The frequency of sedimentary layers between basalt flows increases vertically. Contacts between sediment layers and basalt flows are often either sharp, baked, or erosive. Dune bedforms are preserved beneath one basalt flow. Interlayered conglomerates, pebbly sandstones, siltstones, and mudstones form fining-upward sequences between basalt flows. These fining-upward sequences may reflect gradual abandonment of the braided system or waning flood deposition.
Conglomerates contain clasts of basalt, granite, and sometimes red phyllite.
Some layers of conglomerates and coarse sands have thin horizontal layers of fine sand. These conglomerates record deposition from bars. Paleocurrent data indicate southward transport.