The claim that lava was dated by K-Ar to approximately 1 million years.
This was done by Steve Austin and "published" in Creation Ex Nihilo
Technical Journal (sometime in 1997). I found it at
http://www.icr.org/research/sa/sa-r01.htm
It may be that he really dated inclusions in the lava, and other work has
shown that they are not reset (I assume not completely melted) and retain
some of their own old Ar. A discussion of new lava dating old can be
found at
http://www.cs.colorado.edu/~lindsay/creation/hawaii/html
It is interesting to note that the info in the second site referred data
published in 1968 !! It seems that those using K-Ar methods already knew
of problems (or inappropriateness) of K-Ar dating very young materials.
Al McCarrick