Geosciences Seminar
at the Department of Environment & Biodiversity (Geology)
Constraining Exhumation and Rift Evolution in the Vosges and Black Forest Using Apatite (U-Th)/He Thermochronology
Fabian Dremel
(Results of his PhD project)
Zusammenfassung: Within Central Europe, remnants of the Variscan orogeny are found today at elevations exceeding 1000 m. Among these remnants are the Black Forest and Vosges Mountains, separated by the N-NE-oriented Upper Rhine Graben, part of the European Cenozoic Rift System, which extends over a distance of more than 300 km. Subsidence of the Upper Rhine Graben began during the Eocene and was accompanied by the uplift of Variscan basement, now exposed in the Vosges Mountains and Black Forest as the western and eastern rift flanks, respectively. Overlying Mesozoic sediments have been extensively eroded, exposing the Variscan bedrock and confining the younger sediments to isolated, higher-elevation areas. This erosional unloading intensified uplift due to flexural compensation with the removal of up to 2 km of sediments.
The Black Forest, in particular, has been the focus of several low-temperature thermochronology studies, including zircon and apatite fission track analyses as well as apatite (U-Th)/He dating, to investigate the thermal history of this region. In contrast, the Vosges Mountains have received significantly less attention, with no published apatite (U-Th)/He ages available. Results from previous studies suggest a complex thermal history for the region, including a transient heating episode during the initial rifting phase, as well as recent hydrothermal events that have influenced the thermochronological measurements. However, the total amount of exhumation and the timing and extent of uplift remain so far unconstrained.
In this study, we aim to further constrain the thermal evolution of the region using 26 new apatite (U-Th)/He ages from two E-W profiles along the rift flanks of the Upper Rhine Graben. Samples were collected from outcrops previously dated using apatite fission tracks or, where unavailable, along new horizontal and vertical profiles. Using a novel 1D landscape evolution model, we were able to reconstruct the temporal evolution of erosion rates and exhumation across rift flanks. We will implement findings from these models to reconstruct the temporal and spatial evolution of this region.
When: Tuesday, 8th April, 2025, 3 p.m.
Where: HS 431, NLW, Hellbrunnerstraße 34, Salzburg
Upcoming seminars:
20.05.2025: Chiara Velasco-Kittlaus – results of her BSc thesis project & Lea Schönleber – results of her MSc thesis project
