Earth Planets Space, Vol. 57 (No. 8), pp. 717-726, 2005
Hyung Rae Kim1, Ralph R. B. von Frese2, Alexander V. Golynsky3, Patrick T. Taylor4, and Jeong Woo Kim5
1Goddard Earth Science and Technology, University of Maryland, Baltimore County at Planetary Geodynamics Lab, NASA/GSFC, Greenbelt, Maryland, USA
2Department of Geological Sciences, The Ohio State University, Columbus, Ohio, USA
3VNII Okeangeologia, St. Petersburg, Russia
4Code 698, Planetary Geodynamics Lab, NASA/GSFC, Greenbelt, Maryland, USA
5Department of Geoinformatic Engineering, Sejong University, Seoul, South Korea
(Received February 20, 2004; Revised April 12, 2005; Accepted May 1, 2005)
We produced a crustal magnetization model for the Maud Rise in the southwest Indian Ocean off the coast of East Antarctica using magnetic observations from the Ørsted satellite and near-surface surveys complied by the Antarctic Digital Magnetic Anomaly Project (ADMAP). Joint inversion of the two anomaly fields suggests that the magnetic effects due to crustal thickness variations and remanence involving the normal polarity Cretaceous Quiet Zone (KQZ) dominate at satellite altitude (~700 km). The crustal thickness effects were modeled in the Ørsted data using crustal thickness variations derived from satellite altitude gravity data. Modeling of the residual Ørsted and near-surface magnetic anomalies supports extending the KQZ eastwards to the Astrid Ridge. The remaining near-surface anomalies involve crustal features with relatively high frequency effects that are strongly attenuated at satellite altitudes. The crustal modeling can be extended by the satellite magnetic anomalies across the Indian Ocean Ridge for insight on the crustal properties of the conjugate Agulhas Plateau. The modeling supports the Jurassic reconstruction of Gondwana when the African Limpopo-Zambezi and East Antarctic Princess Astrid coasts were connected as part of a relatively demagnetized crustal block.
Key words: Maud Rise, Magnetic anomaly, Antarctic geology, Aeromagnetic data, Orsted, tectonic reconstruc-tions.