The stratigraphy and emplacement of the Antrim Lava group, Northern Ireland

Beresford-Browne, Adam Neil William ORCID: 0000-0001-9783-8341 (2024). The stratigraphy and emplacement of the Antrim Lava group, Northern Ireland. University of Birmingham. Ph.D.

	Appendix L - NIRE Borehole Logs (Lonmin)-20241028T094540Z-001.zip Archive Available under License All rights reserved. Download (1GB)
	BeresfordBrowne2024PhD.pdf Text - Accepted Version Available under License All rights reserved. Download (28MB)

Abstract

This thesis presents the work undertaken between October 2019 and December 2023 by Adam Beresford-Browne at the University of Birmingham, funded by the National Environment Research Council (NERC) Doctoral Training Programme, CENTA. The main aim of the research was to examine the stratigraphic relationships and emplacement timing and mechanisms of the igneous and sedimentary rocks of the Antrim Lava Group (ALG) in Northern Ireland, one component of the British & Irish Paleogene Igneous Province (BIPIP) which locally represents a sub-province of the much larger North Atlantic Igneous Province (NAIP). The NAIP was primarily active during the Paleocene and Eocene epochs of the Paleogene period, from the start of the Danian age (c.66 Ma), through the Selandian and Thanetian ages, to the end of the Ypresian age (c.48 Ma).
The research primarily focused on examining geological and geochemical data from ALG borehole core samples held at the Geological Survey of Northern Ireland (GSNI) in Belfast, Northern Ireland. Additionally, palynological sampling and analysis of the interbeds between the basalt lava flows provided key information on the contemporaneous climate and ecology of the ALG, and enabled evaluation of the timespan between successive flood basalt events.
Palynological samples revealed new information about the palaeoenvironment showing that the climate was more temperate than previously thought. This has led to new understandings in this work about the traditionally accepted evolution of ‘laterite’ in the ALG. Namely, these interbeds have more diverse origins, including weathered basalt horizons and sedimentary deposits (fluvial, lacustrine, bogland). Volcanostratigraphic analysis using outcrop facies and geochemistry has shown a number of significant differences in the ALG to the north and south of the Tow Valley Fault, including the absence of the Causeway Tholeiite Member to the south of the fault. This is consistent with a model of syn-tectonic emplacement of the ALG. This research also looks to modern equivalents, specifically the recent flood basalt eruptions of Iceland, as a potential corollary to the ALG, in order to improve our understanding of emplacement mechanisms and the volcanic tempo of the ALG.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

Supervisor(s):