PhD in Geographical and Earth Sciences – Rapid Coastal Change at Slag-Based Anthropogenic Coasts

Start date: 01 October 2025

Anthropogenic coasts are sections of the coast (terrestrial and marine) where anthropogenic activity, particularly deposition of waste material, have impacts on natural systems. Slag – a by-product of iron and steel making – is a voluminous (half a billion tonnes per year globally, and countless billions of tonnes of legacy slag from past iron and steel manufacture) anthropogenic material often dumped in coastal environments which can impact coastal landscapes and ecosystems. 

Slag is a relatively chemically-reactive material (compared to natural rock and sediment) and pilot data suggests slag-based anthropogenic coasts can undergo rapid changes in their physical and chemical properties, e.g. deposition of slag converting a soft coast to a hard rocky coast. Reworking of deposited slag at the coast by wave and tidal processes, followed by rapid lithification of the reworked material creates beach rock platforms made almost entirely out of anthropogenic material. The processes which cause this lithification, and the timescales over which it occurs, are not known. 

This project has the overall aim of determining the processes and timescales of rapid lithification of slag-based anthropogenic coasts. 

Using case study sites in Scotland and NW England, the student will achieve this aim through the following three objectives, which broadly map onto empirical chapters: 

1. O1: map historic and recent changes at anthropogenic coasts

• Hypothesis: lithification of reworked slag-based anthropogenic coasts will result in progradation of the coastline due to hardening

1. O2: determine the process, chemistry and mineralogy of the lithification process

• Hypothesis: lithification will primarily result through calcite cement formation but other mineral cements may occur

1. O3: determine the rapidity of lithification through radionuclide dating of the cement minerals

• Hypothesis: cementation occurs extremely rapidly over a matter of years to decades

Research Approach: 

Objective O1: 

• GIS analysis of historic maps and aerial imagery
• Potentially capture of new UAV imagery

Objective O2: 

• Sampling of material from the case study sites
• Scanning Electron Microscopy, X-Ray Diffraction

Objective O3: 

• Radionuclide analysis which may include the analysis of both atmospheric-derived and Sellafield-derived anthropogenic radionuclides such as 14-Carbon and 241-Americium

Please contact the lead supervisor (John MacDonald, john.macdonald.3@glasgow.ac.uk) for details on how to apply.

Funded project – funding from Marine Alliance for Science and Technology Scotland (MASTS), and the Angus Mitchell (PhD 1964) Bursary. The bursary was established by the late Miriam Carol Mitchell, wife of one of our graduates, Dr (Charles) Angus Mitchell (BSc 1958, PhD 1964) at the University of Glasgow, to support postgraduate students in Earth and Natural Sciences. 

Eligibility: Applicants will likely have a strong Honours BSc (or equivalent) in Geology or an allied subject. An MSc (taught or research) will be advantageous. Applicants are expected to have experience of independent field-based geological mapping and/or laboratory analysis. A driving license would be beneficial but not essential.