A comparison between the accessory minerals of some eastern British Columbia intrusive rocks and those of some Upper Cretaceous sandstones of the Alberta foothills region, shows some remarkable similarities in types.

Many unstable mineral constituents which occur in the sediments suggest relative proximity to the source of these minerals. They also suggest that chemical weathering was slight and that deposition and burial of the sediments were rapid.

The source of the Upper Cretaceous sediments appears to have been the area to the west of the Alberta foothills region. The rocks which supplied these sediments were mainly pre-existing sediments, metamorphic and igneous rocks, probably in this order of importance.

The absence of a substantial break in mineral type within the Upper Cretaceous sandstones, sugest that some of these British Columbia intrusives were unroofed prior to Upper Cretaceous time.

Age dating of zircon from the Nelson batholith of southeastern British Columbia indicates this pluton was intruded during late Paleozoic time.

End_of_Record - Last_Page 770-------