If you're really worried about cracking the basement floor, you have a couple of options for distributing the load.
1. Get a scrap piece of 1/2" plate steel, 12 to 18 inches square. You'd be looking at between 20 and 30 pounds per each piece. Put down a piece of vinyl sheet on the floor, put the plate steel on top of the vinyl, and there's your pad.
2. This might be even better if you have areas where you get standing water in the basement, and the stuff is easier to get. Get a pressure treated 4x4 and some end-cut treatment. Cut it in 1 or 2 foot lengths, and bolt them together. Put end cut treatment on the whole mess (not just the cut ends). Put the vinyl on the floor, the wood block on top, and there's your pad. You can even attach the column base to the wood with a couple of lags.