VOLCANO MADNESS: Re: [Geology2] Here We Go Again--Alvarez Theory on Dinosaur Die-Out Upheld: Experts Find Asteroid Guilty of Killing the Dinosaurs

Tuesday, April 2, 2013

Re: [Geology2] Here We Go Again--Alvarez Theory on Dinosaur Die-Out Upheld: Experts Find Asteroid Guilty of Killing the Dinosaurs

Hi Kenneth,

At Coon Creek, the fossils we found did not appear to be etched, but seemed to have been fairly protected by the thin layer of water lapping the beachhead of the Mississippi Embayment. Also, these fossils were embedded in a protective layer of marl. The infant mosasaur found was mostly bone, but then it was probably fodder for aquatic critters crowding the shallows for scavenging. Therefore, I think your conjecture is accurate.

The layer of iridium and detritus denotes something not usually found in bedding--an event that occurred very fast. I've got to get down there again and take pictures and samples before I leave Tennessee (if I ever do). Perhaps I'll find something neat in the interim.

Lin

On Tue, Apr 2, 2013 at 7:01 AM, Kenneth Quinn <mosasaur47@email.msn.com> wrote:

If I may address this issue -

There are multiple reasons for there being no fossils right at the boundary.

1) Dinosaurs were never extremely abundant in the first place.

2) Only an extremely small percentage of the fauna alive at a certain point in time is preserved in the fossil record. They pretty much have to be buried immediately in fluvial or marine sediments - a very rare occurrence.

3) It seems likely that the impact that cause the extinction event also caused an acid rain of global proportions and great intensity. I have not seen any speculation on its effect on carcasses and skeletons - perhaps it contributed to destruction of any bones that were left from the dying off.

4) Only a very small percentage of the K/T boundary is currently exposed. No bones have been found in the boundary layer YET.

These 4 points are what occur to me off the top of my head. There may be others.

In support of point 3 - I have collected reworked Cretaceous fossils (ammonites) just above the boundary that seemed to be considerably etched. This may have been purely mechanical rather than chemical, I admit.

Pardon my ignorance, I keep read that there hasn't been any dinosaur fossils found in the impact layer, fossils have only been found below the iridium layer, but nothing in it and that it is an extremely small layer. If it caused the dinosaur extinction why no fossils?

Bre