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.
Laser (U-Th)/He thermochronology of detrital zircons as a tool for studying surface processes in modern catchments Tripathy-Lang, Alka; Hodges, Kip V.; Monteleone, Brian D.; van Soest, Matthijs C. (John Wiley & Sons, 2013-07-26)Detrital mineral thermochronology of modern sediments is a valuable tool for interrogating landscape evolution. Detrital zircon (U-Th)/He thermochronology is of particular interest because zircons are durable and withstand ...
Cheng, Hao; Zhou, Huaiyang; Yang, Qunhui; Zhang, Lingmin; Ji, Fuwu; Dick, Henry J. B. (Nature Publishing Group, 2016-05-17)The existence of ancient rocks in present mid-ocean ridges have long been observed but received less attention. Here we report the discovery of zircons with both reasonably young ages of about 5 Ma and abnormally old ages ...
Mesoproterozoic subduction under the eastern edge of the Kalahari-Grunehogna Craton preceding Rodinia assembly : the Ritscherflya detrital zircon record, Ahlmannryggen (Dronning Maud Land, Antarctica) Marschall, Horst R.; Hawkesworth, Chris J.; Leat, Philip T. (2013-07-11)The reconstruction of the palaeogeography and supercontinent amalgamation processes in the Precambrian is generally guided by the age of magmatic and metamorphic rocks in orogenic belts, which formed along the sutures ...