Randall Carlson

But so they analyzed it to try to figure out how much time elapsed. you know, over the succession of this stuff. And that's when they discovered the iridium spike. And then they thought, where does, it was like 100 times or more than the background account of iridium. And iridium is rare in the Earth's crust because it's a siderophile. It loves iron.

But so they analyzed it to try to figure out how much time elapsed. you know, over the succession of this stuff. And that's when they discovered the iridium spike. And then they thought, where does, it was like 100 times or more than the background account of iridium. And iridium is rare in the Earth's crust because it's a siderophile. It loves iron.

But so they analyzed it to try to figure out how much time elapsed. you know, over the succession of this stuff. And that's when they discovered the iridium spike. And then they thought, where does, it was like 100 times or more than the background account of iridium. And iridium is rare in the Earth's crust because it's a siderophile. It loves iron.

So the assumption was is that the absence of iridium in the Earth's crust was because in the early days of the Earth's formation, Yeah, there you go, right there. There it is, the Paleocene. They've changed the names a little bit. So you've got the Cretaceous, which was the final period of the Mesozoic or era of middle life.

So the assumption was is that the absence of iridium in the Earth's crust was because in the early days of the Earth's formation, Yeah, there you go, right there. There it is, the Paleocene. They've changed the names a little bit. So you've got the Cretaceous, which was the final period of the Mesozoic or era of middle life.

So the assumption was is that the absence of iridium in the Earth's crust was because in the early days of the Earth's formation, Yeah, there you go, right there. There it is, the Paleocene. They've changed the names a little bit. So you've got the Cretaceous, which was the final period of the Mesozoic or era of middle life.

Then you have the Paleocene, which is the first epoch of the Cenozoic, which is recent life. Separating them is that iridium layer right there. And so what they did was they weren't looking for the iridium layer, but they found the iridium layer when they were analyzing, trying to figure out how much time had elapsed.

Then you have the Paleocene, which is the first epoch of the Cenozoic, which is recent life. Separating them is that iridium layer right there. And so what they did was they weren't looking for the iridium layer, but they found the iridium layer when they were analyzing, trying to figure out how much time had elapsed.

Then you have the Paleocene, which is the first epoch of the Cenozoic, which is recent life. Separating them is that iridium layer right there. And so what they did was they weren't looking for the iridium layer, but they found the iridium layer when they were analyzing, trying to figure out how much time had elapsed.

So then they contact colleagues, I think Denmark, New Zealand, and one or two other places. and said, go back and look at that transition of Cretaceous to Tertiary and see if there's iridium enhancement. And everywhere they looked, there was. And it quickly became, within a couple of years, apparent that the whole world had apparently been dusted in iridium.

So then they contact colleagues, I think Denmark, New Zealand, and one or two other places. and said, go back and look at that transition of Cretaceous to Tertiary and see if there's iridium enhancement. And everywhere they looked, there was. And it quickly became, within a couple of years, apparent that the whole world had apparently been dusted in iridium.

So then they contact colleagues, I think Denmark, New Zealand, and one or two other places. and said, go back and look at that transition of Cretaceous to Tertiary and see if there's iridium enhancement. And everywhere they looked, there was. And it quickly became, within a couple of years, apparent that the whole world had apparently been dusted in iridium.

Now, I was saying that iridium is a siderophile, so the idea was that in the early days of the molten earth, iridium bonded to the iron, and iron being dense, it subsided deep into the mantle and took the iridium with it, leaving the Earth's crust deficient in iridium. But iridium is found in abundance in meteorites.

Now, I was saying that iridium is a siderophile, so the idea was that in the early days of the molten earth, iridium bonded to the iron, and iron being dense, it subsided deep into the mantle and took the iridium with it, leaving the Earth's crust deficient in iridium. But iridium is found in abundance in meteorites.

Now, I was saying that iridium is a siderophile, so the idea was that in the early days of the molten earth, iridium bonded to the iron, and iron being dense, it subsided deep into the mantle and took the iridium with it, leaving the Earth's crust deficient in iridium. But iridium is found in abundance in meteorites.

And so they then, from spectral analysis of meteorites and actual samples of meteorites, they had a pretty good idea of the... the percentage of iridium that would be, as I say, in a carbonaceous chondritic meteorite. And from that, they then said, well, if the whole world got dusted with iridium at this concentration, then how big of an asteroid would it take

And so they then, from spectral analysis of meteorites and actual samples of meteorites, they had a pretty good idea of the... the percentage of iridium that would be, as I say, in a carbonaceous chondritic meteorite. And from that, they then said, well, if the whole world got dusted with iridium at this concentration, then how big of an asteroid would it take

And so they then, from spectral analysis of meteorites and actual samples of meteorites, they had a pretty good idea of the... the percentage of iridium that would be, as I say, in a carbonaceous chondritic meteorite. And from that, they then said, well, if the whole world got dusted with iridium at this concentration, then how big of an asteroid would it take

to deposit, to carry that much iridium into the Earth's, you know, into the Terra sphere and deposit it. And their calculations led to an asteroid about six miles in diameter, which interestingly was the same size as that speculated by Otto Muck for the impact at the, would have been the Younger Dryas, roughly boundary in there. Now, that didn't, I don't think that happened. Why?

to deposit, to carry that much iridium into the Earth's, you know, into the Terra sphere and deposit it. And their calculations led to an asteroid about six miles in diameter, which interestingly was the same size as that speculated by Otto Muck for the impact at the, would have been the Younger Dryas, roughly boundary in there. Now, that didn't, I don't think that happened. Why?