气候变化领域集成服务门户(CCPortal): Peri-Gondwanan Ordovician arc magmatism in southeastern Ireland and the Isle of Man: Constraints on the timing of Caledonian deformation in Ganderia

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DOI	10.1130/B31949.1
	Peri-Gondwanan Ordovician arc magmatism in southeastern Ireland and the Isle of Man: Constraints on the timing of Caledonian deformation in Ganderia
	Fritschle T.; Daly J.S.; McConnell B.; Whitehouse M.J.; Menuge J.F.; Buhre S.; Mertz-Kraus R.; Döpke D.
发表日期	2018
ISSN	167606
起始页码	1918
结束页码	1939
卷号	130 期号:2021-11-12
英文摘要	The timing of and tectonic controls on Ordovician magmatism and deformation within accreted terranes are key elements in reconstructing the generation of the Caledonian-Appalachian orogen. This paper addresses the topic through integrated geochronological, structural, and multi-isotope geochemical investigation of magmatic arc-related peri-Gondwanan rocks of Ganderian affinity in the Leinster-Lakesman terrane in SE Ireland and the Isle of Man. A basaltic andesite from a previously unrecognized volcaniclastic sequence in the Manx Group at Port-e-Vullen on the Isle of Man yielded an age of 472.7 ± 2.8 Ma (secondary ion mass spectrometry [SIMS] zircon U-Pb), and an arc-related rhyolite from the Avoca volcanic sequence in SE Ireland was dated at 463.6 ± 2.6 Ma. Two granitoids from Graiguenamanagh (SE Ireland) yielded ages of 462.0 ± 2.7 Ma (augen gneiss) and 460.5 ± 3.2 Ma (equigranular granite), whereas the Dhoon granite (Isle of Man) was dated at 457.2 ± 1.2 Ma. Each of the granitic rocks from Graiguenamanagh and Dhoon was previously considered to be of Silurian-Devonian age. In addition, two sheets of the Croghan Kinshelagh granite (SE Ireland) yielded indistinguishable ages of 456.9 ± 2.4 Ma and 455.4 ± 2.8 Ma. Multi-isotopic analyses (SIMS zircon oxygen, laser ablation-multicollector- inductively coupled plasma-mass spectrometry [LA-MCICP- MS] zircon Lu-Hf, whole-rock Sm-Nd) on the rocks of the Leinster-Lakesman terrane suggest a significant source contribution from the Ganderian microcontinent, represented by the Early Ordovician metasedimentary Ribband and Manx Groups. Structural relationships at Graiguenamanagh demonstrate a late Middle Ordovician deformation event at ca. 460 Ma. This deformation appears to be equivalent to the widespread D1 event that affected Early Ordovician rocks in SE Ireland and corresponds to the early structures within the East Carlow deformation zone, previously interpreted as an exclusively Devonian structure. Along strike, the early deformation is spatially associated with serpentinite emplacement. The East Carlow deformation zone is interpreted as an intra- Ganderian suture along which separate fragments of a peri-Gondwanan magmatic arc were juxtaposed at ca. 460 Ma. This deformation represents a Caledonian tectonic event that has not been recognized within Ganderia in the Appalachian sector of the orogen. © 2018 Geological Society of America.
语种	英语
来源期刊	Bulletin of the Geological Society of America
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/184987
作者单位	School of Earth Sciences, University College Dublin, Belfield, Dublin 4, Ireland; Irish Centre for Research in Applied Geosciences (iCRAG), Belfield, Dublin 4, Ireland; Geological Survey Ireland, Beggars Bush, Dublin 4, Ireland; Laboratory for Isotope Geology, Swedish Museum of Natural History, Stockholm, SE-104 05, Sweden; Institut für Geowissenschaften, Johannes Gutenberg-Universität, Mainz, 55099, Germany; Department of Geology, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland
推荐引用方式 GB/T 7714	Fritschle T.,Daly J.S.,McConnell B.,et al. Peri-Gondwanan Ordovician arc magmatism in southeastern Ireland and the Isle of Man: Constraints on the timing of Caledonian deformation in Ganderia[J],2018,130(2021-11-12).
APA	Fritschle T..,Daly J.S..,McConnell B..,Whitehouse M.J..,Menuge J.F..,...&Döpke D..(2018).Peri-Gondwanan Ordovician arc magmatism in southeastern Ireland and the Isle of Man: Constraints on the timing of Caledonian deformation in Ganderia.Bulletin of the Geological Society of America,130(2021-11-12).
MLA	Fritschle T.,et al."Peri-Gondwanan Ordovician arc magmatism in southeastern Ireland and the Isle of Man: Constraints on the timing of Caledonian deformation in Ganderia".Bulletin of the Geological Society of America 130.2021-11-12(2018).