33 ee a eee ee ee SS SSSSSNSS90909090.EEE Era Paleozoic and possibly Proterozoic Proterozoic Period or Epoch Includes Lower Cambrian beds Probably late Proterozoic Formation and thickness (feet) Intrusive contact Ingenika group +18,000 Possible erosion interval Tenakihi group +13,000 Lithology Quartz-chlorite schist, crystalline Jime- stone, sericite schist quartzite, quart- zitic conglomerate, slate, phyllite, chloritoid schist, tourmaline-zoisite schist. Part, in- cluded in Wolverine complex, altered to feldspathic quart- zite, quartz-mica- feldspar gneiss, mig- matite, leucogran- ite, silicated marble, skarn, and amphi- bolite Quartz-mica schist, quartzite, quartz- mica-feldspar schist, garnetiferous schist, cyanite, and staurolite schist. Part, included in the Wolverine complex, altered to felds- pathic quartzite and quartz-mica- feldspar gneiss Post-Lower Cambrian; may be Tertiary Post-Lower Cambrian Feldspar porphyry, granophyre, dacite Diorite(?) porphyry, altered to chlorite- sericite-carbonate rock; andesite(?) TENAKIHI GROUP! NAME AND DISTRIBUTION The oldest recognized rocks within Aiken Lake map-area consist of interbedded quartz-mica schists, micaceous quartzites, and quartzites exposed in an irregular belt 4 to 8 miles wide extending diagonally across 1 This group was first named the Ruby group in the preliminary account of Aiken Lake map-area by Armstrong and Roots (1948), but it has seemed best, in the interests of conventional formational nomenclature, to rename it after the range of mountains in which it is typically exposed. 78609—43