Curie Point Depth Distribution in the Tibetan Plateau Based on Wavelet Analysis and Bayesian Inversion of Newly Compiled Aeromagnetic Anomaly Data

Abstract

The Tibetan Plateau and its surrounding regions are characterized by pronounced structural complexity and active tectonics, yet a high‐resolution map of Curie point depth (CPD) remains lacking. The CPD is primarily determined from aeromagnetic or satellite magnetic data in the literature. However, the long‐wavelength components of aeromagnetic anomaly data are often unreliable. Therefore, the 2D revised spherical cap harmonic analysis method was employed to extract unreliable long‐wavelength signals of aeromagnetic anomalies and to construct a new data compilation via incorporating the LCS‐1 model. Furthermore, an advanced approach combining wavelet analysis with the Bayesian method was applied to determine the CPD variations in the spectral domain. During the inversion, we considered whether to fix the sedimentary thickness and tested different fractal parameters, and then generated several CPD models. Finally, through a comprehensive analysis of geological and thermal structures, recommendations for the optimal CPD model were provided. Compared with other CPD results, the new CPD distribution shows consistent regional variations, with greater detail and reliability in the western Tibetan Plateau. The results show that the CPD exhibits significant lateral variations. The CPD in sedimentary Basins is relatively deeper, whereas in the Qiangtang and Lhasa blocks it is shallower, which agrees well with the variations of effective elastic thickness. The prominent shallow CPD branches in the eastern plateau coincide with crustal flow directions proposed previously. Despite existing uncertainty in absolute values, the relative CPD variation is robust and valuable for geologic, geothermal and geodynamic interpretations in the Tibetan Plateau.