Dating Norfolk's Fossils

A hippopotamus tooth, collected by Anna Gurney, studied as part of the EQuaTe projectThe Norfolk coast is one of the most important fossil-bearing landscapes in Britain. Its constantly eroding cliffs, beaches, and foreshore exposures provide a rare and ever-changing window into deep time, revealing evidence of ancient environments, climates, and ecosystems. For generations, this coastline has attracted collectors, researchers, and enthusiasts, all drawn by the chance to discover material that helps us better understand the past.

At the University of York, in the NEaar laboratory, we use a dating technique that examines how amino acids and proteins, trapped within fossil material, break down over time. By analysing these changes, we can estimate a fossil's age relative to others from the same region or sequence of deposits. This approach is helping us to study the Norfolk coastline as part of the EQuaTe project, allowing us to date these deposits and compare them with sites across northern Europe. Ultimately, this work sheds light on the timing and nature of early human occupation in these landscapes.

From discovery of fossils on the coast or within existing collections, through preparation, to their role in reconstructing the geological history of Norfolk. While much of this work involves specialist techniques, the process often begins in places familiar to many enthusiastic fossil hunters.

Collecting fossils on the Norfolk coast

Much fossil material from Norfolk is recovered from actively eroding cliffs and beach deposits. Coastal erosion continually exposes sediments of different ages, particularly those associated with the Cromer Forest-bed Formation. These sediments preserve fossils dating mainly from the early Middle Pleistocene (0.5 - 1 million years ago).
Fossils may be found in situ within sediments, or may have been mixed up between deposits. Recording the precise location, sedimentary context, and circumstances of discovery is vital for understanding how the dates relate to the geology. Even when a specimen is collected from the beach, understanding which deposits are being eroded nearby can greatly increase its scientific value.

Preparation of enamel samples in the NEaar lab at the University of YorkAt the University of York, in the NEaar Laboratory, we use a dating technique that examines how Local collectors have played a crucial role in building up the knowledge of the Norfolk coast over many decades, and museum collections often contain specimens gathered long before modern recording practices were established. The faunal collections of Alfred Savin and Anna Gurney have been particularly useful in our investigations. Revisiting these historical and private collections can yield new insights when examined using current methods.

From discovery to documentation

Once a fossil enters a research project at the NEaar facility, whether newly collected or sourced from an existing collection, the first step is documentation. This includes recording provenance, previous identifications, and any associated field notes. For older museum specimens, this can involve detective work, piecing together information from labels, accession records, and historical publications.

Specimens are then assessed for their condition and research potential. Some fossils, particularly robust teeth or shells, may require little preparation. Others need careful cleaning and careful inspection to allow detailed study. The aim is always to preserve as much original material and use as little as we can whilst maximising their scientific value

Preparation and investigation

Amino acid dating can be done on a range of different fossils, for which preparations may vary. For vertebrate fossil teeth, this involves taking a small chip of enamel (~10 mm x 5 mm) and then mechanically cleaning it using precision drilling tools. For smaller or more delicate specimens, such as shells, sediment and dirt may be removed with more gentle cleaning.

A trip to the Norfolk coast in 2022 as part of the EQuaTe projectWhether it is a shell or a vertebrate tooth, the next step is to isolate the amino acids that are locked within the fossil, protected from the external environment by being enclosed within the crystal structure of the tooth or shell. This is important because changes in the external environment or the introduction of contamination might impact our ability to date the fossil.

Next, we split our sample into two sub samples, one to measure the free amino acids and the other to measure those that are bound in chains (forming peptides/proteins). By analysing these two different portions of amino acid we are able to get a better picture of how the amino acids are breaking down and identify samples that might not be suitable for dating. We then prepare our two fractions slightly differently; to measure the bound amino acids we first need to break them apart so that we can accurately measure them, this is done in acid at high temperatures. Once both fractions are prepared, they are analysed on a machine that can separate multiple amino acids and accurately determine their concentrations. This is done on a high performance liquid chromatography (HPLC) instrument.

Why dating matters on the Norfolk coast

Dating fossils from the Norfolk coast is not always straightforward. The sediments exposed are complex, often disturbed by glacial activity, and fossils may be moved from older deposits into younger ones in mixing processes. This makes understanding the timing of events particularly challenging and important.

By combining evidence from multiple sources: sedimentology, fossil assemblages, stratigraphic relationships, and comparison with better-dated sites elsewhere, researchers can build a clearer picture of when particular environments existed.

Accurate dating allows us to place Norfolk's fossils into a wider European and global context. This helps answer larger questions about how landscapes responded to climate change, how species migrated, and how ecosystems reorganised during periods of environmental instability.

Bringing together cliffs, collections, and communities

One of the strengths of research on the Norfolk coast is the way it brings together material from multiple sources. Freshly collected fossils, long-held private collections, and museum specimens all contribute pieces of the same puzzle. In many cases, re-examining old material with new questions in mind can be just as informative as discovering something new on the beach.

The Norfolk coast is constantly changing, and with each winter storm new material is exposed while other deposits are lost. This makes ongoing documentation and study essential. By combining fieldwork, collection-based research, and detailed analysis, we can continue to refine our understanding of this remarkable stretch of coastline.