Welcome to the Chemical Sedimentology Group!

We are a diverse group of researchers working on a range of topics spanning the fields of geochemistry, sedimentary geology, Earth history, and geobiology.

What is chemical sedimentology? In his seminal 1971 book, Bob Berner described chemical sedimentology as a “chemical approach to the study of sediments, regardless of how they are classified”. Aqueous geochemistry provides an important framework in which to understand the connections between sedimentary rocks, their precursor sediments, and the physical and chemical conditions that produced them. We use the “chemical approach” as a vehicle to re-animate and explore ancient chemical systems on Earth and Mars, and then look to apply what we learn from the laboratory to the field and under the microscope. This gives us what we think is a unique perspective in disentangling how our planet has changed through time, and how this influenced the evolutionary trajectory of life.

Who we are

Nick Tosca (Principal investigator)

Imad Ahmed (Post-doctoral research fellow)

Rosalie Tostevin (Affiliated research fellow)

Clancy (Zhijian) Jiang (DPhil student)

Ritwika (Ricky) Sengupta (DPhil student; Co-supervised by Stuart Robinson)

Brooke Johnson (DPhil student)

Sascha Roest-Ellis (DPhil student)

Lucy Kissick (DPhil student)

Raphael Pietzsch (DPhil student)

Example research projects (under construction)

The Fe-chemistry of early Mars

Iron formation and the chemistry of Precambrian seawater

Fe(II)-carbonate nucleation and crystal growth kinetics

Bioinorganic chemistry and nutrient crises in Precambrian basins

Carbonate / Mg-silicate geochemistry, sedimentation, and diagenesis

CaCO3 crystal growth and fabric development

The late Proterozoic CaCO3 cycle

Chemical weathering, clay formation, and isotopic fractionation

Collaborators, friends, and group alumni

Alice Ashpitel (MSc student)

Alice Barroll (Laboratory & X-ray diffraction technician; now working at Welsh Water)

Matt Brady (MSc student; now a DPhil student at the University of Cambridge)

Ben Tutolo (Post-doctoral research fellow; now Assistant Professor at the University of Calgary)