Foelsche is a partly buried impact structure, the eroded remnant of a former impact crater. It is situated in the Northern Territory, Australia, and named after the nearby Foelsche River. Although little of it is exposed at the surface, and no crater shaped topography is evident, the circular nature of the feature is obvious on aeromagnetic images, a factor that led to its discovery.
The impact occurred into flat-lying Mesoproterozoic sedimentary rocks of the McArthur Basin and most of
the crater is covered by a semi-circular
hill of flat-lying Neoproterozoic sedimentary
rock. The only exposure of
the crater itself are scattered outcrops of deformed
sandstone and breccia around the northern edge of the overlying
hill, which are inferred to be remnants of
the crater rim. The rim is about 6 km in diameter. Evidence indicating an impact origin for the feature includes an abundance of shocked quartz grains in the sedimentary rocks overlying
the crater, The age of Foelsche is not
well constrained, but it must be younger than the Mesoproterozoic target rocks and older than the Neoproterozoic rocks that partly fill
the crater; it has been argued that the age is most likely Neoproterozoic because it appears that
the crater was covered by sediments soon after the impact event.