A study of the tectonic and geomorphic history of Scotland using a joint apatite fission track and (U-Th-Sm)/He analysis approach

• Main Author: Amin, Awara
• Format: Thesis
• Language: English
• Published: 2020
• Subjects: QE Geology; Iceland
• Online Access: http://theses.gla.ac.uk/81468/; https://theses.gla.ac.uk/81468/1/2020AminAwaraPhD.pdf

Scotland is part of the NE Atlantic passive margin with geological features and land- scapes that are evidence of a long and complex geological history. A prolonged period of extension, related to the rifting and breakup of Pangea, began in the Late Carbonif- erous and continued through the Mesozoic until breakup and the formation of oceanic crust occurred in the NE Atlantic in the Early Cenozoic. There is evidence that the Scottish landscape and surrounding basins experienced significant uplift in the Early Paleogene. However, whether this uplift can be attributed to tectonic processes re- lated to rifting or to the movement of the hot Iceland mantle plume past the west of Scotland and Northern Ireland at around 65 Ma, is still unresolved. It also remains unknown to what degree the Caledonian Highland mountains in northern Scotland, produced during the Caledonian Orogeny in the Late Devonian, have retained their original topography since they formed. To investigate long term rates of landscape evolution temporally and spatially across Scotland it is essential to constrain the timing and both the rate and amount of denudation during different stages following the Caledonian Orogeny to determine the more likely cause of uplift and erosion, especially in Late Cretaceous-Early Palaeogene. For that, this study employs apatite fission track and apatite (U-Th-Sm)/He thermochronology on samples collected from vertical profiles and from a regional NW- SE transect from the Outer Hebrides in the west towards the central and eastern Grampian Highland. In total 51 rock samples were collected. AFT analysis was performed for 50 of them using EDM and LA-ICP-MS recently installed at the University of Glasgow. For AHe analysis, 281 grains were analysed in total. During the analysis the single grain ap- proach was performed, and the new approach of treating broken grains introduced by Brown et al. (2013) and Beucher et al. (2013) was performed when samples were modelled using QTQt (5.7.0). In addition, the most recent algorithm ...