Events & Courses

Mud, mud glorious mud…. How glorious is mud as a medium for recording Earth surface process and the passage of time?

The simple answer to this is excellent because of two key factors.

The first factor is that, in general, mud continuously settles out from suspension in quiet water areas such as the deep sea and lakes giving us probably the most continuous stratigraphical record. Secondly the fine-grained and platy nature of mud particles make them an excellent medium for preserving fossils and geochemical signatures by protecting these valuable records of life and changing Earth processes from post depositional changes.

At the same time, the fine-grained nature of mudrocks presents a challenge because they often appear monotonous and unexciting in the field, do not tend to form natural exposures or need to be extracted from the middle of the ocean, tend to lack markers for correlation and can prove challenging to breakdown and analyse. This probably explains why until recent decades they have not received as much detailed attention as other types of sedimentary rock.

Using mudrock successions from different parts of the geological record and particularly the Jurassic, Angela Coe will show how we can:

• reconstruct sea-level change over time
• detect small-scale changes in the global carbon cycle
• measure global chemical weathering rates
• measure how oxygenated the sea-floor was during periods of extreme global warming
• and show how global warming influenced life.

In addition she will also demonstrate how mudrock successions have been used extensively to construct astronomical timescales. These timescales form the highest resolution and most laterally extensive relative geological timescale that we currently have. In addition they are easily integrated with biostratigraphical, geochemical and palaeomagnetic timescales enabling an integrated approach.

Astronomical timescales allow us to measure the rates and duration of many Earth surface processes and hence to understand the mechanisms and timescales over which events and changes occur on the Earth’s surface.

Speaker

The Open University

Angela L. Coe graduated from the University of Durham in 1986 with an honours degree in Geology and Geophysics, from there she went on to the University of Oxford to work as a research assistant on a British Petroleum funded project that was designed to test out the sequence stratigraphy model; this involved extensive field work as well as running some interesting field trips full of heated scientific debate for both British Petroleum and Exxon staff.

In 1992 she wrote up part of this work and was awarded a D.Phil. from the University of Oxford. Her thesis was entitled ‘Unconformities within the Upper Jurassic of the Wessex Basin, Southern England’.  Angela then returned to Durham University as a postdoctoral fellow where she continued her work on Upper Jurassic sequence stratigraphy and started new projects on various periods of climate change in Earth history recorded in mudrocks.

In 1996 Angela joined the Open University as a lecturer in Earth Sciences, rising to senior lecturer in 2002. Angela has remained at the Open University since then and has been involved in the production of eight new courses and the running of many other courses as well as an active research programme.

She has published two popular textbooks ‘The Sedimentary Record of Sea-level Change (Cambridge University Press) and ‘Geological Field Techniques’  (Wiley Blackwell) together with many scientific papers. Angela’s research combines stratigraphy, sedimentology, palaeontology and geochemistry and seeks to understand sea-level and environmental change.

She is a passionate field geologist and teacher and has trained over a dozen PhD students together with many hundreds of Open University graduates. Angela is currently a member of Council of the Geological Society, London, Secretary of the International Subcommission on Jurassic Stratigraphy and a member of the Stratigraphy Commission.