[meteorite-list] Czech Basin Might Have Arisen Through Mighty Cosmic Impact

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 31 Jul 2007 17:18:11 -0700 (PDT)
Message-ID: <200708010018.RAA25775_at_zagami.jpl.nasa.gov>

http://launch.praguemonitor.com/en/137/life_in_the_czech_republic/10176

Tyden: Czech basin might have arisen through mighty cosmic impact
Czech News Agency

Prague, July 30 (CTK) - Some experts are starting to support the theory
that the fall of a giant meteorite some 2 billion years ago may have
created the Czech basin, surrounded by mountain ranges, reminding of a
crater and easily detectable from high altitudes, writes the weekly
Tyden out today.

Up to recently, the Czech basin's formation has been ascribed to plate
tectonics.

"The plate tectonics, including the earth crust movements, became a
geological religion of the past century. This has slightly overshadowed
the fact that the Earth is also a part of space," said Petr Rajlich, a
university teacher and geologist from the South Bohemian museum in Ceske
Budejovice.

A crater of Bohemia's size "is unprecedented in terms of energy
necessary for its creation. Moreover, its emergence has never been
registered by people in their history. If it had been so, the possible
witnesses would have been the last humans living on the Earth," Rajlich
told the magazine.

American scientists reportedly admitted the "cosmic impact" origin of
the Czech basin when they saw its satellite photo taken at the altitude
of 36,000 km in the late 1980s.

The Americans, however, wrongly put the period of the meteorite's
possible fall at 100 million years ago. In addition, they submitted no
geological arguments, says Rajlich.

Perhaps no other inland country is as easily detectable on a plastic map
as the Czech Republic. "The best explanation for a circular structure of
such dimensions can really be the fall of a meteorite," says Vaclav
Cilek, head of the Czech Geological Institute.

The caved-in earth crust below Bohemia also speaks in favour of the
impact theory, Cilek adds.

"Indeed, the geological origin of Bohemia really shows several unclear
aspects we are unable to properly explain using the old plate tectonics
theory and which could support the impact theory," said Radek Mikulas
from the Geological Institute.

"Nevertheless, the round shape of the Czech basin can also be explained
in many other ways," he said.

Experts are split on the issue, but they agree that geological proofs
would be crucial for the recognition of the Czech basin's "cosmic" origin.

"The whole event would have to be a huge blow in the centre of Europe
that would transform [the composition of] the upper part of the Earth's
mantle into considerable depths. As a result, brectias and other unusual
rocks would have to occur in the area now," according to Vladimir
Bouska, a late expert and Charles University teacher.

According to Rajlich, more and more proofs have been uncovered in
support of the cosmic impact theory.

Some Czech minerals show a dense network of defects caused by extreme
pressures and comparable with those registered after underground nuclear
blasts, he says.

Some rocks in Bohemia are mixtures of elements that do not "match" each
other, as if formed of meteorites and the Earth's crust.

Minor diamonds and titan oxides have been found 15 km to the north of
the Czech-German border. They arose under extreme pressures as a
possible product of the crater's shock waves, Rajlich says.

Some types of rocks in Bohemia are identical with the rocks uncovered in
Vredefort, South Africa, and Sudbury, Canada, the world's two craters
with supposed cosmic impact origin, Rajlich says.

In addition, there is no better explanation for the Czech basin's
circular shape with the depression that is the deepest some 50 km
southeast of Prague, he says.

The possible meteorite whose fall might have formed what are the Czech
Lands now, was some 20 km long and it hit the Earth at a speed of 50 km
per second. It caused an explosion identical with thousands of nuclear
bombs.

Millions of cubic metres of rocks were shifted and even a large part of
mass evaporated.

It created a hollow with a 300-km diameter and two kilometres deep. The
crater's edge, on its part, moved 2 km upwards. It is now copied by the
Czech border mountain ranges, Tyden writes.
Received on Tue 31 Jul 2007 08:18:11 PM PDT