Haughton impact crater

In 1955, the Geological Survey of Canada recorded the structure — then believed to be a 'piercement' — as part of Operation Franklin. Field geologist H. R. Greiner named it Haughton Dome after Samuel Haughton because of the latter's work in geology of the Arctic. == Description ==

At 75° north latitude, it is one of the highest-latitude impact craters known. The temperature is below the freezing point of water for much of the year, and the limited vegetation is slow-growing, leading to very little weathering. For this reason Haughton retains many geological features that lower-latitude craters lose to erosion. Because Haughton's geology and climatology are as close to Mars-like as can be had on Earth, Haughton and its environs have been dubbed by scientists working there as "Mars on Earth". For example, the centre of the crater contains impact breccia (ejected rock which has fallen back into the impact zone and partially re-welded) that is permeated with permafrost, thus creating a close analogue to what may be expected at crater sites on a cold, wet Mars. The Mars Institute and the SETI Institute operate the Haughton–Mars Project at this site, designed to test many of the challenges of life and work on Mars. The non-profit Mars Society also operates the Flashline Mars Arctic Research Station (FMARS) at this site and conducts similar research. == Sedimentary basin and fossils ==

The western-central part of the structure is partially filled by a post-impact sedimentary basin with a geological unit called the Haughton Formation composed of mudstone and siltstone, which reaches a maximum thickness of , that contains fossils of animals and plants that lived in the region during the Early Miocene, around 24–21 million years ago. At this time, the region had a cool, temperate climate, with the Haughton formation being deposited in a large lake formed by the crater. The crater was surrounded by a forest that included pine, hazel, birch, and alder, with lesser amounts of larch, cypress, and elm. a shrew belonging to the extinct subfamily Heterosoricinae (resembled Domnina), a leporid rabbit resembling Desmatolagus, an artiodactyl of uncertain affinities, the primitive rhinoceros Epiaceratherium, an indeterminate swan, a trout (Eosalmo), and a smelt (cf. Osmerus). == References ==