A lot of rockhounds don’t really have a concept of “deep time”. That's the time that has passed to form the fossils for sale here. There are a lot of “deep” subjects that most people also don’t get. “Deep Space” for example, or “Deep Thought” (the computer in The Hitchhiker's Guide to the Galaxy). I hope to add a little substance to those concepts here.
Consider “Deep Space”. The entertainment industry is in love with the idea of aliens from other planets (and the opposite - humans as aliens going to some other planet). The problem with that is “Deep Space” is much too far for anything from this planet to ever get there. (Except maybe a fossil. More on this in a few paragraphs.)
Alpha Centauri is the closest star to Earth. According to Space.com, “At a maximum speed of about 17,600 mph … it would take the space shuttle, for example, about 165,000 years to reach Alpha Centauri.” The Space.com site also considers progressively wilder ideas such as setting off nuclear bombs behind a space ship to propel it. But nothing that anybody has thought of will do it in less than a lifetime. And that’s for the closest star to Earth. Traveling to other galaxies … or even someplace in this galaxy … are like the Norse god Thor being somehow … “real”.
Oh! Wait! Today, they make movies about that too! … Well … Moving on …
The human mind finds it difficult to relate to the extremes that actually exist. Our point of view is just too limited to wrap around these ideas. The Harvard evolutionary biologist Stephen Jay Gould used the metaphor of mayflies discussing tadpoles in a swamp below them to explain why. Adult mayflies have a lifespan ranging from a few minutes to a few days. One mayfly is telling another one, “You can’t tell me that wiggly little thing will turn into a frog! I’ve been watching it for most of my life and it hasn’t changed at all!”
The deep time of fossils is one of those things that is hard to imagine. The Chicxulub meteor killed out dinosaurs … and most other things on Earth … 66 million years ago. So, all agate dinosaur bone fossils are older than that. They could date back more than 240 million years. But can you really hold a concept of that much time in your head? If we used a measure as long as a football field to represent the 66 million years since the dinosaurs died out, our own lifespan of about 75 years would be much smaller than the period at the end of this sentence in comparison – only four one-thousands of an inch. When I write that molecules of silica – SiO2 – replaced the organic molecules in the original dinosaur bone - one by one to form agate - there was plenty of time for that to happen.
But deep time gets much deeper than that. My dad and other rockhounds used to collect Utah red horn coral from layers of the Earth pushed high in the Uinta Mountains that were once a shallow sea bottom. (See: Utah Red Horn Coral ) These beautifully preserved fossils were living coral perhaps 450 million years ago – 6 times older than the dinosaurs. Our insignificant 75 year life span is looking smaller and smaller.
And then there is Mary Ellen jasper, a stromatolite fossil that lived in even earlier shallow seas. The living organisms that were replaced with silica to create these fossils lived 2.1 billion years ago. That’s 28 million human lifetimes. If humans were alive back then (they most assuredly were not), then they would be your great, great … 70 million “greats” … grandparents. More “greats” than years since the dinosaurs died.
Here's another Deep Time example … one you might not have heard about. There are places in the Atacama Desert in Chile where “rubbing boulders” can be found. These boulders are in groups and appear eroded and rounded. There’s no way water could have been involved. The Atacama has been dry for around 11 or 12 million years. The best explanation is that the boulders tumbled from cliffs and traveled across the gently sloping desert urged along by shaking from earthquakes – estimated at four per year in this “Ring of Fire” region. And when they have bunched up into groups, they eroded by rubbing up against each other during earthquakes. Scientists think that these rocks have experienced “50,000 to 100,000 hours of bumping and grinding” this way. They did all this in only ten percent of the time since the dinosaurs died. See The Strange Rubbing Boulders of the Atacama for more details.
The article calls it “the worlds largest natural rock tumbler”. But it works at an incomprehensible slow speed, especially compared to the three or four months it might take your lapidary shop tumbler to polish some of my dad’s agate. See my Regular Bag Rocks if you want a bag of agate and jasper just right for your three pound rock tumbler.
After a while, the mind boggles. …. boggle, boggle, boggle …
I am thoroughly boggled. Thank you.