|
Original Article |
1 1Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EQ, UK (e-mail: nhw1{at}esc.cam.ac.uk)
2 2Gams Bank, Threshfield, Skipton BD23 5NP, UK
3 3School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK
The Acadian (mid-Devonian) deformation in NW Europe has typically been interpreted as the culminating event of the Silurian closure of the Iapetus Ocean. This view has been challenged by the recognition of an intervening early Devonian transtensional event across part of the assembled Laurussian continent. Instead, the Acadian shortening must be driven by a renewed push from the south, involving subduction of the Rheic Ocean, and either flat-slab subduction or impingement of another Gondwana-derived continental fragment. A problem with either hypothesis is the lack of Acadian deformation or even correlative unconformity in the segment of the Rhenohercynian Zone between the Acadian belt and the Rheic suture. The possibility is explored that this Rhenohercynian segment was juxtaposed with the Acadian belt and the Midland Microcraton only during latest Acadian and/or Variscan tectonics. If so, a major lithospheric suture lies buried just south of the Variscan Front, along the Bristol Channel Fault Zone, and the missing Acadian terranes must now lie elsewhere along the orogen. A case is made that they are related to the allochthonous terranes of NW Iberia. In any case, the Acadian event in Europe should properly be regarded as proto-Variscan rather than late Caledonian.
This article has been cited by other articles:
![]() |
J. N. CARNEY, P. ALEXANDRE, M. S. PRINGLE, T. C. PHARAOH, R. J. MERRIMAN, and S. J. KEMP 40Ar-39Ar isotope constraints on the age of deformation in Charnwood Forest, UK Geological Magazine, 2008; 145: 702 - 713. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. TANNER Tectonic significance of the Highland Boundary Fault, Scotland Journal of the Geological Society, 2008; 165: 915 - 921. [Abstract] [Full Text] [PDF] |
||||
![]() |
D.I. SCHOFIELD, J.A. EVANS, I.L. MILLAR, P.R. WILBY, and J.A. ASPDEN New U-Pb and Rb-Sr constraints on pre-Acadian tectonism in North Wales Journal of the Geological Society, 2008; 165: 891 - 894. [Abstract] [Full Text] [PDF] |
||||
![]() |
G. J.H. OLIVER, S. A. WILDE, and Y. WAN Geochronology and geodynamics of Scottish granitoids from the late Neoproterozoic break-up of Rodinia to Palaeozoic collision Journal of the Geological Society, 2008; 165: 661 - 674. [Abstract] [Full Text] [PDF] |
||||