General Geology

been called Hazelton group and Skeena formation or series. In the vicinity
of Hudson Bay Mountain near Smithers it has been subdivided into five units
largely on the basis of two sedimentary divisions.

These units are:

Lower Cretaceous or Later Volcanic rocks
Upper Jurassic and Lower Sedimentary rocks containing
Cretaceous (a) Upper Jurassic fauna

(b) Blairmore flora

Middle or Upper Jurassic Volcanic rocks

Middle Jurassic Sedimentary rocks (marine);
Middle Jurassic fauna

Lower Jurassic Volcanic rocks

Some confusion exists in these areas with respect to the dating of the
higher sedimentary beds, and with regard to the upper sedimentary division
Armstrong (1944a) stated: “The Upper Jurassic and Lower Cretaceous
sedimentary division is composed of at least 5,000 feet of interbedded con-
tinental and marine strata containing fossil shells and plants. The shell
collections are all of Upper Jurassic or possibly very early Lower Cretaceous
age. The plants represent two distinct flora correlated provisionally with
the Kootenai and Lower Blairmore of Alberta and presumably of Lower
Cretaceous age. In Glacier Gulch, however, fossil shells of Upper Jurassic
or very early Cretaceous age were collected from a bed 300 feet strati-
graphically above a bed containing fossil plants of Blairmore age.” This
discrepancy may be due to faulting not detected at the time the fossils were
collected (E. D. Kindle, personal communication). Armstrong further con-
cluded that no satisfactory stratigraphic division can be made between the
Hazelton group and the Skeena series, and that continental strata comparable
with the Skeena rocks appear at various horizons within the Hazelton group.

The Hazelton group then -at that time consisted of a more or less
conformable series of volcanic and sedimentary rocks (both marine and con-
tinental), extending from a horizon in the Lower Jurassic to early Lower
Cretaceous time—probably Kootenai or Blairmore.

Work in Whitesail Lake map-area did not add substantially to the
knowledge of the limits of this complex group. No definite Upper Jurassic
or Lower Cretaceous marine beds, like those associated with the Hazelton
group elsewhere, were found. Volcanic rocks in abundance overlie, con-
formably, Lower Middle Jurassic fossiliferous marine strata over a large
part of Whitesail Lake map-area. Some of these volcanic rocks may reach
up into the Upper Jurassic. No Lower Cretaceous fossils equivalent to those
found elsewhere in the Hazelton group were found in the area, though they
do occur just north of it.

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