Curie Point Depth of the Island of Crete (Greece)

Abstract

—The aeromagnetic data of the island of Crete were inverted to produce Curie point estimates. The data were high-pass filtered to remove components arising from topography and magnetic core fields which were not adequately modeled by IGRF. The depth to the centroid, z ₀ , of the deepest distribution of the magnetic dipoles, was obtained by computing a least-squares fit to the lowest-fre quency segment of the azimuthally averaged log power spectrum. The depth to the top of the deepest crustal block was computed as the depth, z _t  , to the centroid of the second deepest distribution, using the second lowest-frequency segment of the spectrum. The depth to the bottom of the deepest dipoles, the inferred Curie point depth, is then z _b = 2z ₀−z _t  . The Curie depth estimates range between 24 and 28 km. This is in accordance with the depths inferred by extrapolating heat-flow values measured in boreholes.