13 
(2) The basal member of the Cambrian series is a well-bedded massive 
conglomerate, the well-rounded pebbles of which are composed chiefly of 
quartz and rounded pebbles of the underlying Precambrian rocks. This 
conglomerate is 600 feet thick and shows ripple-marks, and in some places 
crossbedding. 
(3) The underlying Beltian rocks are siliceous metargillites, green and 
purple in colour, and are characterized by abundant mud-cracks and 
ripple-marks, evidence of shallow-water deposition. The Cambrian shows 
rocks of marine deposition. 
(4) The Beltian rocks are well-indurated, siliceous metargillites, 
whereas the Cambrian rocks of similar nature are soft shales. 
(5) The varying thickness of siliceous metargillites of the Siyeh 
formation between the Purcell lava and the basal conglomerate of the 
Cambrian shows that erosion has permitted the Cambrian rocks to rest on 
different horizons of the Precambrian. 
RAM CREEK AREA 
The eastern trench wall from Bull river to Diorite creek which enters 
the trench from the east about 15 miles south of Canal flats, is composed 
entirely of Beltian rocks which strike in a general way north and south 
with a dip to the east. As Diorite creek is approached the strike of the 
rocks swings around to the northeast, causing the Precambrian-Cambrian 
contact, which follows the strike of the trench about 10 miles to the east, 
to intersect and appear on the trench wall (Figure 1). Satisfactory expo- 
sures do not occur on the trench wall so that a section was roughly measured 
on a high ridge at the head of Ram creek. 
The fossils listed in the following section were identified by Dr. Walcott. 
Feet Elko Limestone (Middle Cambrian) 
12 Sandy limestones and limestone (fossiliferous) 
Olenellus sp. (many fragments) 
10 Red and green paper-like shales 
13 Limestones (fossiliferous), brownish weathering with yellow shale interbands 
Hyolithes sp. (a small form that is common in the Mount Whyte formation near Field, B.C.) 
12 Limestones (fossiliferous), reddish and buff weathering 
Olenellus (fragments similar to those above) 
25 Coarse crossbedded sandstone and conglomerate (white quartz pebbles) 
18 Yellowish buff-weathering, paper-like shales 
45 Red sandstone interbedded with yellowish buff-weathering, paper-like shales 
75 Sandstone and conglomerate mostly white, some shale interbands 
75 Massive, white conglomerate (quartz pebbles) 
75 Grey and brown sandstone with shale 
45 Greyish white sandstone 
50 White quartzites and yellow shales 
20 Red shales 
600 Massive white quartzite and conglomerate (quartz pebbles) 
20 Sandstones and buff-weathering dolomites, some shales (fossiliferous) 
Waterworn minute fragments of trilobites, a species of Salterella ) T 
Olenellus fragments (Cambrian 
Wanneria sp. Several good heads occur on slabs of sandstone J ^ D ™ 
600 Massive white quartzites and conglomerate (mainly quartz pebbles) ; lower 5 feet rounded 
fragments of underlying Beltian rocks 
Disconformity or Unconformity 
1 , 000 RoosviUe Formation . Greenish grey, siliceous metargillites, some buff-weathering dolomites 
showing large concentric structures; mud-cracks abundant 
400 Phillips Formation. Interbanded red and purple metargillites, some massive and sandy, 
some thin bedded and argillaceous, some black siliceous bands, mud-cracks abundant 
1,500 Gateway Formation. Interbanded, massive, buff-weathering siliceous dolomites and yellow, 
sandy argillites showing numerous casts of salt crystals and ripple-marks 
Purcell Lava . Amygdaloidal and porphyritic in two flow's 50 feet thick 
Siyeh Formation . Section continuous down to the Aldridge formation 
