[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

A piece of the bolide?



The March 29, 1996 (v. 271, p. 1806) issue of _Science_ has a short note 
on the discovery of a 3 mm chip of rock from the K-T layer on the bottom 
of the Pacific off the west coast of Mexico.  It is rich in iridium, and 
contains metallic grains that are up to 87% nickel.  It is only the 
second recognizeable meteorite found in all of the cores of deep sea 
sediments ever taken--and "just happened" to be in the K-T layer.  If 
part of the bolide, it would show that it was an asteroid rather than a 
comet.

Personally, I don't know why this is true, but the claim is made that the 
survival of a part of the bolide (that's the word they use!) indicates 
that it struck at a low angle.  It is reported that earlier studies of 
crater assymmetry suggest that the object came in at about a 30 degree 
angle from the southeast.  The core site would be downrange from the 
impact.

If the impact was at a 30 degree angle, would that affect where we would 
place an antipode--i.e., are the Deccan basalts still in the right place? 

*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*-*
Norman R. King                                       tel:  (812) 464-1794
Department of Geosciences                            fax:  (812) 464-1960
University of Southern Indiana
8600 University Blvd.
Evansville, IN 47712                      e-mail:  nking.ucs@smtp.usi.edu