skip to content

Department of Earth Sciences

 

The origins of our orbicular granite

https://blog.esc.cam.ac.uk/?feed=rss - Mon, 28/04/2025 - 12:35
Once a year, a peculiar, polished slab of rock is hauled down from its home on a windowsill near the 1A lab and propped up on the lawn against a row of knees for the annual Sedgwick Club photo. The slab, with its striking black and white circular patterns, has featured in most annual photos …
Categories: Recent news and blogs

The origins of our orbicular granite

Earth Sciences blog - Mon, 28/04/2025 - 12:35
Once a year, a peculiar, polished slab of rock is hauled down from its home on a windowsill near the 1A lab and propped up on the lawn against a row of knees for the annual Sedgwick Club photo. The slab, with its striking black and white circular patterns, has featured in most annual photos …
Categories: Recent news and blogs

Fri 16 May 16:00: Title to be confirmed

Earth Sciences talks - Fri, 25/04/2025 - 14:16
Title to be confirmed

Abstract not available

Add to your calendar or Include in your list

Fri 20 Jun 16:00: Title to be confirmed

Earth Sciences talks - Fri, 25/04/2025 - 09:19
Title to be confirmed

Abstract not available

Add to your calendar or Include in your list

Fri 06 Jun 16:00: Title to be confirmed

Earth Sciences talks - Fri, 25/04/2025 - 09:17
Title to be confirmed

Abstract not available

Add to your calendar or Include in your list

Tue 10 Jun 12:00: The early evolution of animal life and the generation of form

Earth Sciences talks - Thu, 24/04/2025 - 16:30
The early evolution of animal life and the generation of form

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.

Add to your calendar or Include in your list

Tue 03 Jun 12:00: How crustal exhumation rates determine the fate of porphyry copper deposits Mineralogical Society Distinguished Lecturer 2024–25

Earth Sciences talks - Thu, 24/04/2025 - 16:28
How crustal exhumation rates determine the fate of porphyry copper deposits

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

Add to your calendar or Include in your list

Thu 15 May 11:30: TBC

Earth Sciences talks - Thu, 24/04/2025 - 09:21
TBC

Abstract not available

Add to your calendar or Include in your list

Tue 27 May 12:00: tbc

Earth Sciences talks - Tue, 22/04/2025 - 13:43
tbc

Abstract not available

Add to your calendar or Include in your list

Thu 12 Jun 11:30: TBC

Earth Sciences talks - Tue, 22/04/2025 - 09:18
TBC

Abstract not available

Add to your calendar or Include in your list

Cambridge Hosts 2025 Critical Metals Workshop

Earth Sciences news - Mon, 21/04/2025 - 11:51

On the 15-16 th April, Cambridge’s Department of Earth Sciences hosted a workshop broadly focused on the latest developments in critical metals research, with a particular focus on rare earth elements (REEs). The event brought together around 35 international geoscientists working in the critical metals space. Researchers...

Categories: Recent news and blogs