Re: extinction

[xm9@sdcc12.UCSD.EDU (richard g. adair)]

> They were produced by massive volcanic flows without associated
> explosive or ejective eruptions.  This sort of volcanism produces
> extensive *sheets* of lava hardening into basalt.
> 
> Similar flood basalts (layers of laval sheets) are found in Idaho
> (Craters of the Moon Park), Siberia, Antartica, and a few other
> places.

Much of Eastern Washington and some of N. Oregon comprise notable
flood basalts as well, a much greater volume of rock than any of the
others you mentioned, expect for the Deccan Traps. The Columbia River 
cuts through these basalts along most of its American course.  

> 
> Volcanism of that sort is not occuring anywhere on Earth at this
> time (although Iceland may be somewhat similar).

No, not really.  Iceland appears to be a spreading center 'filtered'
through continental crust.  This is probably not the appropriate
model for high-volume flood basalt events.

rick adair