Shatter cones from Haughton Dome, Devon Island, Canada

Abstract

SHATTER cones, products of shock metamorphism, have been discovered at Haughton Dome and indicate a meteorite impact origin for this circular structure. Haughton Dome is centred at 89°40′W, 75°22′N on Devon Island in the Canadian Arctic Archipelago. Although structurally a dome, it forms a topographic depression incised on the regional plateau (Fig. 1). The inner, circular basin, 17–18 km diameter, has an average elevation of 140 m above sea level compared with regional elevations of 340–400 m. It is surrounded by an annular ridge with elevations averaging 270 m above sea level. In the southern portion of the structure the ridge is not pronounced, but forms a shoulder on the gradual upward slope to the regional plateau, approximately 17 km from the centre. Streams draining the basin have dissected the ridge in the northern portion into an arc of isolated hills. Steep-walled drainage valleys outside the ridge are circumferential or tangential to the structure and enhance its circular appearance.