Radioactive heat production variations in the Faroe–Shetland Basin: key new heat production, geological and geochronological data for regional and local basin modelling

Abstract

This study presents the results of a joint Chemostrat–APT study that aimed to produce a suite of radioactive heat production data for basement rocks in the Faroe Shetland Basin to enable more accurate basin modelling to be undertaken. To enable regional studies to be undertaken, the basement has been split into four zones based on similarities. Zone A is formed of high grade metamorphic basement from the Rockall trough (quads 154 & 164) SW of the Laxfordian front. Zone B comprises granodioritic, tonalitic and dioritic Neoarchean aged (2700–2830 Ma) high grade metamorphic basement from the SW of the Rona Ridge and Basin (wells 202/08-1, 204/15-2, 205/161, 205/21-1A, 206/7a-2, 206/08-2, 206/09-2 and 206/12-1) and NE of the Laxfordian front. Zone C contains Neoarchean aged high grade metamorphic basement of a predominantly granitic and quartz rich granitoid composition from the NE of the Rona Ridge (wells 207/01-3, 207/02-1, 208/23-1 and 208/26-1). Zone D differs from the rest of the material in this study in that it is Caledonian ( c. 460 Ma) granitic plutonic basement from Quads 209 (Ereland volcanic centre). Radioactive heat production values were derived from potassium, thorium and uranium data produced from the analysis of eighty-four basement samples by ICP-OES and ICP-MS analysis. Each mapped basement zone was then assigned a mean radioactive heat production value for use in future basin modelling studies; Zone A = 0.21 µWm 3 , Zone B, 0.64 µWm 3 , zone C = 0.88 µWm 3 and zone D = 2.1 µWm 3 . Supplementary material: Tables containing full mineralogical (SI 1) and U-Pb geochronological analytical (SI 2) data at https://doi.org/10.6084/m9.figshare.c.6771540 Thematic collection: This article is part of the New learning from exploration and development in the UKCS Atlantic Margin collection available at: https://www.lyellcollection.org/topic/collections/new-learning-from-exploration-and-development-in-the-ukcs-atlantic-margin