Sprinkle both sides of lamb chops lightly with garlic salt.
Place in 10-inch square casserole with meatiest portions toward outside of casserole.
Spoon one-fourth of the marmalade on each lamb chop; top each with 1 orange slice.
Microwave at MEDIUM-HIGH (70%) until lamb chops are desired doneness, 12 to 13 minutes.
Rearrange lamb chops once during cooking.