Earth Sciences talks

Seismic data is essential for studying planetary interiors and dynamics, yet acquiring high-quality recordings in harsh extraterrestrial environments is far more challenging than on Earth. Despite being collected over five decades ago (1969-1977), the Apollo seismic data is the only available source of lunar seismic data, continuing to provide valuable insights into the Moon’s interior. When AI meets the Apollo seismic dataset, what secrets will be unlocked? Here, I present some fascinating results from applying deep learning to this legacy dataset, including the discovery of Lunar’s long-period signal, the search for the planetary free oscillation, and a tool for automatic disturbance detection and mitigation. These findings demonstrate how modern techniques can extract new knowledge from historic recordings, opening a new window into understanding planetary interiors and revolutionising our approach to lunar seismology.

• Speaker: Juan Li, Institute of Geology and Geophysics, Chinese Academy of Sciences
• Wednesday 07 May 2025, 14:00-15:00
• Venue: Wolfson Lecture Theatre.
• Series: Bullard Laboratories Wednesday Seminars; organiser: ChuanChuan Lu.

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Several rock magnetic parameters have been demonstrated to be related to climate. The concept behind magnetic enhancement is that during soil formation, specific iron minerals are formed depending on soil properties, which depend on amongst others precipitation and temperature. In the mid-latitudes, mainly magnetite and maghemite are formed, and these minerals represent a proxy for ‘soil formation intensity’ in some regions, which is driven by i.a. precipitation. While most studies focus on Eurasian Chernozems due to their rather simple stratigraphy and formation processes, other soil types such as luvisols also show elevated magnetic properties in topsoils in relation to climate.

In this presentation, I will provide a short overview of the concept of using magnetic proxies for (paleo)climate studies. Further, first data from ongoing studies in Europe and India will be presented and discussed in a climate perspective. At this point magnetic properties of last interglacial soils appear clearly stronger than Holocene soil properties, suggesting a wetter than recent last interglacial.

• Speaker: Christian Zeeden, Leibniz Institute for Applied Geophysics
• Wednesday 18 June 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: wb350.

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Several lines of geological evidence from both the marine and terrestrial record tell us that the Antarctic Ice Sheet was much bigger than present at the Last Glacial Maximum. Determining how it has changed in both thickness and extent since then, in particular whether it has undergone any major fluctuations in the last few thousand years, is important for validating ice sheet and glacial-isostatic adjustment models that are used to project future sea level rise.

In this talk, I will present an overview of the emerging evidence for large-scale reversible retreat of the Antarctic Ice Sheet during the mid to late Holocene period. I will discuss the methods with which we can further investigate this phenomenon and present a case study from the Amundsen Sea sector illustrating how cosmogenic nuclide measurements in subglacial bedrock reveal regrowth of the Pine Island-Thwaites Glacier system from a smaller than present configuration in the Holocene. Direct evidence for reversible retreat from this and other locations in Antarctica is urgently needed in order to understand what drives regrowth of ice sheets in warm climates and the conditions under which ongoing retreat could be reversed.

• Speaker: Joanne Johnson, British Antarctic Survey
• Wednesday 07 May 2025, 17:30-19:00
• Venue: Latimer Room, Clare College.
• Series: Quaternary Discussion Group (QDG); organiser: sr632.

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Abstract not available

• Speaker: Tristan McKenzie, Uni of Gothenberg
• Thursday 15 May 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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Sole marks are sedimentary structures that are typically seen on the base of beds and encompass a wide range of forms from flutes to grooves. They are particularly prevalent in lacustrine and deep-marine sediments, but their utility has largely been restricted to palaeocurrent information in marked contrast to most other sedimentary structures which provide information about flow conditions, and thus environments. Whilst their counterparts such as ripples and dunes have remained the focus of extensive research, almost all work on sole marks stopped more than half a century ago. This work from the 1950s to the early 1970s left behind a series of enigmatic observations on the distribution and prevalence of these different structures. These unloved structures are revisited here, and these enigmas addressed. It is shown that sole marks provide a wealth of information that goes far beyond palaeocurrents. They provide information on flow type, flow transformation in space and time, substrate conditions, sediment bypass, and the nature of aqueous sediment gravity flows. In turn, these findings challenge most of our previous understanding of sole marks, that has stood for the past 60-70 years. Certain types of sole structures, here termed flow-induced interfacial deformation structures (FIDS), also produce a range of complex patterns. In turbiditic sequences these patterns have in many cases been misidentified as MISS – microbially induced sedimentary structures. The identification of MISS is in turn often used to imply shallow water conditions within the photic zone, and consequently, this can lead to misidentification of environments.

• Speaker: Jeff Peakall, University of Leeds
• Tuesday 27 May 2025, 12:00-13:00
• Venue: Department of Earth Sciences, Tilley Lecture Theatre.
• Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.

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Abstract not available

• Speaker: Isabel Papanagnou
• Friday 16 May 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: Zachary Sudholz
• Friday 20 June 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: Sergei Lebedev ( University of Cambridge)
• Friday 23 May 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: John Rudge
• Friday 06 June 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: Zachary Sudholz
• Friday 20 June 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: James Jackson
• Friday 13 June 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: John Rudge
• Friday 06 June 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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• Speaker: Alex Copley
• Friday 02 May 2025, 16:00-17:00
• Venue: Tea Room, Old House.
• Series: Bullard Laboratories Tea Time Talks; organiser: David Al-Attar.

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Abstract coming soon

• Speaker: Tolulope Olugboji, University of Rochester
• Wednesday 18 June 2025, 14:00-15:00
• Venue: Wolfson Lecture Theatre.
• Series: Bullard Laboratories Wednesday Seminars; organiser: Tom Merry.

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The radiation of animals across the Ediacaran-Cambrian transition is one of the most transformational events in Earth history, representing a step change in the evolution of the biosphere. While fossils from the Cambrian are readily recognised as belonging to extant groups, those from the late Ediacaran Period document organisms with distinctive forms and no counterparts among living species. This has resulted in a number of different phylogenetic interpretations, ranging from animals to fungi to an extinct Kingdom but with little historical consensus. In this talk, I will focus on the rangeomorphs – frond-like taxa with ‘fractal’ branching – which are among the oldest Ediacaran macrofossils. My work uses morphogenetic pattern to produce a phylogenetic bracket for the rangeomorphs and this study of Ediacaran developmental biology has identified them as animals and stem-group eumetazoans to the exclusion of alternatives. Rangeomorphs thus occupy a critical position in the tree of animal life, post-dating the origin of true tissues and body axes, but likely pre-dating the origins of a gut and other defining eumetazoan characters. This conclusion enables us to integrate rangeomorphs into debates concerning the mode of early animal evolution, for example, in the influence of the evolving regulatory genome on the evolution of animal complexity. Some authors have suggested that a step-change in the regulation of early-acting genes implicated in development may explain the burst of morphological variety which underpins the Cambrian Explosion. However, our data suggest that rangeomorph growth was conserved and predictable with a morphogenetic strategy that was highly regulated, demonstrating that the most ancient eumetazoan fossils known already manifest evidence of complex developmental regulation. Instead, we suggest that the evolution of the rangeomorphs (and other Ediacaran macrofossils) may have catalysed the explosion of morphological variety observed during the Cambrian Explosion by promoting the diversification of novel phenotypes and behaviours through the introduction of space- and time-limited resources, resulting in a rougher fitness landscape than earlier in Earth history. Previous studies have implicated a roughening of the fitness landscape as a potential driver for the Cambrian Explosion but this hypothesis remains untested. Using eco-evolutionary simulations we propose that morphological disparity is an emergent property of a roughening fitness landscape providing a possible mechanism for saltational jumps in the evolution of morphological disparity through time, including during the Cambrian Explosion.

• Speaker: Frances Dunn, Oxford University Museum of Natural History & University of Oxford
• Tuesday 10 June 2025, 12:00-13:00
• Venue: Department of Earth Sciences, Tilley Lecture Theatre.
• Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.

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Copper is an essential component in most clean energy technologies and fundamental to the success of the global green energy transition. It is mainly sourced from porphyry copper deposits (PCDs), which are metal-rich magmatic-hydrothermal systems typically associated with subduction zones. However, PCDs are rare and proving increasingly difficult to find. They are also high tonnage (100–1,000 Mt) and low concentration (average production grade is 0.53% Cu), so enormous volumes of rock must be extracted to retrieve tiny amounts of metal. As the global demand for copper surges to meet ambitious green energy targets, society is confronted with the dual challenge of locating increasingly elusive PCDs while prioritising those with the lowest potential environmental impact. This means finding the most copper-rich (highest-grade) deposits, which require the smallest amount of extraction and processing, and thus create the least damage to the environment.

The exhumation history of a PCD plays an important role in determining its copper grade. During the initial “hypogene” stage of mineralisation, rapid exhumation is required to advect heat towards the surface, allowing metal-carrying magmas and fluids to transport their cargo into the shallow crust. To maximise ore grades, exhumation must then slow considerably so the deposit can linger close to the surface where secondary “supergene” enrichment by oxygenated groundwater water takes place. In this talk, I will present an example from the Eocene-Oligocene copper belt in northern Chile, which is the world’s premier PCD province, but disappears to the north as it approaches the Peruvian border. By combining U-Pb zircon geochronology, Al-in-hornblende geobarometry, low-temperature (U-Th-Sm)/He thermochronology, and thermal-kinematic modelling to track exhumation histories, I will show that (1) both the rate and timing of exhumation are critical in determining the potential of an area to host high-grade PCDs; and (2) northward disappearance of the copper belt close to Peru is due to higher exhumation rates in that area, which prevented supergene enrichment and potentially led to loss of deposits via surface erosion.

Mineralogical Society Distinguished Lecturer 2024–25

• Speaker: Frances Cooper, University College London
• Tuesday 03 June 2025, 12:00-13:00
• Venue: Department of Earth Sciences, Tilley Lecture Theatre.
• Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.

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Abstract not available

• Speaker: Tristan McKenzie, Uni of Gothenberg
• Thursday 15 May 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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Abstract not available

• Speaker: Dan Toy, IEEF
• Thursday 01 May 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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Abstract not available

• Speaker: Jeff Peakall, University of Leeds
• Tuesday 27 May 2025, 12:00-13:00
• Venue: Department of Earth Sciences, Tilley Lecture Theatre.
• Series: Department of Earth Sciences Seminars (downtown); organiser: Dr Rachael Rhodes.

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Abstract not available

• Speaker: Emma Lepinay, IEEF
• Thursday 08 May 2025, 11:30-12:30
• Venue: Open Plan Area, Institute for Energy and Environmental Flows, Madingley Rise CB3 0EZ.
• Series: Institute for Energy and Environmental Flows (IEEF); organiser: Catherine Pearson.

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