Architecture of a tide‐influenced river delta in the Frontier Formation of central Wyoming, USA

The Frewens sandstone is composed of two elongate tide‐influenced sandstone bodies that are positioned directly above and slightly landward of a more wave‐influenced lobate sandstone. The 20‐km‐long, 3‐km‐wide Frewens sandstone bodies coarsen upwards and fine away from their axes, have gradational bases and margins and have eroded tops abruptly overlain by marine shales. These sandstones are superbly exposed in large cliffs on the banks of the …