geosciences Article Insights into the Thermal History of North-Eastern Switzerland—Apatite Fission Track Dating of Deep Drill Core Samples from the Swiss Jura Mountains and the Swiss Molasse Basin Diego Villagómez Díaz 1,2,* , Silvia Omodeo-Salé 1 , Alexey Ulyanov 3 and Andrea Moscariello 1 1 Department of Earth Sciences, University of Geneva, 13 rue des Maraîchers, 1205 Geneva, Switzerland;
[email protected] (S.O.-S.);
[email protected] (A.M.) 2 Tectonic Analysis Ltd., Chestnut House, Duncton, West Sussex GU28 0LH, UK 3 Institut des sciences de la Terre, University of Lausanne, Géopolis, 1015 Lausanne, Switzerland;
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[email protected] Abstract: This work presents new apatite fission track LA–ICP–MS (Laser Ablation Inductively Cou- pled Plasma Mass Spectrometry) data from Mid–Late Paleozoic rocks, which form the substratum of the Swiss Jura mountains (the Tabular Jura and the Jura fold-and-thrust belt) and the northern margin of the Swiss Molasse Basin. Samples were collected from cores of deep boreholes drilled in North Switzerland in the 1980s, which reached the crystalline basement. Our thermochronological data show that the region experienced a multi-cycle history of heating and cooling that we ascribe to burial and exhumation, respectively. Sedimentation in the Swiss Jura Mountains occurred continuously from Early Triassic to Early Cretaceous, leading to the deposition of maximum 2 km of sediments. Subsequently, less than 1 km of Lower Cretaceous and Upper Jurassic sediments were slowly eroded during the Late Cretaceous, plausibly as a consequence of the northward migration of the forebulge Citation: Villagómez Díaz, D.; Omodeo-Salé, S.; Ulyanov, A.; of the neo-forming North Alpine Foreland Basin.