Investigation of the stratigrphy, maturation and source-rock potential of Carboniferous black shales in the Dublin Basin
Citation:Paulo M. C. Fernandes, 'Investigation of the stratigrphy, maturation and source-rock potential of Carboniferous black shales in the Dublin Basin', [thesis], Trinity College (Dublin, Ireland). Department of Geology, 2000, pp 330
Fernandes TCD THESIS 5794 Investigation of.pdf (PDF) 185.5Mb
The Viséan part of the Dublin Basin stratigraphic succession is dominated turbiditic calcarenites interbedded with grey/black shales. Sedimentological analysis of four exploration wells drilled in the north part of the Dublin Basin revealed that deposition in a carbonate slope to basin settings with predominantly anoxic bottom conditions. The shale lithologies have a considerable composite thickness constituting up to 50% of the whole Viséan succession. Shale lithologies, especially black shales, dominated sedimentation during late Brigantian to early Namurian times throughout the Dublin Basin, as attested by the sections observed in borehole 1453/5 (Rathfeigh), Donore, Altmush Stream and Ardagh Glen. Sandstones become increasingly important through the Namurian reflecting the onset of fluvio-deltaic conditions. The palynological study of the Viséan shale lithologies of the Dublin Basin revealed that their kerogen content consist mainly of algal (bacterial)-derived amorphous organic material (AOM) considered to be oil-prone (Type I/II kerogen). Dilution of the AOM by land plant components is associated in these sections with the coarser turbiditic calcarenite beds and sandstone intervals representing influxes of terrigenous material. The kerogen content of the latest Viséan and early Namurian black shale facies is almost entirely composed of AOM (Type I kerogen), making it one of the best oil source-rock intervals of the studied area. Switching from oil-prone facies to gas-prone facies is observed in the Namurian stratigraphic succession of the Kingscourt Outlier. The majority of the source rocks are gas-prone (Type III kerogen).
Author: Fernandes, Paulo M. C.
Publisher:Trinity College (Dublin, Ireland). Department of Geology
Type of material:thesis
Availability:Full text available