Good morning. I am moving from concrete slab floor to wooden construction with basement, below. Concern that floor will bear the weight of a heavy piece of machinery. Machinery weighs 4100 lbs. Pressure is born over 2sq feet. How do I safety distribute the weight, so that I don't crash the equipment through the floor?

First don't you have to find out if the floor and substructure are safe enough to hold a piece like that? What kind of machinery, that heavy, would you want in your house? Couldn't the moving company determine this for you, of course for an extra charge?

Curious, what is it ?

Do you really mean 2 sq'? Or a 2' x 2' machine, 4 sq'?
Typical residential construction load is 40 psf, 300 lbs concentrated load.
A lot depends on the integrity of the joists/beams/posts you have, the joist span, and movement of the machine such as vibration or shock.
You could sister 3 joists and then build a 32" x 32" brace across them, and put a lally column or 2 under it.
You should also have a slab of wood 32" x 32" or more under the machine to distribute some load from above.
Some of the load goes all along the joists and down outside walls, and some goes straight down the column to the concrete. Even the concrete can give if enough weight is concentrated on it, so sometimes a footing has to be put under the typical slab. But you would have plenty of warning of the concrete starting to break up.
But I think you'd be OK with 3 sisters, a wooden slab and a brace, and 2 lally columns. Provided the house is in good shape.