- Postgraduate Researcher
Megan Dolan is a postgraduate researcher within the iCRAG Geohazard and Geotechnical Engineering spoke. Megan graduated with a BSc (First Class Hons) in International Field Geosciences having undertaken a joint degree at University College Cork (UCC), Ireland, and the University of Montana, USA. She was awarded the Nichol Prize 2017 from the School of Biological, Earth and Environmental Sciences in UCC for the top ranking geology research project. Megan undertook an extensive mapping project funded by the Montana Bureau of Mines and Geology before joining iCRAG in January 2018. She is currently working on a geotechnical project under the supervision of Dr. Bryan McCabe, a civil engineering lecturer at the National University of Ireland Galway.
Buried valleys are not visible from the surface of the ground, they are carved from bedrock by chemical weathering and later infilled with loose sediment. Megan will map out the shape and extent of one of these valleys in the Galway region which is intended to be used for the placement of a tunnel as part of the N6 Galway City Outer-bypass. Laboratory testing of the infilling sediments will improve our understanding of the nature and origin of this material as well as its implications from an engineering perspective. In addition Megan will examine and differentiate the various Galway limestones, helping to reconstruct the geological history of Galway County and western Ireland.
Buried limestone valleys have been revealed between Galway City and Lough Corrib, some reaching depths greater than 100 m. These geomorphological features, possibly resulting from karstification, are infilled with unconsolidated sediments, including material of likely glacial, fluvial and lacustrine origin. A minimum age of the infilling material is estimated as Upper Pleistocene, given the depth of fill and previous research. Mapping and logging will be conducted as part of a detailed geological investigation of the Viséan bedrock in an aim to discriminate the currently ‘undifferentiated’ limestones. A geophysical study using 2D resistivity along with some targeted drilling will delineate the extent and morphology of one or more of these valley features. A detailed laboratory analysis will examine the unconsolidated sediments to determine their likely age and origin whilst concluding their geotechnical and hydrological properties and sedimentological characteristics.
The results and findings of this project will inform further geotechnical investigation during the development of the Galway City bypass, and will also improve our understanding of Cenozoic landscape in this part of western Ireland.
- Postgraduate Researcher
- Earth Science in Society
- Geohazards and Geoengineering