Darn, explorer just crashed in the middle of my reply. I'll try again.
Interesting article Mal. I think I understand now the confusion I had regarding "mud".
I confess, it is late and i haven't read the whole article, but did read the part about mud. Ron says that mud is not defined scientifically. I come from a background where it is defined. Mud is any combination of silt- and mud-sized particles in geology. It turns out that you cannot physically pound any common Earth minerals into silt- and clay-sized particles. The only way to get them so small is through chemical weathering. A great example is the red soil you see in certain warm latitudes. This is a clay derived from the chemical weathering of feldspar. Since quartz does not weather chemically, you cannot have quartz silt or clay. And so to me, you can't have quartz sand or gravel in mud. But now that I understand what Ron and probably the ecosystem people mean by "mud" (a range of particle sizes including sand and small pepples), I agree that it can be just as good as any DSB for nitrate removal. I don't see how it can be *better* though.
Really cool, thanks again!
sam
