By Therese from just below the bridge on Wednesday, September 22, 2004 - 06:56 pm:
I have some questions for Dr Nat or Cap Paul, or any other geologist out there. In the Keweenaw formation which is, if I have my story right, 1.1 billion-year-old sandstone, what are all the oval river-washed stones? Are they basalt? Little meteorites? Dinosaur gallstones? (Oh wait, there werent any dinosaurs yet, or anything else for that matter.) How old are they, and where did they come from to get buried in sand in a river? How wide was that river? Or were they washed into a shallow sea?
Come to think of it, where did the sand come from and what was it made of? Is it iron-rich quartz? And how did the sandstone keep from being sucked down and metamorphosed for over a billion years? Is it the oldest sedimentary rock on earth? (My grandpa was once the oldest sedentary man on earth, but that's another story.)
I ask because I am holding a chunk of the stuff gathered last weekend near Copper Harbor. And you know what makes me feel really weird? To loosen a stone and finally pull it free from its hollow in the sandstone, and realize that, for the first time in over a billion years, this stone is touched by sunlight. It's been in the dark for an unimaginable stretch of time, until I pull it out and hold it in my hand. When light last hit this stone, there was no life on earth, no amoebas, no trilobites, no worms, no insurance salemen, or any other lower life forms. I can't even imagine what this area looked like a billion years ago.
By I'M A MAN BUT I CAN CHANGE IF I HAVE TO ..I GUESS on Wednesday, September 22, 2004 - 07:15 pm:
http://redgreen.com/ RED RULES..
By