There are a number of web sites with calculators for meteorite impact damage eg
www.lpl.arizona.edu/impacteffects/ They are kind of fun reading how a large asteroid such as yours would melt the earth's crust and do us humans in. Saw an interesting doco on Foxtel recently suggesting a decent sized asteroid impact in Antarctica had a contra-coup effect of causing the Siberian traps volcanic event, the possible cause of the geat dying event ~ 200-250 million years ago.
I dare say, your pet rock would well and truly wipe out most species, humans most definately, so stick your head between your legs............................... ...and kiss your a%$e goodbye
