Meteorite Craters: Identifying Characteristics

[Mechanical Bliss]

The intention of this thread is to serve as an addendum to previous threads on catastrophic meteorite impacts and their incompatibility with YECism. It's had to be repeated so often, so I thought this could be referenced instead of having to repeat ourselves every time someone claims meteorite craters aren't actually meteorite craters (probably should have done this a while ago, but better late than never). Previous threads:

A Comprehensive Look At The Problem of Meteorite Craters on a Young Earth (Mistermystery)
Crater impacts. (image heavy) (Mistermystery)
Massive Volcanic events and earth impact catastrophes falsify young earth (Frumious Bandersnatch)
Meteorite impacts: how do those fit in with YEC? (Pete Harcoff)

The critical question those threads pose is how these impacts could exist on earth if the planet were only a few thousand years.

This thread tries to show why we know the most catastrophic of these craters are indeed what geologists conclude them to be.

1. Geochemical Anomalies

The most famous geochemical anomaly associated with a meteorite impact is the Iridium-rich clay layer associated with the Chicxulub Crater (Cretaceous/Tertiary meteorite impact, 65 Ma). This layer has been identified globally and consistently at the same age in the stratigraphic column.

This anomaly cannot be produced from erosion of the crust because of the low abundance of Iridium in crustal rocks. The only other plausible explanation is from flood basalts, but they are also relatively low in Iridium content relative to meteorites whose geochemistry we have measured. Flood basalts do not explain the fact that this anomalous concentration of Iridium is found globally either. A meteorite impact where dust would enter the atmosphere does explain this.

We also find anomalous amounts of carbonaceous soot that can result from widespread fires as hot ash, ejected from the impact site, caused vegetation to catch fire.

Here is a diagram that plots the Iridium concentration of rocks in Italy versus the age of the rocks. Note that at the K-T boundary (~65 Ma), there is a sharp spike in the iridium concentration of the rocks. And remember, this is in Italy and the impact site is in Mexico.

2. High Pressure Mineral Polymorphs

One polymorph of the common rock forming mineral, Quartz, is Stishovite. It is a high pressure form of quartz that has only been found at nuclear explosion sites and known impact craters. It has been found in the Cretaceous-Tertiary boundary clays and at the impact site.

Here is a pressure-temperature phase diagram for SiO2 that shows the known pressures and temperatures at which the configuration of SiO2 that forms stishovite occurs, and as you can see, it only forms at high pressures:

http://www.geol.ucsb.edu/faculty/hacker/geo102C/lectures/silica.jpg

3. Shocked Minerals

When high pressure shockwaves pass through minerals, such as quartz, linear dislocations form in the crystal structure that are very characteristic. Shocked quartz is also found near nuclear explosion sites and known meteorite craters.

Here are two pictures that show the difference between the two. Geologists can take thin sections of rocks and put them under a petrographic microscope to use polarized light to identify minerals.

The first picture is of a relatively normal quartz crystal in polarized light. The second picture is of a shocked quartz crystal in polarized light. There are clear shock laminations in the second photo.

(Normal Quartz)

(Shocked Quartz)

4. Tektites

Microtektites are essentially glass spherules with a felsic composition (the same as continental crust). They range from tenths of millimeters to a few centimeters. Glasses form as a result of rapid cooling of rock. Rapid cooling does not allow minerals to form large crystals. Tektites form as a result of rapid cooling of melted continental ejecta as it enters the atmosphere.

5. Crater Breccias

Breccia is a type of sedimentary rock comprised of larger pebble-sized clasts of rock with angular edges cemented into a matrix of fine grained sediment. Their source is shattered rock that is not transported by ice, liquid water, or wind because the clasts are not rounded; instead they are jagged.

Drilling of craters indicates both melting and brecciated rock that would indicate an impact. Here are drilled cores from the Chicxulub Crater that shows what breccia looks like:

---------

So now we know that there are characteristic features that are used to identify meteorite craters as actually resulting from the impact of a meteorite. Some of these characteristics can only form naturally in this way due to the energy released by a large scale impact. All of them are consistent with what we should predict from a meteorite impact. No other explanation fits all of these characteristics of large scale impacts.

That just leaves questions such as why these impacts occurred all over the planet (and other bodies in our solar system) and in a short period of time without affecting life on earth (or even humans noticing them), not to mention why this has not occurred any time recently. They are inconsistent with YECism.

Sources:
Condie, Kent. C and Sloan, Robert E. Origin and Evolution of Earth: Principles of Historical Geology. New Jersey: Prentice Hall, Inc., 1998. (Image 1 - Iridium Anomaly)
http://www.classzone.com/books/earth_science/terc/navigation/home.cfm (Image 3 - Shocked Quartz)
http://secure.thetech.org/exhibits_events/nhhm/essay.html (Image 4 - Tektites from K/T Boundary Region)
http://www.icdp-online.de/sites/chicxulub/news/news.html (Image 5 - Breccia from Chicxulub Scientific Drilling Program)

 

[HRE]

You must spread some Reputation around before giving it to Mechanical Bliss again.

That about sums it up...

 

[And-U-Say]

The intention of this thread is to serve as an addendum to previous threads on catastrophic meteorite impacts and their incompatibility with YECism. It's had to be repeated so often, so I thought this could be referenced instead of having to repeat ourselves every time someone claims meteorite craters aren't actually meteorite craters (probably should have done this a while ago, but better late than never). <snip>
So now we know that there are characteristic features that are used to identify meteorite craters as actually resulting from the impact of a meteorite. Some of these characteristics can only form naturally in this way due to the energy released by a large scale impact. All of them are consistent with what we should predict from a meteorite impact. No other explanation fits all of these characteristics of large scale impacts.

That just leaves questions such as why these impacts occurred all over the planet (and other bodies in our solar system) and in a short period of time without affecting life on earth (or even humans noticing them), not to mention why this has not occurred any time recently. They are inconsistent with YECism.

Don't hold your breath. YECs cannot begin to comprehend this material, it is too powerful an evidence for them to squeeze into their little paradigm, so they go into cognative denile. A river in North Africa. My prediction: no responses.

 

[Bargainfluger]

My prediction: no responses.

Five day forecast: Same as the other one.

 

[Vastavus]

I nominate this for a silent thread, it is just too good.

 

[Mechanical Bliss]

Don't hold your breath. YECs cannot begin to comprehend this material, it is too powerful an evidence for them to squeeze into their little paradigm, so they go into cognative denile. A river in North Africa. My prediction: no responses.

You're right, I wouldn't want to suffocate.

But we so often have YECists stomping their feet in other threads yelling "you guys never falsified YEC or presented any evidence" when there are scads of threads here doing just that, which lie dormant for months without any response from YECs.

I tired to simplify it and explain succinctly (though I suppose it was a lengthy OP) so they could understand the material if they decided to read it. It should be possible for anyone to understand, but it's a question of whether Morton's demon is at work or not. I even added some pretty pictures. But your prediction will likely stand, as it has been the case for most threads that deal with YECism. It just serves as something else we can point to when needed.

 

[The thinker]

This is why I believe in evolution

 

[HRE]

Woudn't it be funny if we went through the Archive thread and bumped every single thread that had virtually no response? Flood the first two pages?

 

[The thinker]

If you gave the thread a more interesing name... like "proof that YECism is not true" then you will probably capture more peoples attention and maybe replies..

 

[Split Rock]

You're right, I wouldn't want to suffocate.

But we so often have YECists stomping their feet in other threads yelling "you guys never falsified YEC or presented any evidence" when there are scads of threads here doing just that, which lie dormant for months without any response from YECs.

I tired to simplify it and explain succinctly (though I suppose it was a lengthy OP) so they could understand the material if they decided to read it. It should be possible for anyone to understand, but it's a question of whether Morton's demon is at work or not. I even added some pretty pictures. But your prediction will likely stand, as it has been the case for most threads that deal with YECism. It just serves as something else we can point to when needed.

U kant proove that the Upheaval of the Flood could not create the rocks that u showed in the OP. The catostofic effects of the bursting forth of the Fountains of the Deep could easily generated the pressures required to make these rocks. Plus, what you call impact craters could easily be Sink Holes associated with the receding of the Flood waters. You kant PROOVE it didn;t!!111!!

Thank u. P.S. The pictures are very pretty.

 

[And-U-Say]

You're right, I wouldn't want to suffocate.

But we so often have YECists stomping their feet in other threads yelling "you guys never falsified YEC or presented any evidence" when there are scads of threads here doing just that, which lie dormant for months without any response from YECs.

I tired to simplify it and explain succinctly (though I suppose it was a lengthy OP) so they could understand the material if they decided to read it. It should be possible for anyone to understand, but it's a question of whether Morton's demon is at work or not. I even added some pretty pictures. But your prediction will likely stand, as it has been the case for most threads that deal with YECism. It just serves as something else we can point to when needed.

If it seems that I insinuated that you should not have posted this, please accept my appologies. Your post is an excellent summation of the topic, and I am glad you put it together. I will keep it as a reference, of course. I was just making a prediction of the responses. I hope you took it as that and nothing more.

 

[Mechanical Bliss]

If it seems that I insinuated that you should not have posted this, please accept my appologies. Your post is an excellent summation of the topic, and I am glad you put it together. I will keep it as a reference, of course. I was just making a prediction of the responses. I hope you took it as that and nothing more.

I did take it as such--just being half-lighthearted and half-serious in reply. I'm glad it serves a purpose for you and hopefully others here. Your prediction as far as responses go will likely stand, as it has been the case for other similar threads on many topics by many people.

 

[And-U-Say]

I did take it as such--just being half-lighthearted and half-serious in reply. I'm glad it serves a purpose for you and hopefully others here. Your prediction as far as responses go will likely stand, as it has been the case for other similar threads on many topics by many people.

Good! Then we can wait in patient futility for a reasoned reply.

 

[And-U-Say]

I am far too interested in what replies might occur (granted their low probablility) to let this thread sit.


Responses?