GSA Connects 2021 in Portland, Oregon

Paper No. 199-5
Presentation Time: 9:05 AM


JESS, Scott, University of CalgaryGeoscience, 2500 University Drive NW, Calgary, AB T2N 1N4, CANADA, GRÖGER, Heike, Equinor, Stavanger, NL, Norway, PEACE, Alexander, McMaster University, 1280 Main St W, Hamilton, ON L8S 4L8, CANADA and SCHIFFER, Christian, Department of Earth Sciences, Uppsala University, Villavägen 16, Uppsala, 752 36, Sweden

Low-temperature thermochronology has been widely used to study the evolution of landscapes across the North Atlantic region. Apatite fission-track data have been fundamental in resolving how the upper crust has evolved through the interaction of tectonic and climatic processes. However, many of these studies are limited to small sampling areas, meaning conclusions from individual datasets can contrast significantly and complicate regional interpretations. Notably, the source of elevated topography across the region has long been debated, with some authors interpreting multiple large-scale episodic tectonic events have caused widespread uplift onshore, while others postulate tectonic quiescence and isostatic support of the topography.

We present a compilation of published apatite fission-track data from across the North Atlantic to establish regional trends and support regional interpretations. Data from Scandinavia, Svalbard, East Greenland, Britain and Ireland are included, all margins greatly affected by the formation of the North Atlantic in the Mesozoic and Cenozoic. The spread of ages across the crystalline basement of each margin shows predominantly Mesozoic ages, likely related to effects of rifting during this time. Samples from sedimentary basin across Svalbard, East Greenland, Britain, and Ireland show an assortment of Mesozoic and Cenozoic ages, highlighting the wide array of burial histories from onshore strata across the region and the tectonism of the Spitzbergen Orogeny. Finally, fission-track ages adjacent to large igneous centers in East Greenland and Northern Britain show Cenozoic ages consistent with localised heating related to volcanism of the North Atlantic Igneous Province. Greater debate regarding thermal history modelling and comparisons with other radiomimetic dating systems is warranted, however, this compilation highlights important regional trends and has major implications for future interpretations of the onshore.