I’m a long way from Jokers Hill at the moment, staring out
at the Gulf of Mexico from a condo in Indian Shores, Florida. The morning has
opened with cloud but it’s warm, people are walking in shorts. The waves wash
in over and over again and their sound cancels the traffic from Gulf Boulevard, except for the occasional heavy truck.
I walked on the beach a little while ago
myself, filling my sandals with sand that’s surprisingly soft, and found myself
wondering just what rocks have been ground down to form it. I wish I knew more
geography and geology.
As I walked I took photographs, picked up a shell here
and there, watched the Ruddy turnstones busy at the waterline or feeding on the
remnants of a shelled creature.
KSR hosts a Naturalists Training Course and at the end of January I joined it for the class on geology. (If you're curious about it check out this link: https://ksr.utoronto.ca/naturalistCourse)
Among the things I learned was that the
Canadian Shield—a feature I’ve known about for as long as I can remember, and
one that seems to be part of the Canadian identity, at least for my
generation—is part of a much larger formation called the North American Craton
that is the core of North America. If I understand it correctly, it also links
up to Greenland and the Hebrides in some way—so that it’s actually reasonable
for the Appalachian Trail folks to be working on extensions of the
International Trail in Europe. (More about that, perhaps, another time.)
Here’s a link to an image of the Craton with information
about it: http://www.mnh.si.edu/earth/text/4_1_3_1.html
As you can see, Florida does not rest on the Craton. I’ve
discovered it’s a large plateau formed by a combination of volcanic activity
and marine sedimentation, but I don’t have that formation clear in mind yet,
and since my knowledge of geology is so vague I can’t say what the sands here have come from. Clearly I need to work on geological literacy.
But even without that it’s fascinating to
walk the beaches and look at what the sea has tossed ashore.
above: horseshoe crab and ? ... left: a sea urchin
Then there are the grotesque finds:
I think this is some sort of sponge, but I don't know that for sure ...
