120 best, on the basis of present knowledge, not to include this map-unit in the Asitka group, although it is recognized that in part the two units are probably correlative. Similarly, the meagre paleontological data provide evidence for correlating at least part of this map-unit with the Cache Creek group of Permian and partly Pennsylvanian age. The relations between the Cache Creek group and either the Asitka group or the map-unit here under discussion are not known; the Cache Creek group is probably mainly younger, but the ages of all three units may overlap considerably. On the basis of their geographic position and general lithology the banded tuffs of the southern mountain group appear to be in part a continuation of some of the volcanic and sedimentary rocks that have been mapped as the lower part of the Takla group of Upper Triassic and later age in the Takla and Manson Creek map-area (Armstrong and Thurber, 1945; Armstrong, 1946b). However, the rocks of this unit in Aiken Lake map-area contain abundant fragments of corals, which are not known in the definitely Upper Triassic rocks of the map-area to the south, and do not contain the molluses typical of the Takla beds. In summary, this map-unit is thought to be entirely or almost entirely of late Paleozoic, probably mainly or entirely Carboniferous, age, and to include beds that correspond with beds of the Asitka group, and possibly also with beds of part of the Cache Creek group. CACHE CREEK GROUP DISTRIBUTION Rocks assigned to the Cache Creek group are exposed in the south- eastern part of the map-area, south of Osilinka River, east and west of Wasi Lake. A few outcrops, part of a large body of Cache Creek rocks exposed in the adjoining McConnell Creek and Takla map-areas, are found in the extreme southwest corner of the map-area, southwest of Omineca River. LirHoLoGy ROCKS IN THE SOUTHEASTERN PART OF THE AREA The Cache Creek group rocks in the southeastern part of the map-area fall into three main divisions: one predominantly massive limestone, one composed mainly of volcanic rocks, and one consisting mainly of argillite, with slate, chert, minor volcanic rocks, and limestone. The divisions are arranged from east to west in the order named. Limestone Division The dominant rock in this division is massively bedded, blue-erey weathering, light grey and dark grey limestone. Most of it is free from clastic material, finely crystalline, and of a compact uniform texture, with a smooth conchoidal fracture. In places, units up to 100 feet thick are creamy to white, buff weathering, and relatively coarsely crystalline. Some beds, best exposed on the slopes of Osilinka River Valley just east