Where would I hide a Jurassic time capsule?
If you could go back to the Jurassic period with a camera and a way to store data for us to later find, how would you plant that time capsule for geologists and paleontologists to dig up today? Where would be a good place to sequester it. Where's the best place to put something so it'll stay around for a long time?
Will - Well, I mean, I certainly wouldn't choose the Jurassic if I had a choice, I don't think I'd last very long.
Chris - But I think that's the point he's making is he wants pictures of dinosaurs?
Will - Well, I'd home in on the Goldilocks zone. I'd certainly choose continental crust. We have two types of crust, continental crust, and oceanic. Oceanic is less buoyant, it's denser. So when the two meet, it's the oceanic crust that subducts. So whilst my camera might be waterproof, it probably can't survive subducting to earth's mantle. It's probably a bit too hot for it. So I'd choose land. Maybe I'd choose a mountain. Well, mountains erode as we said earlier. I wouldn't know where my camera would end up. So I'd probably be heading towards Earth's more lowland environments. I'll introduce a term here: sedimentary basin. These are essentially depressions in earth's landscape where sedimentary rocks, sedimentary piles, can build up, they can accrue. So I'd find somewhere that was actively depositing such that my camera has a chance of making it into the record. I'd need it not to be connected to the oceans. If I put it in a river basin, long after I've been eaten by the T-Rex, the river shifts, reworks where my camera was and takes it off to the ocean and abducts it to the mantle, that's not doing us any good. I'd probably try and find, a lake, ideally a hydrologically closed lake, a lake that's not connected to the ocean in any way, but sort of disconnected by some sort of resistant topographic upland, something with high preservation potential, this sort of very low energy environment with no chance of my camera sort of heading out anywhere. This is the case where my sediment could sort of gradually over time build up around it and preserve it. But we've still got a problem then: we might preserve the camera, but we still need to expose it in the present day for a modern geologist who is wandering around. Where geological outcrops exist, it's very stochastic. It's very random. We need a road cut in a nice area or a beach where waves are bashed and exposed our rock.
Chris - When you said exposure I was thinking of camera exposure, It can be digital, you're all right. But I guess what you mean is it's got to come to the surface in some way so that someone like you can stumble on it?
Will - Absolutely. And the chances of that happening are pretty minute. I think if all these dreams did come true and I was the geologist that found the camera, I'd be more interested in how the time machine was invented.
Chris - The physicist in you would kick in. Surely a really good answer to this question is you would go and find where all the fossils are and go back to where there's a really rich source of fossils and put it where those fossils are going to have come from, because there's lots of likelihood someone will go and dig in that area, and that's an area that's going to be preserved from that time period.
Will - That's true. I guess I'd have to also then trust the paleo continental reconstructions and try and retrace my geological footsteps.
Chris - But you guys know what you're doing, don't you?
Will - I trust my peers. I don't do the pale continental reconstructions myself.