This Magellan mosaic shows a portion of the Lada Terra highlands on Venus. The image, centered near 65 degrees south latitude and 14 degrees east longitude, covers an area about 1900 kilometers (1178 miles) north to south by about 600 kilometers (372 miles) east to west. The large, complex bright terrain trending from the lower left to the upper right of the image is tessera terrain, characterized by multiple sets of complexly intersecting ridges and troughs. This region of tessera has been heavily disrupted by crustal stresses and degraded by later lava flows. The dark smooth valleys extending to the northeast area about 15-50 kilometers (9-31 miles) across and have been filled by lavas. Near the center of the image within the tessera are two small semicircular depressions, separated by about 300 kilometers (186 miles), that may be ancient impact craters heavily modified by subsequent tessera disruption. To the north and south of the tessera lava flows have formed extensive plains regions, flooding the lower elevations of the edges of Lada Terra. At the top of the image is the southern rim of Eithinoha corona, a 500 kilometer (310 mile wide circular structure surrounded by concentric ridges thought to have formed as hot magma within the Venus crust migrated toward the surface, bowing up the crust and producing a smooth interior flooded by volcanic deposits and a ridged boundary. Large cracks or rifts are seen extending around the western edge of the corona and to the south, probably a direct result of the crustal stresses associated with the formation of the corona.
