Geology Department Postgraduate Web Pages

Name: Aoife O’Halloran

Contact Details

Email: earth@tcd.ie

Sponsor

Science Foundation Ireland

Title of Project

Major global climate fluctuations recorded at low latitude on the Indian Ocean margin during the Paleogene.

Project details

Paleogene (65 - 24 Ma) global warming and cooling events are well documented from the Atlantic and Pacific Oceans. However, there are few data from the Indian Ocean, and low latitudes in particular, with which to test established global climate change models. This project uses high-resolution sampling from new borehole cores in Tanzania and Java to test the sedimentary and primary productivity response to global warming and cooling events in the Indian Ocean during the Paleogene. It also develops the technique of nitrogen isotope chemostratigraphy as a new tool in paleo-oceanographic research.

Name of supervisor

Dr C. J. Nicholas

Postgraduate personal details

I am currently in the very final stages of my Ph.D. write-up, and will graduate by November 2010. I completed my undergraduate degree in Geology in June 2004, also here at TCD. For my undergraduate dissertation I studied a British Paleogene igneous centre, Carlingford, Co. Louth, Ireland. I then worked as a research assistant for my now Ph.D. supervisor, Chris Nicholas, before commencing my Ph.D. during 2005 and 2006, pending funding.

All my undergraduate projects and dissertation involved using geochemical data to analyse geological problems, and recreate ancient systems and ecologies. I have carried this into my postgraduate research, while incorporating a new vein: stable isotopes. Nitrogen isotopes can be utilised in my field areas of Tanzania and Java (Indonesia) as both show remarkably low regional diagenesis and have very organic-rich successions. Both field areas were cored in conjunction with an international team of geologists, the Tanzanian Drilling Project (TDP) led by Prof. Paul Pearson of Cardiff University.

During my time as a postgraduate here I have been lucky enough to tutor undergraduate Geology students, as well as demonstrating for lecturers in practical classes and on field trips. I very much enjoy this part of university life, and so have taken Teaching and Learning courses to improve my teaching abilities. I hope to continue my career as a researcher and a teacher of the geological sciences at many institutions.

Project Start Date

April 2006

Publications

Published Articles

2008      ▪   Donoghue, E., Troll, V., Harris, C., O’Halloran, A., Walter, T.R., Torradod, P.Low-temperature hydrothermal alteration of intra-caldera tuffs, Miocene Tejeda caldera, Gran Canaria, Canary Islands. J. Volcanol. Geotherm. Res., 176, 551-564.

2006      ▪   Nicholas, C.J., Pearson, P.N., Bown, P.R., Dunkley Jones T., Huber, B.T., Karega, A., Lees, J.A., McMillan, I.K., O'Halloran, A., Singano, J.M., Wade, B.S. Stratigraphy and sedimentology of the Upper Cretaceous to Paleogene Kilwa Group, Tanzania. J. Africa Earth Sci., 45, 431-466.

Articles in Preparation

              ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. A record of major Paleogene climate fluctuations along the Tanzanian margin. To be submitted to Paleoceanography.
              ▪   Handley, L., O’Halloran, A., Hawkins, E., Pearson, P.N., Nicholas, C.J., Schouten, S., McMillan, I.K., Pancost, R.D. Increases in terrestrial runoff and seasonal precipitation but no humid climate during the Paleocene-Eocene Thermal Maximum in Tanzania.To be submitted to Geology.

Selected Conference Abstracts

2008      ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. Eocene-Oligocene Transition Across the Indian Ocean: Nitrogen Isotopes and Bottom Water Oxic/Anoxic Pulses. Eos Trans. AGU, 89(53), Fall Meet. Suppl., PP33B-1560.
              ▪   Pancost, R.D., Handley, L., O’Halloran, A., Hankinson, E., McMillan, I.K., Nicholas, C.J., Schouten, S.; Pearson, P. Organic and inorganic proxies for changes in the East African hydrological regime at the PETM. Eos. Trans. AGU, 89(53), Fall Meet. Suppl., PP32A-7
              ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. Productivity and sediment supply from the E-O boundary in Tanzania. Goldschmidt Conference, Geochim. et Cosmochim. Acta, 72, p.A693.

2007      ▪   O'Halloran, A., Nicholas, C.J., Goodhue, R. Paleogene climate variations on the East African margin. Geophys. Res. Abstr., EGU meeting, Vienna, Austria.
              ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. δ15N changes during Paleogene climatic events in organic-rich, marine clays from Tanzania. Eos. Trans. AGU, 88(52), Fall Meet. Suppl., PP43B-1284.

2006      ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. The Paleocene-Eocene Thermal Maximum in Tanzania, East Africa. Irish Geol. Res. Meet., Cork, Ireland.
              ▪   O’Halloran, A., Nicholas, C.J., Goodhue, R. A new gauge for climate change on the East African coast? Colloq. African Geol. XXI, Maputo, Mozambique.

2004      ▪   O'Halloran, A., Troll, V.R., Harris, C., Walter, T.R. Hydrothermal alteration of caldera margin tuffs on Gran Canaria, Canary Islands. Volcan. Magma. Stud. Group Meet., Bath, UK.
              ▪   Troll, V.R., O'Halloran, A., Harris, C., Walter, T.R. Hydrothermal Alteration of Intra-caldera Deposits, Tejeda Caldera, Gran Canaria. Eos. Trans. AGU, 85(49), Fall Meet. Suppl., V43A-14.

Fieldwork photos

Drill site by Kali Kunir, Nanggulan, Java.

Describing core in Nanggulan, before sampling and boxing for storage.

TDP 19 drill site on the road to Mkzambo, Pande Peninsula, Tanzania.

Waiting for core in the Tanzanian field lab where all the descriptions, sampling and dating took place.