Oil pressure ok gauge while driving reads 40 to 60 psi. Dip stick reads nothing, no active leaks found no evidence in exhaust. That I'm burning. No warning light etc. What's going on? Emergency

 

When was the last time you physically checked the oil level? (Time an miles?)
Has it been checked on a level surface? At least 5 minutes after shutting down the warm engine?
Check that the oil pan plug is in place and not leaking! (I know then you should have the oil pressure warning light AND the gauge reading low. - Just to make sure.)

Then check the radiator (when cold) by removing the cap from the radiator and check for oil in the water.
Does your Blazer have the remote oil filter with the heat exchanger on the radiator?
Check on the lower side of the left front wheel well inside the engine bay. If the hoses are leaking from the remote oil filter it can leak into the frame and onto the protective plate. You can loose a quart and have not a single drop on the floor.

If nothing found, I'd start by putting in oil, to normal fill level, note the mileage and date, drive for a 10 miles and re-check on the same level spot when cold, or under the same conditions. (This because now it's important to see even small differencies.) Make sure you measure accurately in possibly the same conditions i.e. always on the same "flat" spot 10 minutes after shutting it down. If no change is observed after a short drive, take measurements in longer intervals, say 50 miles or a convenient distance i.e. going and coming back from work.

Oh, and not to forget. Check somehow that you have the correct dipstick length. If it has been your car for a long time and always has been reading correctly it should be o.k. If it is a new truck or dipstick, re-check. Had that once on a friends car. Wrong stick (too short), overfilled with oil when filling to that dipsticks marks and consequently dumped the oil during a short time. When the engine was happy again, the dipstick read below MIN.