Tectonic landforms
Densely lineated plains · Gridded plains
Densely lineated plains
Plains densely cut by lineaments – linear features of undetermined type (see the plate).
Lineaments a few hundred metres wide and a few tens of kilometres long run parallel to one another, almost merging, in patches on these deformed plains. Each patch is several tens of kilometres wide. The wider lineaments look like faults. Densely lineated plains are older than wrinkle ridge plains and shield plains. They make up only one and a half per cent of the surface of Venus.
Gridded plains
Fracture systems meet at right angles (see the figure).
These are groups of thin, parallel, straight, diverging lineaments that cross one another. If they appear only in a thin surface layer, they may result from regional stress in the brittle crust or from thermal stress caused by climate change. If their traces reach deep, dyke swarms may be involved, or they may mark where fracture systems meet (Banerdt and Sammis 1992). The type example is in Guinevere Planitia.
