Detrital U–Pb zircon dating of lower Ordovician syn-arc-continent collision conglomerates in the Irish Caledonides
Clift, Peter D.
Draut, Amy E.
Long, Hoang Van
Chew, David M.
Schouten, Hans A.
MetadataShow full item record
The Early Ordovician Grampian Orogeny in the British Isles represents a classic example of collision between an oceanic island arc and a passive continental margin, starting around 480 Ma. The South Mayo Trough in western Ireland preserves a complete and well-dated sedimentary record of arc collision. We sampled sandstones and conglomerates from the Rosroe, Maumtrasna and Derryveeny Formations in order to assess erosion rates and patterns during and after arc collision. U-Pb dating of zircons reveals a provenance dominated by erosion from the upper levels of the Dalradian Supergroup (Southern Highland and Argyll Groups), with up to 20% influx from the colliding arc into the Rosroe Formation, but only 6% in the Maumtrasna Formation (~465 Ma). The 24 dominant source regions lay to the northeast (e.g. in the vicinity of the Ox Mountains, 50 km distant, along strike). The older portions of the North Mayo Dalradian and its depositional basement (the Annagh Gneiss Complex) do not appear to have been important sources, while the Connemara Dalradian only plays a part after 460 Ma, when it supplies the Derryveeny Formation. By this time all erosion from the arc had effectively ceased and exhumation rates had slowed greatly. The Irish Grampian Orogeny parallels the modern Taiwan collision in showing little role for the colliding arc in the production of sediment. Negligible volumes of arc crust are lost because of erosion during accretion to the continental margin.
Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Tectonophysics 479 (2009): 165-174, doi:10.1016/j.tecto.2008.07.018.
Showing items related by title, author, creator and subject.
Draut, Amy E.; Clift, Peter D. (Geological Society of London, 2002)Dalradian meta-sediments of the Laurentian margin and mafic intrusions thereof in SW Connemara, Ireland, tectonically overlie meta-rhyolites of the Delaney Dome Formation. The two units are separated by the Mannin Thrust. ...
Crake, Kurtis W. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-06)An analytical method for precidicting the extent of damage in ship collisions is developed. The method calculates both the longitudinal and transverse extents of damage for the struck ship as a function of collision ...
Rawson, Charles E. (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 1998-06)Recent international and domestic regulatory actions have resulted in significant changes to oil tanker designs and intensified attention on predicting tanker environmental performance following groundings or collisions. ...