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

Re: Big Craters



>From another source (Jerry, I don't have the reference in front of me -- will
fish it out for you -- turn about is fair play, and you are playing fair).

               Crater sizes

Name               Age               Dia. (km)
Chicxulub           64.98 Myr      170
Morokweng      145                    70
Vredefort       2023                   300



This source  estimates Morokweng at 100 km smaller than Chicxulub.   Still
other sources place Chicxulub at =>300.   I think its only fair to note that
many estimated crater sizes are awfully tenuous.

(Insert -- here 'tis, reference that is)

http://gdcinfo.agg.emr.ca/toc.html?/crater/africa_craters.html

Dudley indicates a CO2 spike about the time of the Morokweng impact.  He makes
no connection, and I simply mention the commonality of timing.

Jerry D. Harris wrote:

> NAME OF CRATER:  Morokweng
> LOCATION:  southern Africa
> AGE:  at or very near Jurassic-Cretaceous boundary (with which no mass
> extinctions are associated)
> CRITERIA ON WHICH IT IS BASED:  mostly seismic and gravity anomaly (crater
> is subsurface), but also petrologic and geochemical
> SIZE OF CRATER:  340 km (~154 miles) diameter
> REFERENCES:

snipped