The e-mail address for Nathan Bridges was inadvertently omitted when this message was originally posted, so we are repeating it here. Dear Volcanological Community, There is currently a discussion among the remaining few of us who study Venus' geology as to the origin of polygonal patterns seen there. In some cases they appear confined to the boundaries of what are interpreted as individual lava flows, whereas in other examples they are more regional.
Polygonal patterns are a common result of contractional cooling of lava flows and welded tuffs.
However, the perception of myself and others is that the scale of terrestrial features is generally at the meter scale, much smaller than those on Venus. My question is whether this is truly the case. Can surface structures such as polygons be seen in field exposures of such old flows. Any assistance to this question would be greatly appreciated.