Haughton impact crater is located on Devon Island, Nunavut in far northern Canada. It is about 23 km (14 mi) in diameter and formed about 39 million years ago during the late Eocene. The impacting object is estimated to have been approximately 2 km (1.2 mi) in diameter. Devon Island itself is composed of Paleozoic shale and siltstone overlying gneissic bedrock.