Image Gallery of Rehy Cliffs of Ross Formation
This cliff is situated between Carrigaholt and and Kilbaha on the northern shore of the Shannon Estuary. Here the the Ross Formation is characterized by channeled deepwater fan lobes which feather out into distal wings, and axial channels which are characterized by amalgamated channel fill. As at the Bridges of Ross and Kilbaha there are a series of incised and stacked channels with channel fill that extends beyond the channels as wings (Elliot , et al, 2000; & Elliott, 2000). The diagrams below include a summary diagram from Lien et al., 2003 and a cross section of the eastern portion of the Rehy Cliff from a guide book assembled by Pyles 2007.
Figure from Lien et al 2003 showing the two stage channel filling model for the various channels exposed around Loop head in Co. Clare including Rehy Cliffs.
Phase 1 shows lateral accretion, minimal aggradation, and spill of mudstones and thin-bedded turbidites over the cut bank. Phase 2 shows vertical aggradation, with individual beds scouring into the cut bank, forming steps. The fill consists of amalgamated sandstones. The more the channel aggrades, the more scouring (megaflutes) and spillover of thick-bedded amalgamated sandstones. The model is based on detailed observations, and boxes give figure references to the constituent parts of the model.
Figure from Pyles 2007 of cross section capturing channel filling model for Rehy Cliffs. The fill consists of amalgamated sandstones. The model is based on observations captured in the rocks featured in the gallery above.
The photographs in this gallery were taken by Christopher Kendall, and Peter Haughton. We extend our special thanks to Geoff McGee, the skipper of the vessel Draiocht out of Carrigaholt harbor on the northern flank of the Shannon Estuary in Co-Clare, who transported us to many of the various localities featured in our photographs on two trips, one being the Field Trip Associated with the SEPM in 2008 (Martinsen et al.,2008).
References cited
Elliott, T., 2000 a, Depositional architecture of a sand-rich, channelized turbidite system: the Upper Carboniferous Ross Sandstone Ross Formation, Western Ireland. in P. Weimer, R. M. Slatt, A. H. Bouma, and D. T. Lawrence, eds., Deep-water reservoirs of the world: Gulf Coast Section SEPM Foundation, Twentieth Annual Research Conference, p. 342–373.
Elliott, T., 2000 b, Megaflute erosion surfaces and the initiation of turbidite channels, Geology; v. 28; no. 2; p. 119–122.
Martinsen O., Sullivan M., Pulham A., Haughton P., Harper H., and Elliot T., 2008, Outcrops Revitalized; Tool, Techniques and Applications Kilkee, County Clare, Ireland June 22-27, 2008 Field Guide SEPM Research Conference pp 53
Pyles, D.R., 2007, Field Trip to the Pennsylvanian Ross Sandstone, Western Ireland. Outcrop Analog for submarine Fans deposited in Structurally Confined Basins
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Tuesday, September 24, 2013