I was lucky enough that Felix posted his hint (
WoGE #228) just before my lunch-hour, which stopped my futile search for diamond mines (don't ask me why).
Find the location of the picture on GoogleEarth (latitude/longitude) and describe the geology of the place (I have a particular feature in mind). There is no Schott rule, as I think it may be hard to find, but I'm prepared to be proved wrong...
If you do not know what this is all about read
this.
Felix has won!
My take on the Geology below.
The ghostly wiggly lines are called roddons (see Wikipedia entry). They are indeed silt/mud surrounded by darker peat and represent an old (but not very old) set of drainage channels over the area.
Since they were formed, the area has been drained (hence the regular shaped fields and drainage ditches). Through a process of drying out and other things the peat has shrunk but the silt channels have not. This means they remain as raised areas and are sometimes the site of villages or roads. The whole area is now below sea-level.
Note the regular fields: these areas were 'enclosed' c. 0.3ka which forms a landscape more like the Netherlands than the rest of England. Also note that the range of photos in the bottom left don't show them; they are subtle features not visible under a healthy crop of vegetation.
A final whimsical note, a less interesting section in Wikipedia debates whether roddon should be spelt rodham, which is the US Secretary of State's middle name (or is it maiden name?). Given her daughter has the same name as a part of London, I wonder if there is a traditional of geographical names in her family.