Three small problems
Posted by epgrondine at 01:26, 05 Mar 2010I see where all the experts got together and decided that an asteroid impact at Chicxulub killed the dinosaurs.
The first problem is that it was a COMET that hit, not an asteroid, and we have a sample of it, which you can see by image googling
"kt-fossil".
Second, it was the impact of multiple comet fragments:
http://www.depts.ttu.edu/vpr/dinosaurs.php
http://www.depts.ttu.edu/gesc/Fac_pages/...
The Chicxulub impact intensified the anti-podal Deccan Trap eruption, and then the Shiva impact set it off full bore, not to mention the small Ukrainian impact somewhere in there.
(Gosh, gee, thanks, Benny:
http://arstechnica.com/science/news/2010...
can we discuss the holes in the ozone layer now?)
(By the way, it may be that oil gathers in the cracks caused by impact: Chicxulub responsible for Mexican, Venezeulan and Texas oil?
and Shiva responsible for Saudi, Iraq, and Iranian oil? and Ukraine responsible for Baku oil? Only the oil companies know for sure.)
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Comments
21 February 2009
1 day 3 hours
Hi Epgrondine,
Interesting stuff.
Couple of questions.
I know that there is still quite a bit of debate as to the exact makeup of comets, but i'd be interested to know what you mean by 'COMET' as opposed to asteroid. Do you have a link to the picture? Personally i'd be open to either, but i'd be interested in the evidence for one over another - as academic as it would be for us in the real world.
As for the oil gathering in the fractures around a crater, this sounds right up my ally.
The oil companies certainly would hold the best data, as you would expect since they are invested in knowing about it. They need not be the only ones to know for sure though as it wouldn't be too difficult to assess it for yourself.
It will take a bit of time though. You'll need to superimpose the position of the oil fields over the crater structure, then take into account the 3D geology and the timescales. All possible at home with a printer and enough time. Just not the sort of project the average person spends a few days on for fun.
Just for precision oil gathering in the cracks (fractures) wouldn't be economically important. They just wouldn't have enough volume.
Petroleum geology at its basics goes source>transport>reservoir capture. Faulting and fracturing can definitely assist in permeation from source to reservoir, though in general i think we are talking permeation through rocks with natural porosity and permeability instead of through fractures and faults, though large faults can affect the situation.
I think the reason fractures tend to have a reduced affect is that minerals tend to precipitate along them, so you tend to see the white veining (quartz or calcite for example) that you often see when you look at a rock close up. I guess the relative importance will depend on how numerous the fractures and faults are, as well as their location. Following a large impact there will certainly be alot of fracturing around the crater rim. An assessment of the position of the oil fields relative to this fracturing should suggest an answer.
23 October 2006
7 weeks 5 days
Hi Epgrondine,
Interesting stuff.
Couple of questions.
I know that there is still quite a bit of debate as to the exact makeup of comets, but i'd be interested to know what you mean by 'COMET' as opposed to asteroid.
(I got called away, and will now expand)
Asteroids for the most part come from the asteroid belt which lies between Mars and Jupiter. They are usually fragments of a currently unknown number of planets which were forming there, and likely dirupted by impacts (similar to the one that formed our Moon) during the Late Period Bombardment Event(s) about 4.2-3.9 billion years ago. When they are diverted Earthwards to become Near Earth Objects, they travel on the plane of the planets.
Chondritic asteroids which did not form into larger bodies which were then disrupted are a special class.
Comets start out in the Oort Cloud, and can come in from any direction. Long Period Comets orbit between the Oort Cloud and our Sun over very many years. Short period comets are captured by Jupiter on the way in, and then orbit roughly between Jupiter and the Sun in a few years.
Comets condensed out of the material on the outer edge of the disk which formed our solar system. The condensation appears to have been (is) chaotic. From what has been seen from fragmentation, they often are composed on cometissimals around 30 meters in diameter, which produce 5 kiloton blasts on impact. Two cometissimals stuck together are around 50-70 meters diameter, and produce 15 megaton or so impact blasts.
Then you have the really big comets. These are sent into the inner solar system by gravity when our solar system passes though the plane of our galaxy, the Milky Way. You can see their impacts in the strata of Mars, and in the extinction record on Earth.
It used to be thought that comets were all carbon, carbon compounds, water, etc. What Napier has demonstrated in his new paper is that the metals in that dust condense to the cores of the big comets, and that after they have out-gassed and fragmented these metallic and dark cores can remain.
When headed inbound they can come from any direction, and that is why WISE is so important. It has demonstrated that NASA's current detection strategy is completely inadequate to the task.
Do you have a link to the picture?
Damn, they changed the image name, so the "kt_fossil" image googele did not work. Here, way down the page:
http://adamant.typepad.com/seitz/2007/09...
Personally i'd be open to either, but i'd be interested in the evidence for one over another - as academic as it would be for us in the real world.
There's a big difference among the estimates for comet and asteroid impacts. Try an ELE every 26 million years by comets, instead of every 100 million years by asteroid.
But then that ignores the small comet fragment impacts, which rise from NASA's current 1 per 1,000 years to 1 per 100 years. The medium impacts go from 1 per 10,000 years to 1 per 1,000.
As for the oil gathering in the fractures around a crater, this sounds right up my ally.
The oil companies certainly would hold the best data, as you would expect since they are invested in knowing about it.
Yep - Oh yeah.
They need not be the only ones to know for sure though as it wouldn't be too difficult to assess it for yourself.
It will take a bit of time though. You'll need to superimpose the position of the oil fields over the crater structure, then take into account the 3D geology and the timescales. All possible at home with a printer and enough time. Just not the sort of project the average person spends a few days on for fun.
Just for precision oil gathering in the cracks (fractures) wouldn't be economically important. They just wouldn't have enough volume.
I'm no geologist, so "cracks" may not be the right term - think of emulsification or the fracturing of oil bearing sandstones.
Yes, it's not a few day project. But you can take a few minutes, and map known oil deposits against known craters - of course the problem is you have to place them all at the right geological time, and things have moved a lot over the millions of years.
But you get the idea. Note that the Chicxulub Crater was discovered by oil geologists.
E.P. Grondine
Man and Impact in the Americas
8 September 2009
49 weeks 6 days
**Golly epgrondine**...you sure do know a lot about comets and asteroids! The whole thing about this is that it's a THEORY...even though scientists may agree as to what (may have) happened, it's still only a theory, but one they all agree on.
bleepingdeadalien
23 October 2006
7 weeks 5 days
**Golly epgrondine**...you sure do know a lot about comets and asteroids!
Thanks.
The whole thing about this is that it's a THEORY...even though scientists may agree as to what (may have) happened, it's still only a theory, but one they all agree on.
All the scientists agree but Chatterjee, in the link I gave you. What he has on his side is data.
Amazingly, I pioneered the others' work, and know why the NSF funded Gerte Keller's work, and many years ago when she first published I wrote a response (which is in the Cambridge Conference archives) in which I described exactly what these 41 scientists did in their paper.
(Can't find my original Cambridge Conference note yet,
but see
http://fpmail.friends-partners.org/piper...)
What changed my mind was Chatterjee's data.
not agreement, but data.
I have been wrong before, and retain the right to be wrong both now and in the future.
(Personally, I want to note that while my stroke was pretty severe, the parts of my brain that were doing my book survived. Now if I could just remember where I set my car keys... By the way, I type these replies using one finger on my left hand, and it takes me a long time to write them.)
E.P. Grondine
Man and Impact in the Americas