A revised sedimentary and biostratigraphical architecture for the Type Llandovery and Garth areas, Central Wales : a field guide

The guide presents some of the results of collaborative research undertaken by the British Geological Survey, National Museum of Wales, and Leicester and Ghent universities in the Type Llandovery and Garth areas of Central Wales (Figure 1a and b), focusing on the late Ashgill, Llandovery and early to mid Wenlock strata. It is based on an earlier version produced for the Ludlow Research Group (LRG) Annual Field Meeting to the Llandovery and Garth areas in September 2009, but contains new data and interpretations based on significant subsequent discoveries in the Type Llandovery area. It highlights the following:  The significance of the intra-Ashgill Shelvian Event.  A reinterpretation of the Hirnantian glacio-eustatic event.  A revised and unified lithostratigraphy for the Llandovery and Garth areas, which addresses the problems of correlating between the northern and southern Llandovery areas.  New graptolite, acritarch and chitinozoan dating, especially in the Aeronian, Telychian and Wenlock.  The importance of re-sedimentation processes including slumping and synsedimentary sliding within the succession.  The relationship between the Llandovery and the overlying Wenlock successions.