EE ATTEMPTED TO REMOVE LARGE FLAT ROCK FROM MOVING CONVEYOR IN STICK PICKER AREA ON MAIN SURGE BELT. WHEN HE LIFTED THE ROCK THE CONVEYOR DROVE THE ROCK INTO A CHUTE ABOVE THE BELT PINCHING HI S HAND BETWEEN THE TOP OF ROCK & BOTTOM OF CHUTECUTTING HIS MIDDLE FINGER & TOP OF LEFT HAND.