The specific composition of the Roraima Supergroup rocks varies across the formation.

At the base, rocks tend to be more silts and mudstones — finer-grained materials deposited in calmer water.

Higher in the sequence, the rocks become coarser and more dominated by sandstone, reflecting a change in depositional conditions toward environments with stronger water currents or more energetic deposition.

The chemical maturity of the sandstone — the degree to which the original mineral mixture has been processed toward quartz dominance — reflects the extremely long period over which the source material was being reworked.

Mature, quartz-rich sandstone indicates sediment that has been transported, deposited, eroded, re-transported, and re-deposited multiple times over a long period, with each cycle washing out the less chemically resistant minerals and concentrating the quartz.