[SunkenCiv]

from the Wayback Machine, via a 2005 backup of the old hard drive:

Could impact cause a volcano on Earth?
answered by Chuck Wood
Space Studies
Univ. of North Dakota

We believe that broken comets or asteroids - such as machined gunned into Jupiter in 1994 - have hit the Moon (forming an impact crater chain), and a recent scientific report suggests that a line of old impact craters across the central USA was caused by a similar line of impact collisions. In these cases volcanism was not triggered. A big enough impact might trigger volcanic activity, and one scientist suggested that that might be the origin of Iceland, which is very big compared to other ocean hot-spots.

[Gondring]

Just had a similar discussion over lunch yesterday (Shoemaker-Levy style impact chain, and impact-triggered volcanism). That didn’t happen to be you at the table, did it? The discussion that followed had to do with basins and mare.