Clay minerals

Clay minerals are an integral part of the global water and nutrient cycles. They indicate past environmental conditions and play an important role in catastrophic events.

Clay minerals exist when minerals that originally contain no water are hydrated and altered. These reactions occur in many geological scenarios, from deep Earth processes to deep sea environments to weathering on Earth’s surface.

Clay minerals are important controls of the chemical composition of the crust, oceans and atmosphere, with implications on climate, global mineral evolution and natural resources.

Clays have direct relevance to geohazards, such as crustal faulting, earthquakes and landslides, while the interactions between clays and microorganisms are critical to nutrient transport cycles in the biosphere.

The detailed crystal chemistry of clay minerals is a key indicator of both historic and active geological processes, climate, environmental conditions and biota. The crystal chemistry of clays also tells us about the pathways or mineral reactions, a knowledge than underpins much of modern geological work.

Clay minerals on the surface of Mars are key to unravelling its past habitability.

Examples of our projects

Dynamics of Plio-Pleistocene environments in East Africa

This project is studying lacustrine and peri-lacustrine sediments to reconstruct landscapes and climate in Olduvai 1.7-1.5 million years ago, when the transition from Homo habilis to Homo erectus took place.

Subglacial hydrothermal clays

Mars saw clay formation in hydrothermal settings in a cold climate. We are geologically contextualising complex clay minerals from Icelandic hydrothermal systems to establish environmental controls on in-the-making clay assemblages, useful to reconstruct clay palaeosignatures on Earth and Mars.

Colour perception and measurement

Translation of perceived rock colours on Mars and Earth will provide a fast first rock assessment to guide Mars missions and allow a better exploitation of their high-resolution capabilities.

Mangrove reactor

Mangrove forests are fast clay reactors producing lasting and globally significant chemical modifications to sediments and seawater.

Clays from submarine hydrothermal systems

Clays formed in ocean ridges are similar in composition to the most abundant clay types found on Mars. In-depth characterization of the nature of Earth proxies is helping identification of Martian clays and the environments where they were generated.

Sedimentology and Petrography of the Upper Greensand of the Isle of Wight, Hampshire

An examination of the complex interplay of silica, carbonate and clay diagenesis in these compositionally variable sandstones.