Sunday, 9 October 2011
On Jurassic Coast
Our home --- for now
Our annual attempt to cheat Scottish weather --- grab some extra summer days that, under the rules of the game, we're not entitled to, sent us to the Jurassic Coast, Southern England. Standing below the red cliffs (Triassic --- having formed over 200 million years ago) you sense their immense age.
My geologist's eye immediately focused on the rocks' internal structure: ripples and waves left in the sand. Vast rivers used to flow there, greater than any river system that survives these days. Over millions of years they deposited the sand, moved it about. The climate was arid, about 5 degrees hotter than today. Imagine the Arabian desert criss-crossed with rivers that flooded, receded, dried out for some years, then flooded again. That was the land.
Note that the shallower layers cut down into older ones
the way a fast flowing river cuts into its banks
Back to today's beach, I'm among a sea of rounded pebbles, the water transparent green, as the Adriatic. And a much cooler climate. It's a clean beach without any shells. Some washed up kelp is the only living matter.
Farther East we walked on a cobble beach under the Jurassic black shale, once a shallow sea teeming with swimming dinosaurs. We could tell that it is prime fossil territory because people everywhere were digging at the cliff with small hammers.
An old woman, easily in her seventies, carrying a bag leaned on her stick. With one end she poked at the rocks. She told us where to look for fossils --- under a light marker called the "ice age marker". That's where she uncovered vertebrae bones of a Pleisaurus. She almost had all the pieces. I happened upon a vertebra fragment, now filled in with silica. Holding something so ancient sent the mind reeling back in time, in a real sense that no Spielberg movie, or geologic textbook could accomplish.
I was back in an alien landscape, in days when we not only did not exist, but nature hadn't conceived that we might one day be born. That we would one day dominate the Earth.