Cuban evidence of K/T impact

[bh480@scn.org]

From: Ben Creisler bh480@scn.org

>From a Cuban news source:
http://www.periodico26.cu/english_new/features/meteorite200
605.htm

Meteorite Evidence in Cuba

The catastrophe that wiped out those reptiles and many 
other species 60 million years ago has been clarified. The 
meteorite that caused their deaths left its largest 
evidence in Cuba.
Today it seems to be definitely accepted, said Dr. Manuel 
Iturralde to Sol y Son. Dr. Iturralde, a specialist with 
Cuba?s National Museum of Natural History, explained that 
the massive extinction 65 millions years ago in which 
dinosaurs disappeared was caused by the meteorite of 
Chixculub, Mexico.
The hypothesis of the ?killer meteorite? emerged in 1979 
when physicists Harold Urey and Luis Álvarez found 
abnormal concentrations of iridium in sediments from the 
late Cretaceous period Iridium is rare on Earth, but there 
is plenty of it in asteroids and it is thought that the 
impact of one with a diameter of over six miles induced 
earthquakes, volcanic eruptions and a ?nuclear winter? 
with a sudden drop in temperature.
Such an impact would make a crater with a 150 mile 
diameter. Since none like that was found on land, they 
looked for it at sea. In 1990, Bohor and Seitz, two US 
geophysicists, discovered that 650 thousand centuries ago 
a giant meteorite fell in Chixculub, in the Yucatan 
peninsula, Mexico, near the south-western coast of Cuba.
The evidence should be in the geological strata of the 
late Cretaceous or early Tertiary periods, (K-T layer, 
according to experts), for its lower part contains fossils 
of the disappeared animals, which were not present in the 
upper part. Also there should be quartz particles crushed 
by the impact, as well as microtectites, or crystal balls 
formed when the molten rock solidifies, usually found 
around meteor craters. And, of course, iridium.
Cuban Evidence
Iturralde?s attention was caught by a paper published in 
Nature magazine. ?I went to the Cuban areas where 
allegedly were fragments of the impact?, he 
explained, ?but the rocks there were not originated by a 
meteor. Two years later I published a paper on the subject 
in Earth and Planetary Science and Letters.?
In 1996 Dr. Takafumi Matsui, from the University of Tokyo, 
visited Cuba with a project on the Tertiary geological 
limit and signed a collaboration agreement with the Museum 
of Natural History and the Institute of Geology and 
Paleontology. During the past five years several 
expeditions studied the K-T layer in the provinces of 
Pinar del Røo, Havana, Matanzas and Villa Clara.
Unique cuts were found, for if the deposits in Mexico and 
other countries of the area are 6 to 10 feet deep, in Cuba 
they go down to almost three thousand. ?They are unique?, 
Iturralde said, ?and indicate the most complete vestiges 
of the impact and its consequences.?
What produced such unusual thickness? When the meteorite 
fell in Yucatan, what was then the bottom of the Caribbean 
and the edge of the peninsula is now what is found in 
Pinar del Río, Havana and Matanzas. That is, Cuba has 
rocks that were part of the bottom of the Caribbean Sea 
and the Yucatan shores.
An Extraterrestrial Earthquake
According to Iturralde the impact generated a shock wave 
with an earthquake way beyond any of terrestrial origin, 
so great that it provoked an enormous crumbling of the 
continental edge in Yucatan, the Bahamas platform and the 
then existing islands, which at present are the foundation 
of Cuba. The crumbling made deposits hundreds of feet 
thick, gaps with enormous blocks torn from the near 
emerging areas. ?Gigantic tsunamis crashed on the 
Caribbean coasts rolling over small islands and low areas, 
with billions of tons of dust and sand. When they settled, 
that material when to the bottom of the sea and created 
the huge layers that we have found,? said Iturralde The 
impact pulverized the meteorite, rocks were fused and flew 
to the atmosphere, which received that iridium-rich dust, 
crystals generated by the fusion and cooling of the rock, 
and also laminar quartz. Due to the impact, all that is on 
Cuban rocks
Prehistoric Nuclear Winter
Most probably all sea organisms in the Caribbean did not 
survive?, said Iturralde. ?Not only dinosaurs were 
extinguished.? At the International Congress of Geology 
held in Havana, Dr. Ryuji Tada, a researcher from the 
University of Tokyo, said that science links the impact 
with a world environment crisis ?acid rains, fragments 
falling from the sky and cooling for a long period, 
because the particles in the atmosphere blocked solar 
radiation, a kind of ?prehistoric nuclear winter.? 
This brought massive deaths that in turn generated 
plagues, bacteria, fungi and diseases for wildlife and 
flora, which in turn contributed to the death of more 
species. The destruction of plants and forests left them 
without food, the massive fallout and acid rains generated 
chemical changes in the composition of the water in the 
seas, rivers and lakes. 
Many species survived, but also many were totally 
extinguished, like dinosaurs. At present there is a second 
project with universities from Spain and Mexico, led by 
Reinaldo Rojas, the Museum?s director, which will study 
marine life before and after the impact, something that 
was not done during the previous research.
?People sometimes wonder?, concluded Iturralde, ?why so 
much money is spent on studying the past when there are so 
many problems today, but those studies allow us to better 
know the whys of the present and prepares us for the 
future. What happened in the past on Earth could happen 
again, and all that history is in the rocks, so if we 
study them we?ll know what happened, what could happen and 
how to find ways to be prepared for tomorrow.?