Gallejaure is a ca. 60 km diameter structure with a distinct circular central gravity and magnetic anomaly.
References:
Enmark, T., and Nisca, D., 1983: The Gallejaure intrusion in northern Sweden – A geophysical study. Geologiska Föreningen i Stockholm Förhandlingar 105: 287-300.
Lilljequist, R., The Gallejaure structure, northern Sweden. In: I. Gilmour and C. Koeberl (eds), Impacts and the Early Earth. Springer Verlag 364-367.