Variability of the geothermal gradient across two differently aged magma-rich continental rifted margins of the Atlantic Ocean
- The aim of this study is to investigate the shal- low thermal field differences for two differently aged pas- sive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously pub- lished 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive mar- gins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysi- cal data such as seismic observations and the gravity field. We extracted the temperature–depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condi- tion and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradientThe aim of this study is to investigate the shal- low thermal field differences for two differently aged pas- sive continental margins by analyzing regional variations in geothermal gradient and exploring the controlling factors for these variations. Hence, we analyzed two previously pub- lished 3-D conductive and lithospheric-scale thermal models of the Southwest African and the Norwegian passive mar- gins. These 3-D models differentiate various sedimentary, crustal, and mantle units and integrate different geophysi- cal data such as seismic observations and the gravity field. We extracted the temperature–depth distributions in 1 km intervals down to 6 km below the upper thermal boundary condition. The geothermal gradient was then calculated for these intervals between the upper thermal boundary condi- tion and the respective depth levels (1, 2, 3, 4, 5, and 6 km below the upper thermal boundary condition). According to our results, the geothermal gradient decreases with increas- ing depth and shows varying lateral trends and values for these two different margins. We compare the 3-D geologi- cal structural models and the geothermal gradient variations for both thermal models and show how radiogenic heat pro- duction, sediment insulating effect, and thermal lithosphere– asthenosphere boundary (LAB) depth influence the shallow thermal field pattern. The results indicate an ongoing process of oceanic mantle cooling at the young Norwegian margin compared with the old SW African passive margin that seems to be thermally equilibrated in the present day.…
Verfasserangaben: | Ershad GholamrezaieORCiDGND, Magdalena Scheck-WenderothORCiDGND, Judith SippelORCiDGND, Manfred StreckerORCiDGND |
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URN: | urn:nbn:de:kobv:517-opus4-418210 |
DOI: | https://doi.org/10.25932/publishup-41821 |
ISSN: | 1866-8372 |
Titel des übergeordneten Werks (Englisch): | Postprints der Universität Potsadm : Mathematisch-Naturwissenschaftliche Reihe |
Untertitel (Englisch): | the Southwest African and the Norwegian margins |
Schriftenreihe (Bandnummer): | Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe (621) |
Publikationstyp: | Postprint |
Sprache: | Englisch |
Datum der Erstveröffentlichung: | 19.02.2019 |
Erscheinungsjahr: | 2018 |
Veröffentlichende Institution: | Universität Potsdam |
Datum der Freischaltung: | 19.02.2019 |
Ausgabe: | 621 |
Seitenanzahl: | 20 |
Quelle: | Solid Earth 9 (2018), pp. 139–158 DOI 10.5194/se-9-139-2018 |
Organisationseinheiten: | Mathematisch-Naturwissenschaftliche Fakultät |
DDC-Klassifikation: | 5 Naturwissenschaften und Mathematik / 55 Geowissenschaften, Geologie / 550 Geowissenschaften |
Peer Review: | Referiert |
Publikationsweg: | Open Access |
Fördermittelquelle: | Copernicus |
Lizenz (Deutsch): | CC-BY - Namensnennung 4.0 International |