One of the great unconformities demonstrating geological time
Having belatedly discovered The Earth Science Picture of the Day website (it has been going since September 2000; as long as Earth Pages!) I thought readers of EPN might like the aesthetic boost that it provides. So, on the last day of the month I intend to insert a link to what I think is the best of those contributed to EPOD over the previous 4 weeks or so.
EPOD has a vast archive of contributions and each one has a brief description and links to other visual resources.