Abstract

The bottom of the magnetized crust determined from the spectral analysis of residual magnetic anomalies is generally interpreted as the level of the Curie point isotherm. A method to estimate the depth extent of magnetic sources was applied to the magnetic anomalies of East and Southeast Asia. Despite the geologic and physiographic complexities of this area which constrains the method used in this study, our results of depth extent of magnetic sources and the Curie point depth estimates are consistent with tectonic settings. Certain correlations between the basal depths of magnetic sources and heat flow measurements are apparent and suggest that undulations in basal depths of magnetic sources are related in part to undulations in the Curie point isotherm. For example, a shallow basal depth zone extends in the back arc region in which the heat flow is relatively high. The correspondence of deep basal depths with low heat flow values along the trench axis suggests that they are both related to the subducting plate. An area of shallow basal depth of magnetic sources in the center of the South China Sea corresponds to an area of high conductive heat flow and indicates a shallow depth to the Curie point isotherm in this region. Based on compilation of our results and previous studies, it is shown that the Curie point depths are shallower than about 10km at volcanic and geothermal areas, 15-25km at island arcs and back-arc rifts, deeper than 20km at continents, and deeper than 30km at trenches. We also estimate the Curie point depths from heat now data using a one-dimensional heat conductive transport modeL Good agreement between the Curie point depths derived from heat now data and magnetic data suggests that the pattern of the Curie point depths is useful as one of indices of the thermal structures.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.