archaeological site, where more than 100,000 archaeological items were unearthed during previous excavations. I and my NERC DTP PhD student Laura Hemmingham have had the opportunity to collect samples of over 200 fossil deer teeth, excavated from several Thailand caves and open sites.

Through the Eld's deer project we studied the diet of Pleistocene deer in relation to climate using the methods of dental wear analysis (DWA), mesowear and species distribution models. My research focuses on palaeoecology of the Quaternary and I am analysing tooth material to understand what these animals ate during the Ice Age and how they responded to environmental and ecological changes.

I started caving in 2002 and have participated in multiple caving expeditions with the Hellenic Speleological Society and with speleologists from Vienna University. I completed my undergraduate degree in Geology, and my Masters degree in Palaeontology, in Greece. My PhD in Palaeontology was from Royal Holloway University of London. I moved to London in 2010 and since September 2015 I have been working as a curator in the Natural History Museum (NHMUK). I am responsible for fossil mammals (over 350,000 specimens from around the world). During this talk I will be also presenting tales and projects that I had the opportunity to work on from other European and UK cave sites.

The natural world is full of tiny magnets: in the soil, in the water, and even in caves. These magnets have fascinating histories that can tell us about changes in the Earth's magnetic field, about rainfall and temperature, about soil microbes and even about industrial pollution. While scientists have been studying natural magnets for many years, it is only recently that magnetometers have become sensitive enough to measure the magnetism of cave deposits, like stalagmites and stalactites. This talk will introduce the wonderful world of cave magnetism, focusing particularly on our recent magnetic study of the flooding history of Waipuna Cave, New Zealand.

Abstract not available

The Raking Light team are working with the management at Kents Cavern, Torquay on a project to record and research the myriad inscriptions and other markings left behind by visitors to the cave. Early researchers such as Father John McEnery and William Pengelly noted many of the inscriptions they found but noted that some were already being lost to a covering of calcite. As part of the cave's conservation plan, the aim is to record and photograph the current state of the inscriptions as well as other marks throughout the cave made with chalk, candle smoke and pencil. The project is amassing a wealth of detail about early visitors to the cave and, working with genealogical and historic records, the team hopes to shine a light on the identity of some of these people.

In the late 19th century, inspired by rich paleontological and archaeological finds in temperate caves, scientists began to systematically explore the caves of peninsular Malaya and Borneo. Early speleologists were stymied by what they perceived as a general absence of artefacts, remains, and specialised animal species. Their conclusions led to a colonial perception of Malaya as a land where there is nothing old but nature. By 1900, scientific attention also turned to bat guano, on the cave floors, and how it might be commercially exploited as a phosphate fertiliser source for the growing plantation economy. In the writings of archaeologists, an antagonism developed towards these guano diggers whose excavations disturbed the stratigraphy of potential field sites. This talk will trace the work of subsequent cave archaeologists through the first half of the 20th century, centring on Batu Caves in Selangor, Gunung Pondok in Perak, and Niah Caves in Sarawak. Attempts to establish the prehistory of Malaya and Borneo coincided and interacted, in the 1950s and 60s, with the writing of a history of the new nation of Malaysia. I will conclude by considering the legacies of colonial speleology on research in the last several decades.

Greenland's High Arctic caves represent a unique and largely untapped archive of past environmental change. Since 2015, the Greenland Caves Project has carried out multidisciplinary scientific investigations across several limestone cave systems between 80–82°N in North Greenland, including sites in Kronprins Christian Land and Wulff Land.

These caves host rare but exceptionally well-preserved flowstones that formed during past warm periods when the regional climate was wetter and the ground was warm enough that it did not contain permafrost, thereby allowing water to percolate through the ground and into the caves.

Through a combination of U-Pb dating, stable isotope geochemistry (δ¹⁸O, δ¹³C), trace element analysis, and petrography, The Greenland Caves Project has reconstructed aspects of Greenland's paleohydrology, permafrost dynamics, and atmospheric circulation during the Miocene, between 15 to 5 million years ago.

The cave records complement and extend marine and ice-core data, offering an independent terrestrial perspective on high-latitude climate variability. Ongoing work is focused on refining chronologies, improving paleoclimate proxies in Arctic cave settings, and integrating these records into broader paleoclimate frameworks. These findings highlight the scientific importance of Greenland's caves as high-latitude climate archives and underscore their sensitivity to past and future environmental change.

Hand-in-hand with the recent exploration, conservation and surveying in Redhouse lane Swallet, initial findings have been made on a range of interesting speleogenetic and geological features. In particular, knowledge has been gained on the relict and present day drainage routes in the system that are contiguous with parts of the Wet-Sink-Slaughter Stream Cave. Copious amounts of cryogenic sediments have been found including powdery calcite in the centre of many passages, fluffy mud and other mud mound features, bouldering and perched sediments on passage sides. Running North-South through the centre of the newly found part of Redhouse a prominent monocline structure has been intersected and this geological structure has impacted on passage orientation and character, bringing the cave across and up stratigraphically from the Lower Dolomite Formation into the Crease and Whitehead Limestones. Within the Crease Limestone colourful iron mineralisation and sandstone dykes have been seen in some places and these are likely related to Intra-Carboniferous paleo-karst development. Many of the very large passages found, by far the biggest in the Forest of Dean, follow massive wrench-faults commonly containing impressive breccias many metres in width and horizontal slickensides.

Much remains to be done on recording these and other features before any comprehensive analysis is possible. However, as before with Wet Sink-Slaughter Stream Cave part of the Symonds Yat Cave System, science can point the way to further finds and will continue feeding into the renewed impetus on exploration and digging that has been handsomely rewarded during the last 14 months.