Lake Varve Sediments and the Great Flood

I'm setting up this thread basically to continue a discussion Creationist and I began elsewhere, but anyone is welcome to chime in of course. I'm curious as to how one might reconcile the geological record of lake varves (and marine ones, sure, but let's worry about lacurstrine sediments first) with A, the idea of a global flood around 4000 years ago and B, an earth formation date of around 6000-10000 years ago.