Complex sentence: The feature was surveyed by Commonwealth Trans-Antarctic Expedition, 1957, photographed from the air by the U.S. Navy, 1967, and further surveyed by British Antarctic Survey (BAS), 1968-71.
Split into simpler sentences: The feature was surveyed by the Commonwealth Trans-Antarctic Expedition in 1957 and was photographed from the air by the U.S. Navy in 1967. It was further surveyed by the British Antarctic Survey (BAS) from 1968-71.