The tectono-sedimentary evolution of the enigmatic Old Red Sandstone terrane of the Northwest Dingle Domain perplexed generations of geologists. The Domain remained largely misinterpreted, unappraised or simply disregarded. Its fundamental impact on regional basin dynamics was grossly overlooked. This integrated sedimentological, stratigraphical and structural research unravels the complexities of this unique red-bed collage. The Northwest Dingle Domain is largely structurally-constrained between two ENE- trending Caledonian structures: the North Kerry Lineament and the Fohemamanagh Fault. It comprises four unconformity-bounded Groups: the Lower Devonian Smerwick Group; the Middle Devonian Pointagare Group; and the Late Devonian Carrigduff and Ballyroe Groups. Their fluvial-aeolian, and locally tidal, sedimentation patterns profile Late Caledonian transpression to Middle-Late Devonian extension. The inherent primary structural control on basin location, development, geometry, sedimentary-fill and preservation is manifest in the Northwest Domain. A hierarchical cyclicity to fluvial-aeolian basin-fill architecture is established in order to differentiate between climatic, tectonic and eustatically-controlled 'sequence stratigraphy' in active strike-slip and extensional syn-rifi basin settings. The Acadian emplacement of the Smerwick Group Terrane set the foundations of the Northwest Dingle Domain. The Smerwick Group documents sandy and gravelliferous ephemeral-fluvial and erg-margin aeolian processes on an ancient terminal fan. The Pointagare Group is cogenetic with the Caherbla Group of south Dingle. Together they record the renewed influx of coarse-grained sediment in the form of transverse alluvial fans and axial braidplains in response to increased tectonism followed by overstep of an erg complex. The Pointagare-Caherbla basin model highlights the fundamental structural control on basin topography, palaeodrainage patterns, provenance, palaeowind directions and sedimentation style in tectonically-active extensional basins. The Ballyroe and Carrigduff Groups record syn-rift basin-margin fluvial and precursive tidally-influenced sedimentation on the active northern margin of the Munster Basin half-graben. These coarse clastic wedges represent feeder zone deposition proximal to the finer-grained distributary zone terminal fan deposits which infilled the Munster Basin to the south.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:287705 |
| Date | January 1998 |
| Creators | Richmond, Lorna Kathleen |
| Contributors | Williams, Brian John |
| Publisher | University of Aberdeen |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=240196 |
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