Unravelling a long-term multi-event thermal record in the cratonic interior of southern Finland through apatite fission track termochronology

Autor: Paul Andriessen, Glen Murrell
Přispěvatelé: Isotope Geochemistry
Jazyk: angličtina
Rok vydání: 2004
Předmět:
Zdroj: Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy, 29(10), 695-707. Pergamon Press Ltd.
Murrell, G R & Andriessen, P A M 2004, ' Unravelling a long-term multi-event thermal record in the cratonic interior of southern Finland through apatite fission track termochronology ', Physics and Chemistry of the Earth, Part A: Solid Earth and Geodesy, vol. 29, no. 10, pp. 695-707 . https://doi.org/10.1016/j.pce.2004.03.007
ISSN: 1464-1895
Popis: Apatite fission track thermochronology (AFTT) has been applied to the Precambrian basement rocks of southern Finland in an attempt to detect within the long-term thermal history, thermal manifestations in the cratonic interior of tectonic events at the craton margin. The likely subtle magnitude of these manifestations means that AFTT is a useful technique for such a study due to its low temperature sensitivity. A total of 10 samples have been analysed, generating AFTT ages, length statistics and thermal models. Ages range from 313 ± 22 to 848 ± 60 Ma and mean track lengths range from 11.0 ± 1.6 to 13.3 ± 1.8 μm. The data suggests the presence of thermal overprinting of an earlier cooling event. Thermal modelling produces similar results for all samples and typically contains the following major events: (1) two phases of Late-Proterozoic cooling, (2) Late-Silurian re-heating, (3) Cenozoic cooling. The first phase of Late-Proterozoic cooling is interpreted to be due to aulacogen inversion as a result of stress propagation from the collisional tectonics of the Sveconorwegian orogeny. The second phase is discussed in relation to passive margin formation and possible asthenospheric diaper induced relief and exhumation. The Late-Silurian re-heating coincides in time with a proposed Caledonian foreland basin. The Cenozoic cooling is interpreted to represent the latest exposure resulting from North Atlantic Margin formation induced uplift and associated denudation. © 2004 Published by Elsevier Ltd.
Databáze: OpenAIRE