During the Bears and Carolina game, A facemask penalty was called on a running play where the ball carrier fumbled the ball thru the end zone. The ruling, after a review, declared the play a touchback and the awarded the Bears a 1st & goal for the facemask penalty. I was under the impression that a facemask penalty was enforced at the seceeding spot. Since the result of the play was a touchback, shouldn't it have been 1st and 10 at the 10 yd line with Carolina in possession?

In NCAA this would be enforced from the end of the related run, which in the case the run ended where he fumbled it. The NFL rule is apparently a spot foul on plays that result in a toucback. There is no way for the ball to go over to the defense since they fouled prior to gaining possession. This is what we call the "clean hands" rule. In this play they got the ball without "clean hands", so there is no way they keep the ball unless the penalty is declined.

Carolina fouled before the fumble. Therefore, Chicago keeps the ball. If the same foul had happened on a Panther interception, the foul would have allowed the Bears to keep the ball. The fumble is no different.

One other thing I noticed about this play... it looked on replay like the ball was fumbled at around the 1-yard line, and went forward into the end zone and out of bounds. Since the facemask penalty would be enforced at the end of the related run (the spot of the fumble), it seems like the penalty should be half the distance from the 1, which would be the half-yard line, and the Bears should have 1st-and-goal from that spot. But the officials enforced the penalty from the previous spot (the Carolina 7), giving the Bears 1st-and-goal at the 3 1/2. I'm curious as to why the penalty was enforced from the previous spot and not the spot of the fumble (end of the run).

The penalty was enforced from the spot of the foul. From another forum here is a copy of how this applies to the NFL.
"The fact the play resulted in a touchback made this a change of possession, so it is enforced as a foul during a run followed by a change of possession. The spot of enforcement is either the end of the run or the spot of the foul whichever helps the offense the least. That's why he penalized from the spot of the foul."

OK that makes sense. Thanks Jason.

Jason,
You are right on it! When I saw the play I said that is a TB (w/o knowing about the face mask foul). Even the play in the Denver Game was questionable but couldn't prove any thing by the replay.