Your paper carried an article (V. Vajda, S. MacLoughlin: Fungal Proliferation at the Cretaceous – Tertiary Boundary, Science, Vol. 303, 5. March 2004, 1489), in which the authors presented plant fossils found in the Moody Creek Mine, New Zealand.
According to their findings, the sudden disappearance of the earlier vegetation was followed by a fungal layer that, in turn, gave place to a basically different type of vegetation in a short time. This change happened very quickly. The whole process is contained within a few centimeters wide layer. The iridium concentration of these layers shows a significant rise and fall.
The authors have taken for granted in their evaluation of the findings that an impact of a bolida took place on the K-T boundary, which caused mass extinctions all over the Earth. Based on this hypothesis, they considered the changes in the Ir concentration a proof of the simultaneity of the studied events and the impact.
But these findings do not prove this. Rather, they disprove it!
Presently, there is no known method for determining the date of a 65 million years old event with an accuracy of even a few hundred years. This is also true for the exact date of the K-T boundary. The most we can know about these findings is that they happened somewhere around the supposed K-T boundary, give or take a few hundred years.
This would only be true if there was any proof that these events happened approximately 65 million years ago.
The changes of the Ir concentration do not prove this. (I have developed this argument in a couple of articles written 3 years ago. Suffice it to say that the reason behind the so-called Ir anomaly might be a drawn-out falling of Ir. It does not contradict the selectivity of the extinction of animal life, while the selective effect could not have taken place in the case of an impact.)
The authors have not given the dates of the studied events. They must have failed to do so because their findings did not yield this information. The speed with which these layers were formed is unknown. It could have been only a few months, a few years (or possibly just a few weeks) while the fungi dominated the place.
So we do not know when, nor for how long, these layers were being formed.
2. The events
The complete cycle of the rise and fall of the Ir level took place in an approx. 2.3 cm thick layer, of which 1 cm is below the K-T boundary. Allowing for the dead line correction, this section has more than 20 percent of the total increase. Also, there is a low peak 3 cm below the K-T boundary.
How did the Ir concentration get higher before the time of the supposed impact? The impact theory does not explain this.
By the end of the process, the Ir level fell to between one half to three-fourths of the original value.
Why was the Ir concentration lower after the process, than before? This is also left unexplained by the supposed impact.
Another argument against the impact theory is that the Ir concentration increased and decreased relatively slowly. In case of an impact, the Ir concentration jumps suddenly to a higher level then returns slowly to its original value.
The vegetation seems to be undisturbed by the almost 2.5 times increase of the Ir level, but perished due to the increase above that.
The fungal layer is only 3 cm thick and precedes the Ir peak.
Why did the fungi disappear before the peak, and why did new plants show up as early as that? If the amount of particles containing Ir was characteristic of the amount of bolida residue falling back upon the surface of the Earth, then why did these events happen during the strongest falling and not later, after the falling had stopped?
3. The amount of Ir
Presently, about 2-6 kt. of bolida fragments falls on the Earth each year, resulting in an approx. 0.1 ppb Ir concentration in the crust. This means the Ir falling is 0.2-0.6 g per year. (That is, if no Ir gets to the surface from within the Earth. Allowing for that, the correct figure is up to 0.2-0.6 g.)
The elevated Ir concentration in the above mentioned 2.3 cm thick layer averaged at 1.1 ppb. Converting that to the whole Earth:
(where e means a power of ten, e.g. 3e2 equals 300),
that is, 1.3e-5 km3.
The result is 1.3e-5x2xe10 t
The supposed chondrit bolida was approximately 1,700 Gt.
The following are possible:
3.1 The Ir concentration of the bolida was the same as those of our times.
So the bolida could have increased the Ir level of the Earth by 170 t.
(Obviously only in case the whole of the bolida remained on Earth.)
Where did the rest of the Ir come from?
3.2 All of the Ir originated in the bolida.
In that case, the Ir concentration of the bolida was about one and a half thousand times higher than that of an average bolida today.
Do we have any proof of this?
4. The generalization of the findings
The studied material originated from a mine in New Zealand. The authors based their speculations about the whole Earth upon this one site. (To be correct, Tschudy and colleagues did find a so-called fern peak – a sudden rise and fall of the amount of fern spores immediately succeeding the K-T boundary – in the Western region of North America dating from the same time. So the short lived appearance and disappearance of a transitory group of plants around the K-T boundary has happened in more places than one.)
Can you draw a conclusion about the whole Earth based on the findings of one single site?
If that site conforms perfectly to the average, then maybe yes. But there’s nothing in this case that would support this.
How wrong can you be?
Let’s see an example.
Borrego Desert is situated in California. At a hilly part of the desert, coming across a saddle, the tourist will think that Fata Morgana is playing tricks on his vision, because he sees a dense forest of several hundred palm trees. As he gets closer, he can see for himself the reality of the mirage, because finally he reaches the famous palm forest of the Borrego Palm Canyon.
This is the only native fan palm forest in the United States. It owes its existence to a stream that has not changed its course for millions of years and brings a constant supply of water winter and summer. Because of the water, the earlier vegetation of palm trees survived in this short and thin strip of land, while it disappeared from the other parts of the desert when the climate turned arid. The palms live right next to the stream and each of them drains a bit of the water, so after a while the stream vanishes. It’s the end. There are no more palms, only the desert plants from then on.
Should the stream disappear or change its course for some reason, a few weeks or months would be enough to see the end of the forest.
What would a researcher find a good 65 million years after this supposed event, if he explored the strata of this site? (Supposing that they stayed in good condition.)
He would find that here was a patch of palm forest throughout millions of years that suddenly disappeared. He would draw the conclusion that the climate rapidly changed from warm and moist to extremely arid. He would not be very far from the truth with that, but if he also assumed that the same thing happened all over the Earth, he would be downright wrong.
Dr. Endre Simonyi