Curie point depth based on spectrum analysis of the magnetic anomaly data in East and Southeast Asia

The bottom of the magnetized crust determined from the spectral analysis of residual magnetic anomalies is generally interpreted as the level of the C urie point isotherm. A method to estimate the depth extent of magnetic sour ces (Curie point depth analysis) was applied to the magnetic anomalies of E ast and Southeast Asia. Although the geologic and physiographic complexitie s of this area constrain the method, certain correlations between the Curie point depths and heat flow data are apparent and the Curie point depths ar e consistent with the tectonic settings. Shallow basal depths of magnetic s ources that extend in back-are regions correspond to high heat flow values. The correspondence of deep basal depths with low heat flow values along th e trench axis suggests that they are both related to the subducting plate. We also estimate the Curie point depths from heat flow data using a one-dim ensional heat conductive transport model. Good agreement between the Curie point depths derived from heat flow data and magnetic data suggests that th e Curie point depth analysis is useful to estimate the regional thermal str ucture. (C) 1999 Elsevier Science B.V. All rights reserved.