Project title: Geochemical variation of the hydrothermal breccia in the Irish Ore Fields
Researcher: Dr Nick Vafeas
The three main objectives of this research project are to:
1) better refine the stratigraphic architecture of the Lower Carboniferous (up through Arundian-age rocks) and tie this understanding, gained largely from drill data, the currently available seismic data.
2) generate a better scientific understanding of the physical properties of Zn-Pb deposits for geophysical exploration.
3) to acquire more knowledge of the subtle dispersion of elements in rocks surrounding the deposits available for detection with sophisticated analyses for geochemical exploration.
The project consists of the following main research areas:
1) Regional-scale 3-D modelling: This will link with current iCRAG projects (i.e., 3-D modelling, groundwater & minerals) and will focus on the construction of 3-D structural and stratigraphic models for the Irish Midlands and into the northwest basins (Abbeytown area). Using existing datasets, such as surface maps, industry exploration data from drill holes, and newly available seismic data models will be constructed using advanced modelling packages (i.e., Vulcan, GoCAD, Leapfrog, Petrel, etc.) to identify potential potentially favourable structural corridors and mineral deposit targets. This work will require facility with seismic stratigraphic datasets as well as sequence stratigraphy.
2) Geochemical maps construction and analysis: A comprehensive analysis of geochemical variations linked to the Irish Zn-Pb orefield will concentrate on Zn, Pb and Cu analyses coupled with other elemental abundances associated with feeders (Ni, Co, As). Where necessary, further analysis of geochemical distributions will be performed together with the production of more detailed elemental maps. Investigations will ascertain whether these geochemical anomalies can be linked to potential mineral deposits using available 2D and 3D geological models.
3) Geochemical vectors to mineralization: This research will focus on a) the potential definition of geochemical haloes associated with vents at stratigraphic levels above the Irish stratiform Zn-Pb deposits and will involve: (a) systematic testing of the nature of these haloes to define geochemical vectors linked to underlying deposits; b) isotopic vectors; c) determining the importance of chert by comparing oxygen isotopes from known deposits with those not known to be associated with mineralization; d) metal and sulphur isotopic ratios to identify fluid flow vectors and hydrothermal systems fertility; and e) maturation vector from organic matter as mineral exploration tools.