Are Outliers of the Huronian Supergroup Preserved in Structures Associated With the Collapse of the Sudbury Impact Crater

Several outliers of the Paleoproterozoic Huronian Supergroup are preserved in a 20 km wide arcuate belt northwest of the Sudbury Igneous Complex. Forty years ago it was suggested that these outliers represented the remnants of a discontinuous rim syncline developed around a domal structure. Thirteen years later it was proposed that they were preserved in grabens formed as a result of collapse of the central uplift of a multi‐ring impact crater and the simultaneous emplacement of the Sudbury Igneous Complex. This interpretation has been accepted by most investigators without question, to the extent that the position of the outliers has been used to estimate the size of the supposed crater. Our observations indicate that Huronian strata in the outliers were deposited in a series of paleo‐valleys on a terrane with considerable topographic relief. The asymmetric nature of the fill in some of the outliers suggests deposition may have taken place in half‐grabens. The outliers are preserved in synclines develope...