We Finally Know How Much the Dino-Killing Asteroid Reshaped Earth

Smithsonian ^ | 2/25/2016 | Jane Palmer

[JimSEA]

More than 65 million years ago, a six-mile wide asteroid smashed into Mexico's Yucatán peninsula, triggering earthquakes, tsunamis and an explosion of debris that blanketed the Earth in layers of dust and sediment.

Now analysis of commercial oil drilling data—denied to the academic community until recently—offers the first detailed look at how the Chicxulub impact reshaped the Gulf of Mexico. Figuring out what happened after these types of impacts gives researchers a better idea of how they redistribute geological material around the world. It also gives scientists an idea of what to expect if another such impact were to occur now.

The Chicxulub impact, which wiped out large dinosaurs and giant marine reptiles, created a global layer of debris that is now part of the geologic record. Geologists refer to this layer as the Cretaceous–Paleogene boundary, because it marks the switch between these two geologic time periods.

Read more: http://www.smithsonianmag.com/science-nature/we-finally-know-how-much-dino-killing-asteroid-reshaped-earth-180958222/#clK5ID5fmjUoGgkF.99 Give the gift of Smithsonian magazine for only $12! http://bit.ly/1cGUiGv Follow us: @SmithsonianMag on Twitter

[JimRed]

Or whatever caused Venus to virtually halt rotation and spin backwards.

Worlds In Collision (Immanuel Velikovsky, about 1950) presents an interesting theory about that which has not yet been refuted (or proven).

[JimRed]

Some scientists estimate such an impact probably turned the sky pitch black for at least a decade.

Some "scientists" also estimate that if we don't give them grants from our tax money to study the "problem" we're all gonna be roasted alive and drowned in a rising sea.

[Verginius Rufus]

The Chicxulub crater...the oldest disaster that can be blamed on George W. Bush.

[Bethaneidh]

I have heard the layer "evidence" could be compromised by hot mut sorting particulate by specific gravity, not time. So investigators could sometimes be just guessing. ☺

[Bethaneidh]

Uh, sorry, NO doggie ping MUD.

[txhurl]

Asteroids get slung out of the Oort Cloud in swarms. Relatively speaking. There’s only a 5% chance, but the big one may have camoflaged the destruction of an earlier, smaller one in the GOM, with some oceanic ceaters yet to be discovered. I’m always pleased to hear of any species surviving impact. Do you think the volcanoes are responsible for the ELE that snatched our dinos?

[Some Fat Guy in L.A.]

So we can blame the asteroid for Austin?

Yep - the Mexicans kicked it out and it migrated across the open border.

[Maelstrom]

Oooo....leaves me shaking too.

[BroJoeK]

qam1: "* There was a species of Hardosaur that was alive at the K-T Boundary, but the Asteroid or whatever didn't kill it and it lived on another 700,000 years."

Maybe, maybe not:

"There is possible evidence of a Dead Clade Walking: in 2001, evidence was presented that pollen samples recovered near a fossilized hadrosaur femur recovered in the Ojo Alamo Sandstone at the San Juan River indicate that the animal lived during the Paleogene Period, approximately 64.5 million years ago.[2]
Direct dating of bone has also been used to present an age of 64.8 ± 0.9 million years for one specimen.[3]

"Many scientists, however, dismiss the 'Paleocene non-avian dinosaurs' as reworked, that is, washed out of their original locations and then reburied in much later sediments.[4]
A compelling argument against reworking would be a complete or at least associated skeleton (e.g. more than one bone from the same individual) found above the K-Pg boundary.
As yet no such finds have been reported."

Bottom line: examples are too limited to draw broad conclusions.
The most likely explanation is "reworking".

[SunkenCiv]

Note: this topic is from 3/22/2016. Thanks JimSEA.

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[SunkenCiv]

Note: this topic is from 3/22/2016. Thanks JimSEA.

[null and void]

Such a disaster causing such a mass die off should leave a sediment layer...

That's the iridium rich clay layer precisely at the K-T boundary. World wide.

...full of fossils.

Dino and massive numbers of foraminifer under it, NOTHING above it.

The strike pumped so much sulfur (formed sulfuric acid), so many oxides of nitrogen (formed nitric acid) and so much eeeeeevil See Oh Too (carbonic acid) that the acid rain conditions prevented anything that wasn't burned to ash from forming fossils.

[null and void]

Imaging a shallow sea strike, forming a mere 200 km diameter crater. Sea water pours into a 120 mile wide white hot crater. That forms a steam powered rocket engine blasting water and air into space, only some of which makes its way back to earth.

I bet the atmospheric pressure dropped by half. Pretty hard on anything that wasn’t used to living in oxygen depleted deep burrows...

[MileHi]

It also gives scientists an idea of what to expect if another such impact were to occur now.

Mass extinction?

[gleeaikin]

It may have only been 6.5 miles in diameter, but it left a crater 120 miles wide.

[gleeaikin]

Not to mention Hudson’s Bay.

[gleeaikin]

I seem to recall there had been a lesser die-off of donosaur species about 10 million years before the big one.

[SunkenCiv]

If so, it would be fruitful to look for iridium at the paleontological boundary, as well as an impact crater.

[SunkenCiv]

Yup, only 6.5 miles diameter, left a huge crater -- this artist's conception exaggerated the size of the bolide. :^)

[gleeaikin]

It is my understanding that Iridium has been found at many boundary sites besides Gubbio in Italy. Certainly if any fossils of Saurids are found above the 65M boundary, then testing for Iridium should be done above and below the fossil.