Winnowing segregates gold nuggets into placer deposits in streams, and winnowing segregated bone material into clutches and piles on the Cretaceous shoreline. Both processes, waves and tides, bring water to the shore and carry it away. The winnowed fossil material forms a thin bed of fossil conglomerate. Several individual dinosaurs or dinosaur species may be present along with non-dinosaurian vertebrate and invertebrate hard parts. Fossils in the conglomerate layer are typically not whole, and are highly comminuted and abraded.
Sharp corners are absent and boney processes are commonly removed and smoothed away.
The conglomeratic layer of fossils in not graded or preferentially oriented. The overlying and underlying layers of sediment are not graded either. Research indicates that lagoonal and coastal lowland beaches on the lagoon do not have concentrate deposits, perhaps because of insufficient wave energy. The concentrate fossils are graded within a few centimeters of the tempestite base. The concentrates are like that found at the shoreline but are mixed with whole, sand-filled marine bivalve shells.