The brief description in the map legend indicates a lithology consisting of interbedded to interlaminated
, pale yellow sand with common siderite concretions and nodules.
and occurs within or upon cyclically interlaminated
to interbedded, thin, horizontally laminated, very-fine or fine-grained grey sandstones and dark grey siltstones.
Rhyolite of the Porten Road Formation continues for another 100 m downstream and is followed after a gap of 50 m by greyish green silty mudstone interlaminated
with fine-grained, greyish brown sandstone inferred to again represent the lower part of the Eel River Formation.