Fossiliferous gravelly quartzose sand and calcarenite a few metres thick, penetrated by Australian Mining Corporation drilling 6 km west of Seven Mile Swamps, has a foraminiferal age of middle to late Longfordian. The frequent Sherbornina cuneimarginata Wade (range top is top Longfordian), has not been recorded previously from the Eucla Basin. The unit may correlate as an early phase of Nullarbor Limestone (or Colville Sandstone), as a late phase of Abrakurrie Limestone or equivalent, or as a new intermediate unit between these. There is a need for more accurate resolution of ages and spatial relationships of these formations by further regional mapping, sampling, and foraminiferal analysis.