Zest limes for about 1/3 cup zest. Juice limes for a total of 1/2 cup. Zest enough of an orange to measure 2 tablespoons zest, then juice oranges for a total of 1/2 cup.
In a 13 x 9 x 2-inch glass dish, mix together lime zest and juice, orange zest and juice, garlic, canola oil, brown sugar and 1/2 teaspoon of the salt. Add pork chops and turn to coat. Cover; refrigerate for 6 hours or overnight.
Heat gas grill to medium-high or prepare charcoal grill with medium-hot coals. Remove pork from marinade and sprinkle with remaining 1/2 teaspoon salt and the black pepper.
Grill pork chops for about 12 minutes, turning halfway through, or until internal temperature registers 155°F on an instant-read thermometer. Serve with a thin slice of Lime Butter and grilled corn.
Add butter, chives, parsley, dill, lime zest, lime juice, salt and pepper to a blender or food processor. Whirl until smooth. Scrape the blended butter mixture onto a sheet of plastic wrap and shape into a log. Refrigerate until ready to use.