JET PROPULSION LABORATORY
CALIFORNIA INSTITUTE OF TECHNOLOGY
NATIONAL AERONAUTICS AND SPACE ADMINISTRATION
PASADENA, CALIF. 91109
 
PHOTO CAPTION                                MAGELLAN
                                             P-37788  MGN-36
                                             3/5/91
 
 
     This Magellan image shows part the interior of Ovda Regio, one
of the large highlands ringing the equator of Venus.  Several
tectonic events formed this complex block-fractured terrain.  An
underlying fabric of ridges and valleys strikes NE-SW.  These
ridges are spaced 10-20 kilometers (6-12 miles) apart and may have
been caused by shortening of the crust at right angles to this
trend.  These structures are cut by throughgoing extension
fractures trending NW-SE, suggesting a later episode of NE-SW
extension.  Lastly, the largest valleys, particularly the 20
kilometer (12 mile)-wide one extending across the image, were
filled with dark material, probably lava.  The complex internal
fabric of Ovda Regio attests to a long history of tectonic
deformation.  This image, centered approximately at 1 S 81 E,
measures 225 kilometers (140 miles) by 150 kilometers (90 miles)
and was acquired by Magellan in November 1990.