Mapping the thermal structure of southern Africa from Curie depth estimates based on wavelet analysis of magnetic data with uncertainties
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• Mohamed Sobh,
• Christian Gerhards,
• Hans-Jürgen Götze,
Mohamed Sobh
Institute of Geophysics and Geoinformatics, TU Bergakademie Freiberg, Germany

Corresponding Author:mohamed.sobh@geophysik.tu-freiberg.de

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Christian Gerhards
Institute of Geophysics and Geoinformatics
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Hans-Jürgen Götze
Institute of Geosciences, Christian-Albrechts-University Kiel
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Surface heat flow provides essential information on the thermal state and thickness of the lithosphere. Southern Africa is a mosaic of the best-preserved and exposed crustal blocks, assembled in the early late Archean and then modified by a series of major tectono-thermal events, both of Precambrian and Phanerozoic. Understanding the thermal and compositional structure of the southern African lithosphere provides crucial information for the actual causes, processes of lithospheric stability, and modification. Temperature plays a major role in the distribution of the long-wavelength crustal magnetic anomalies. Curie depth, interpreted as the depth to $580^{\circ}$C, provides a valuable constraint on the thermal structure of the lithosphere. Due to the sparse distribution of surface heat flow data, we examine the degree to which the thermal structure of the crust can be constrained from the Curie depth in southern Africa. The Curie depth is estimated from magnetic anomaly data using spectral methods in combination wavelet analysis; a Bayesian approach is applied to address the uncertainty. Subsequently, the obtained Curie depth is used to estimate the surface heat flow, and the outcome is compared to available heat flow measurements. Unlike other cratonic regions, the shallowest Curie depth and low effective elastic thickness values observed over the Kaapvaal Craton suggest thermal reworking of the cratonic lithosphere in this region.