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Re: I NEED INFORMATION

Gianfranco Martinis schrieb:

> Hi to all,
> Can someone on the list help? I need some information about the RIO
> CUARTO impact event. Thanks a lot in advance.



>  Teardrops on the Pampas, P.H.Schultz and J.K.Beatty, Sky + Telescope,
> April 1992, pp. 387-392 (excerpts): At least 10 craters with ragged
> interiors and raised rims are preserved on the broad plain of the
> Pampas. A frothy stone collected from a roadside, proved to be a large
> impactite. Its interior is laced with deformed grains of quartz, clear
> evidence of the enormous pressure at work during a high-enery impact.
> It appears that the Rio Cuarto Complex was produced by an asteroid
> approaching from the northeast at no more than 15° from horizontal. In
> laboratory experiments, the width of a crater produced in sand by a
> 90° impact is about 50 times the diameter of a 5-km-per-second
> projectile. But this ratio drops for low angles, as does the energy
> delivered to actually make a crater. Thus, the chondrite responsible
> for the Northern Basin (4.5 x 1.1 km), the largest member of the Rio
> Cuarto complex, was something like 150 m across, about three times the
> diameter of the asteroidal fragment responsible for creating Meteor
> Crater, Arizona. Assuming an impact velocity of 23 km/s, typical for
> Earth-crossing asteroids, the energy released at the Rio Cuarto site
> was roughly the equivalent of a 250-megaton bomb - 10 times the punch
> delivered at Meteor Crater and 30 times more powerful than the 1908
> Tunguska event in Siberia. Although the craters' precise age needs to
> be determined, they are likely well under 10,000 years old (see also
> P.H. Schultz and R. Lianza, 1992, Nature 355, pp. 234-237).

Well, Gianfranco, this is what I have got at the moment. I do hope it
helps. I'm trying to collect more background information. I'll let you
know as soon as I've got more on this impact scar.

Kindest regards,

Bernd (Pauli)
Teacher
Gymnasium Sandhausen
References: