New aerogeophysical view of the Antarctic Peninsula: more pieces, less puzzle

• Published in: Geophysical Research Letters
• Main Authors: Ferraccioli, F., Jones, P.C., Vaughan, A.P.M., Leat, P.T., Dean, A.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: American Geophysical Union 2006
• Subjects: Earth Sciences; Antarctic; The Antarctic; Antarctic Peninsula; Baja; Pacific; Palmer Land; Antarc*
• Online Access: http://nora.nerc.ac.uk/id/eprint/48/

New airborne geophysical data reveal subglacial imprints of crustal growth of the Antarctic Peninsula by Mesozoic arc magmatism and terrane accretion along the paleo-Pacific margin of Gondwana. Potential field signatures indicate that the Antarctic Peninsula batholith is a composite magmatic arc terrane comprising two distinct arcs, separated by a >1500 km-long suture zone, similar to the Peninsular Ranges batholith in southern and Baja California. Aeromagnetic, aerogravity and geological data suggest that a mafic Early Cretaceous western arc was juxtaposed against a more felsic eastern arc which, in mid-Cretaceous times, was intruded by highly magnetic tonalitic/granodioritic plutons of island arc affinity. Suturing of the two arcs against the Gondwana margin caused the mid-Cretaceous Palmer Land orogenic event. Convergence and suturing may have been driven by two subduction zones or, alternatively, by a decrease in slab dip, leading to an inboard migration of the arc, as in California.