Research activities

Much of the Earth’s history and most of its subsurface are characterised by anoxia.

In such environments, the chemistry and mineralogy of metals is often dominated by their reactions with dissolved sulfide.

The iron-sulfide system, in particular, is closely linked with the biogeochemical cycling of elements such as C, H, and O. 

The chemistry of pyrite (FeS2) formation influences how chemical and isotopic proxies that geochemists use to interpret ancient environments are recorded in the geological record.

Understanding the chemistry of iron sulfide formation is at the heart of understanding many aspects of the evolution of the Earth’s environment. This has been a long-term, collaborative research programme developing and using laboratory-based experimental methods to establish the details of aqueous phase reactions and mineralogical transformations in the iron-sulfide system. 

Published outputs have included: 

• new insights into pyrite formation mechanisms and Fe analysis, 
• the first quantification of stable isotope fractionation factors for the Fe-S system, and 
• insights into the evolution of the Earth’s atmosphere.

Charles Darwin's 'great dilemma' was why complex life in the form of fossil animals seemed to appear so abruptly in rocks around 540 million years ago (Ma), in what is widely known as the Cambrian Explosion.

Although we now know that many fossils are found in slightly older rocks, nonetheless, the triggers and drivers of the Cambrian Explosion remain highly enigmatic. This revolutionary event follows immediately after a perturbation in the carbon cycle as revealed by carbon isotopes. It is known as the BAsal Cambrian carbon isotope Excursion (the BACE).

Although it has long been known, this event remains highly enigmatic. This is because there is no single stratigraphic section that allows us to create an integrated picture, so that we can reconstruct the exact order of events.

It would need to include:

• where and at what time the key fossils are found
• the geochemistry that can tell us about how the Earth's environment may have changed at this time
• the absolute ages (dates) of the rocks 

This means that our understanding of this profound evolutionary transition remains very uncertain. In this project, we will use unique and new archives of sedimentary rocks derived from drilled, subsurface cores. This enables us to construct a much higher resolution, four-dimensional (temporal-spatial) picture of the evolutionary history of the earliest animals and their environment. These cores are from three diverse locations so that we can compare local to global patterns.

They are:

1. Namibia
2. Brazil 
3. South China

Such cores are unweathered, so they will preserve the most accurate geochemical signatures possible.

We have also assembled a very multidisciplinary team, which combines complementary expertise in:

1. geochronology - the dating of rocks 
2. geochemistry - for reconstructing nutrient and biogeochemical cycles
3. palaeontology - the record of life and evolution
4. mathematical modelling

It will enable us to capture geological information in such a way as to test key hypotheses about the effects of animal evolution on environmental stability.

The European Union-funded ‘PalM’ project addresses the question: how did mammals become so successful? 

The five-year project combines:

• fieldwork in Paleocene rocks in New Mexico
• description of new fossils
• molecular and morphological phylogenetic analyses
• statistical methodology 

It aims to understand better how mammals survived the end-Cretaceous extinction and proliferated afterwards, setting the stage for today’s mammal-dominated world.

This project is supported by a European Research Council starting grant to Professor Steve Brusatte.  It employs several postdocs and PhD students based in Edinburgh, and includes a range of external partners.  Most notably, external partners include:

• New Mexico Museum of Natural History and Science in Albuquerque
•  Carnegie Museum of Natural History in Pittsburgh

This Leverhulme Trust-funded project focuses on an extinct group of crocodile relatives called thalattosuchians, which evolved from land-living ancestors that moved into the ocean.

The project brings together palaeontologists, anatomists, and neurosensory biologists to study thalattosuchians in unprecedented detail. This gives important insight into the general mystery of how major transitions in evolution occur. 

We are testing whether changes to the neurosensory system may have driven the land-sea transition. 

Central to the project is a wealth of computed tomography (CT) data of thalattosuchian skulls, which allows the team to build digital models of the brain, sinuses, and sense organs inside the skull. 

The project employs both a postdoc and PhD student.  It also includes the National Museum of Scotland and a range of international external partners.

The search for very ancient microbial fossils on both Earth and Mars is a profound scientific challenge.  It may ultimately provide extraordinary scientific insights into “where we come from”. 

To succeed, we must learn to distinguish true fossils from “pseudofossils”, which are life-like structures and materials formed by non-biological processes. 

Recent, high-profile controversies indicate that this remains a difficult problem that can only be solved using well-designed experiments to understand how pseudofossils can form.

With support from the Royal Society of Edinburgh and international collaborators, we are leading a programme of experiments.  We aim to discover how pseudofossils might have issued from natural interactions between minerals, fluids, and organic matter on the early Earth and Mars, and how they might be recognised today. 

Building on our recent publications in this field, this work is investigating: 

1. how pseudofossils form in silica- and iron-rich conditions like those on the early Earth and Mars 
2. how they may be distinguished from fossils using high-resolution microscopy and spectroscopy

The European Union-funded ‘PalM’ project addresses the question: how did mammals become so successful? The five-year project combines fieldwork in Paleocene rocks in New Mexico, description of new fossils, molecular and morphological phylogenetic analyses, and statistical methodology to understand better how mammal survived the end-Cretaceous extinction and proliferated afterwards, setting the stage for today’s mammal-dominated world.

This project is supported by a European Research Council starting grant to Professor Steve Brusatte, employs several postdocs and PhD students based in Edinburgh, and includes a range of external partners (most notably the New Mexico Museum of Natural History and Science in Albuquerque and the Carnegie Museum of Natural History in Pittsburgh).

This Leverhulme Trust-funded project focuses on an extinct group of crocodile relatives called thalattosuchians, which evolved from land-living ancestors that moved into the ocean. The project brings together palaeontologists, anatomists, and neurosensory biologists to study thalattosuchians in unprecedented detail. This gives important insight into the general mystery of how major transitions in evolution occur. 

We are testing whether changes to the neurosensory system may have driven the land-sea transition. Central to the project is a wealth of computed tomography (CT) data of thalattosuchian skulls, which allows the team to build digital models of the brain, sinuses, and sense organs inside the skull. The project employs a postdoc and PhD student, and includes a range of international external partners and the National Museum of Scotland. 

Professor Steve Brusatte and his team of postdocs and students (including our MScR Palaeontology and Geobiology students) do regular fieldwork on the Isle of Skye and other Hebridean islands. These are some of the few places in the world that preserve Middle Jurassic (ca. 170 million year old) fossils of dinosaurs, marine reptiles, crocodiles, mammals, and other animals.

Our team have discovered and studied many important fossils, including several tracksites where dinosaurs left their footprints and handprints in ancient lagoons, the new ichthyosaur species Dearcmhara, and several dinosaur and pterosaur fossils that are currently under study. This work has been supported by the National Geographic Society and SSE, and involves the collaboration of the PalAlba team, which unites palaeontologists from across Scotland.