Beacon Series - Ferrar Dolerites

Rocks of Upper Paleozoic age, correlative with units named by expeditions working north of the Koettlitz area, form the high scarp at the western margin of the area studied. Owing to their elevation and remoteness from the coast they were not a principal target of the current study. However, the contact of these rocks with metamorphics of the basement complex was reached at two localities, both at elevations above 8,000 feet. There were no visible contact effects of the lowermost dolerite sill where it rests on basement quartzite, although specimens collected for petrographic analysis may reveal their existence. The basal Beacon is a medium-grained arkosic sandstone. Some evidence was found for the presence of a major unconformity a few hundred feet above the base of this series.