Trinity College Dublin

Skip to main content.

Top Level TCD Links

Geology Department Postgraduate Web Pages

Name: Stephen Coakley

Stephen Coakley

Contact Details

Tel: +353 (0)1 896 1363
Fax: +353 (0)1 6711199

Title of Project

Deciphering lateral stable isotopic variability across a Cambro-Ordovician carbonate platform

Project details

Sedimentary carbonate rocks contain physical, chemical, and biological records of the Earth’s past. Isotopic measurements of sulphate and sulphide phases preserved in carbonates document secular changes in the sulphur cycle, cataloguing the co-evolution of Earth’s atmosphere, oceans and biosphere. However, as the isotopic record of ancient oceanic conditions becomes better resolved, reports of coeval but discordant geochemical/isotopic proxies are becoming increasingly common. I am interested in deciphering these geochemical records in order to extract meaningful information about the depositional and diagenetic environment in which the samples formed. In particular, my current work focuses on identifying the causes of wide-ranging variability in δ34S records from carbonate associated sulphate (CAS) at coeval locations with fieldwork being conducted across a Cambro-Ordovician carbonate platform in the Argentine Precordillera. My research involves mapping, stratigraphy and detailed sedimentological observations paired with chemostratigraphic data at both kilometre, metre and micron scales. This work combines synchrotron-based x-ray spectroscopy with secondary ion mass spectrometry to map sulphur speciation and isotopic values at the micron-scale within carbonates.

Name of supervisors

Dr Catherine Rose

Collaborators:  Prof. David Fike Washington University in St. Louis
                        Dr. Fernando Gomez Universidad Nacional de Córdoba


Wyse Jackson, P.N., Key, J.R., M.M. and Coakley, S.P., (2014) Epizoozoan trepostome bryozoans on nautiloids from the Upper Ordovician (Katian) of the Cincinnati Arch Region, U.S.A.: An assessment of growth, form and water flow dynamics, Journal of Palaeontology, 88 (3), 475-487. website

Last updated 2 August 2017