9

Post-Pliocene. Sands and gravels. Plastic and boulder clays, etc.

Unconformity, with evidence of some flexure and disturbance of Tertiary beds.

Volcanic rocks of the north part of Graham island.

Tertiary, Sandstones, with marine fossils and lignites of Skonun probably point. Miocene. Shales, clays, and lignites of Mamin river and Chinoo-

kundl creek.

Complete unconformity, with evidence of great disturbance. Chief period of mountain making.

Upper shales and sandstones. Coarse conglomerates. Lower shales and sandstones. Agglomerates.

Lower sandstones.

Cretaceous.

EO >

Unconformity, but without evidence of great disturbance.

( - Agglomerates and ash rocks of Logan inlet, etc. (These

Triassic, but possibly represent subdivision D., supra.) possibly pass- Flaggy calcareous argillites and thin limestones. ing below Massive limestones. into Car- Massive dioritic and feldspathic volcanic accumula- boniferous. tions, probably including minor limestone beds,

occasionally schistose.

A comparison of this table with the subdivisions used in this report is given on page 11.

The rocks called Triassic by Dawson, include limestones and black, calcareous, flaggy argillites, and he mapped a small portion of the south side of Maude island as being underlain by this formation. These rocks, together with other rocks of Skidegate inlet, erroneously supposed by Dawson to be Cre- taceous, have been shown through fossils collected by the writer to be lower Jurassic and perhaps Triassic in age, and are termed in this report the Maude formation.

The Cretaceous rocks of Skidegate inlet are described on pages 63B to 77B of his report. Dawson accepts Richardson’s subdivision, to which he adds two members, his complete section being: