4]

F4l. Geol. Surv. Cat. No. 3487
Locality: northeast side of peak 23 miles southeast of mouth of Attichika Creek.
Conifers
Sequoia langsdorfii (Brongniart) Heer
Angiosperms
Platanus reynoldsii Newberry var. integrifola Lesquereux
Trochodendroides arctica Heer
Populus carneosa (Newberry)
Corylites hybridica? Seward and Holltum
Celastrinites insignis (Heer)
ef. Oreodaphne coushatta Berry
Myrsinophyllum groenlandicum (Heer)
Rhamnites sp.
Pterospermites sp.
Age: Paleocene

F42. Geol. Surv. Cat. No. 3488
Locality: 3 miles east-northeast of mouth of Niven River.

Ferns
Sphenopteris (Asplenium?) cf. S. miertschingi Heer
Aneimia sp. (fertile)
Conifers
Sequoia langsdorfii (Brongniart) Heer
Sequoia sp. (with foliage like many American specimens
referred to Glyptostrobus europaeus, and cones smaller
and more oval than those of Sequoia couttsiae (Heer)
Elatocladus (Taxodites?) tinajora (Heer)
Angiosperms

Viburnum contortum Lesquereux
Age: probably Paleocene, not later than lower Eocene

Age
The paleontological evidence indicates that the formations of the
lower division belong, in places, to the lower part of the Upper Cretaceous
epoch, and those of the upper division to the Paleocene. As no stratigraphic
break has been recognized within the Sustut assemblage, the entire Upper
Cretaceous series may be represented.

KASTBERG INTRUSIONS
Distribution

The Kastberg porphyritic intrusions are confined, with possible minor
exceptions, to that part of the map-area lying south and southwest of
Mount Carruthers. They are particularly well displayed in the vicinity
of upper Kastberg Creek between Scallop Mountain and Comb Peak, and
on the east slope of Bear Lake Valley.

Inthology

The rocks of the Kastberg intrusions are grey, buff, or rarely pale
pink, generally distinctly porphyritic rocks, commonly thoroughly weathered
to a depth of half an inch or more. This deep weathering has resulted in
a characteristic soft chalky appearance as well displayed by the numerous
erratic boulders and slabs seen along the trail a few miles southwest of
Yuen Lake. Although these intrusions vary widely in grain size the most