Introduction to Geology of Paleozoic Rocks of Hook Head, South West Coast of County Wexford, Ireland
This page describes the Paleozoic outcrops around Hook Head visited during the University College of Dublin (UCDD) 3rd year geology field trip in 2006 led by Peter Haughton and Ian Somerville. It displays:
The Geology exposed at Hook Head provides a snapshot Ireland's Paleozoic history. These Paleozoic sediments accumulated as the Caledonian mountain chain folded and accreted. This mobile crustal welt stretched from West Texas through the North American Appalachian mountain chain to the Caledonian Mountains of Scandinavia. A paleo-geographic reconstrucation can be viewed using the maps of Terry Scotese and Ron Blakey. Hook Head provided evidence of these geologic events as they occurred on the eastern flank of this trend. The maps record the interaction between continental fragments including Gondwana, Laurentia , Baltica and Avalonia.
- Maps, diagrams & notes of local geology by Peter Haughton & Ian Somerville pdf file
- Digital photographs of outcrops are in order they were taken by Christopher Kendall
|The Late Cambrian the Booley Bay formation represents accumulation of deeper water slope sediments. These are part of the sedimentary fill that collected on a trailing margin that was part of the continental terrain that flanked the northern margin of Gondwana and later became the Avalonia continental fragment or microplate.
|The Ordovician Caradocian andesitic lavas, silts and shales record of submarine sedimentary and volcanic fill. This accumulation was a response to the southward subduction of the Iapetus Ocean floor crust beneath Avalonia. This subduction caused the uplift and erosion of the Avalonian continental fragment and the deposition of the mix of sedimentary and volcanic rocks that outcrop along the shore at Duncannon
|The Devonian sediments of the Templeton conglomerate formation and Harry Lock formation are related to the collision of the continental terrains of Laurentia, Baltica and Avalonia. This collision caused the uplft associated with Acadian orogeny. The resulting relief was eroded and sediment was transported both east and west. The eastward movement of sediment resulted in the accumulation of the Old Red Sandstone continental siliciclastics that outcrop at Hook Head.
|The Carboniferous marginal marine clastics of the Porter's Gate formation and the shelf slope to shallow water carbonates of the Hook Head formation represent the products the Variscan orogeny. This orogeny was a response to the collision of Gondwana with the continental mass formed by the previously welded fragments of Laurentia, Baltica and Avalonia. Initially this collision shed clastics eastward (the Porter's Gate formation) and then was followed by a period of crustal stability and carbonate accumulation (the Hook Head formation).
After the assemblage of maps and diagrams the galleries for the field trip are listed in same order that the outcrops of Hook Head were visited on this trip. You can access the appropriate gallery in the table below by clicking on the images to the right.