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Gravity survey
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A gravity survey and a new model of the Steinheim crater
Commonly, a 3.7 km-diameter of the Steinheim impact structure is stated. A gravity survey and a detailed morphological analysis, however, suggest a much larger size. A diameter of 6 - 7 km may be reasonable as shown in a paper by K.Ernstson (1984: A gravity-derived model for the Steinheim impact structure. Geol.Rundschau, 73/2, 483-498). The most significant figures of the study are shown below.
Gravity survey
Bouguer gravity map of the Steinheim basin area (encircled) and its surroundings. Contour interval 0.25 mgal.
Bouguer residual anomaly of the Steinheim impact structure. Contour interval 0.2 mgal.
Model calculations. Densities for the model bodies are in g/cm.
Morphological analysis
Profiles of averaged topography of the Steinheim crater. Top profile: Averaged topography based on 32 radial profiles. Bottom profile: Averaged topography from 16 southern (to the left) and 16 nothern (to the right) stacked profiles. Dotted line: Left-hand profile mirrored at the zero axis and shifted vertically 20 m. The 3.7 km bar matches to the average rim crest diameter according to RODDY (1977).
Stratigraphic uplift/diameter relationship for terrestrial impact structures, sedimentary target. 1 = Steinheim, 2 = Flynn Creek, 3 = Crooked Creek, 4 = Middlesboro, 5 = Serpent Mound, 6 = Red Wing Creek, 7 = Sierra Madera, 8 = Wells Creek, 9 = Gosses Bluff, 10 = Strangways, 11 = Kilmichael (impact origin now questioned). After GRIEVE et al. (1981). Open circle: Steinheim crater according to the postulated larger diameter.
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