The creation of the Wannon Falls can be traced back to when a
volcano erupted to the southeast between one and two million years
ago.
The lava flowed down into the natural valleys known as the
Grange Burn and the Wannon Valley and formed a hard cap of volcanic
rock over a layer of softer rock. The churning action of the water
pooled at the bottom of the falls continually erodes this soft
layer, causing pieces of the volcanic layer above to break away,
and the waterfall to retreat upstream.
The result is the appearance of the trail of rocky carnage that
you see downstream while standing at the photo point (S37 40.567
E141 50.496). It has also resulted in the valley being deeper than
it was prior to the volcanic eruption.
To log a find on this Earthcache, you must email us the answers
to the following questions from the information board at the given
coordinates, and post a photo of your GPSr at the photo point in
your log (no answers in logs please):
1. What type of sediment is the softer layer comprised
of?
2. What type of rock is the top volcanic layer made up
of?
3. How far undercut are the Falls?
4. How far have the falls retreated since they were
formed?
As per Earthcache guidelines, logs will be
deleted if answers to the above questions are not emailed. You may
log a find before receiving information, as long as the email has
been sent.
While visiting this Earthcache, you should also visit the
nearby traditional cache,
GCGK3X Plenty by maccamob.