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<p>Gravity data are “nonunique” in that a gravity anomaly can be explained by many bodies with different properties. Similarly, in seismic data, the strength of a reflection is dependent on the product of the density and the seismic velocity, so the nature of a reflection cannot be used to determine the density below an interface when the velocity is unknown. In a previous gravity study, we had concentrated on shallow features (model α), which implicitly assumed that a number of the deeper reflections were due to an anomalous layer, thick enough to cause reflections from its upper and lower surfaces that do not cancel and that the density above and below this thick layer was the same. An alternate possibility is that the material below some of the reflections is a lower-density material called the Deloro assemblage. To test this hypothesized model (model β), we reinterpreted the seismic sections and repeated the gravity study. To allow for the deeper low-density material and account for some shallower reflectors having the Deloro below, we had to make the Porcupine assemblage thinner in places, as it is also of lower density. We found that the gravity data could be explained with the Deloro assemblage below the reflectors. The top of this hypothesized Deloro assemblage varies from 7.5&nbsp;km in the east to 3&nbsp;km in the west of the study area. Models α and β are consistent with the gravity and seismic data, but model β is also consistent with the Deloro being mapped outcropping to the west of the study area and a strong reflector (a banded iron formation) often being observed at the top of the Deloro. Our case study illustrates that modeling and interpretation should often be revised when new information becomes known.</p>