Tectonic implications of Mars crustal magnetism.

Mars currently has no global magnetic field of internal origin but must have had one in the past, when the crust acquired intense magnetization, presumably by cooling in the presence of an Earth-like magnetic field (thermoremanent magnetization). A new map of the magnetic field of Mars, compiled by using measurements acquired at an approximately 400-km mapping altitude by the Mars Global Surveyor spacecraft, is presented here. The increased spatial resolution and sensitivity of this map provide new insight into the origin and evolution of the Mars crust. Variations in the crustal magnetic field appear in association with major faults, some previously identified in imagery and topography (Cerberus Rupes and Valles Marineris). Two parallel great faults are identified in Terra Meridiani by offset magnetic field contours. They appear similar to transform faults that occur in oceanic crust on Earth, and support the notion that the Mars crust formed during an early era of plate tectonics.

[1]  David E. Smith,et al.  The global topography of Mars and implications for surface evolution. , 1999, Science.

[2]  J. Sauvaud,et al.  Mars Observer magnetic fields investigation , 1992 .

[3]  H. Masursky,et al.  Geology of the Valles Marineris: First analysis of imaging from the Viking 1 Orbiter Primary Mission , 1977 .

[4]  W. C. Pitman,et al.  Magnetic Anomalies over the Pacific-Antarctic Ridge , 1966, Science.

[5]  Jack Oliver,et al.  Seismology and the new global tectonics , 1968 .

[6]  J. Connerney,et al.  Magnetic field of Mars: Summary of results from the aerobraking and mapping orbits , 2001 .

[7]  Ness,et al.  Magnetic lineations in the ancient crust of mars , 1999, Science.

[8]  J. Tuzo Wilson.  A possible origin of the Hawaiian Islands , 1963 .

[9]  W. Hartmann.  Martian surface and crust: Review and synthesis , 1973 .

[10]  J. Wilson,et al.  A New Class of Faults and their Bearing on Continental Drift , 1965, Nature.

[11]  Norman H. Sleep,et al.  Hotspots and Mantle Plumes' Some Phenomenology , 1990 .

[12]  C. Laj,et al.  Magnetic Anomalies Over Oceanic Ridges , 1963, Nature.

[13]  G. Schubert,et al.  Mars Crustal Magnetism , 2004 .

[14]  Ness,et al.  Global distribution of crustal magnetization discovered by the mars global surveyor MAG/ER experiment , 1999, Science.

[15]  R. Phillips,et al.  Thermal and crustal evolution of Mars , 2002 .

[16]  H. Frey.  Martian canyons and African rifts: Structural comparisons and implications , 1979 .

[17]  M. Purucker,et al.  Satellite magnetic anomalies related to seafloor spreading in the South Atlantic Ocean , 2000 .

[18]  W. J. Morgan,et al.  Rises, trenches, great faults, and crustal blocks , 1968 .

[19]  N. Sleep.  Martian plate tectonics , 1994 .

[20]  R. Blakely.  Potential theory in gravity and magnetic applications , 1996 .

[21]  L. Rosenhead.  Conduction of Heat in Solids , 1947, Nature.

[22]  F. J. Vine,et al.  Spreading of the Ocean Floor: New Evidence , 1966, Science.

[23]  Ronald Greeley,et al.  Volcanism on Mars , 1981 .

[24]  F. Nimmo,et al.  Influence of early plate tectonics on the thermal evolution and magnetic field of Mars , 2000 .

[25]  Kenneth L. Tanaka.  The stratigraphy of Mars , 1986 .

[26]  David J. Dunlop,et al.  Rock Magnetism: Fundamentals and Frontiers , 1997 .

[27]  D. Mitchell,et al.  The global magnetic field of Mars and implications for crustal evolution , 2001 .

[28]  J. Cain,et al.  External fields on the nightside of Mars at Mars Global Surveyor mapping altitudes , 2005 .

[29]  Jeffrey B. Plescia,et al.  Cerberus Fossae, Elysium, Mars: a source for lava and water , 2003 .

[30]  D. Turcotte.  Are transform faults thermal contraction cracks , 1974 .