8 
region, all the sediments then deposited must have been eroded before the 
ocean again invaded this region during the Devonian and deposited the 
Minnewanka limestones. During the long time represented by the deposi- 
tion of some 2,500 feet of calcaredhs rocks, the waters were comparatively 
shallow, for crossbedding occurs at intervals throughout the entire thick- 
ness of beds. 
The ocean was then drained from this area and remained away so 
long that when it returned not a single species of those animals so common 
in the Devonian sea returned with it; yet the beds still remained hori- 
zontal as when laid down, for the sediment distributed by the waters of 
the Lower Mississippian are conformable to the beds beneath. The land 
remained under water for an interval sufficiently long for 1,200 feet of 
black and grey calcareous muds, the Banff shale, to accumulate, and 
above them 600 feet of limestbne, the lower part of the Bundle limestone. 
That the waters were never very deep is evidenced by the persistently 
recurring crossbedding, more usually present in the coarser-grained beds. 
At times the sea bottom swarmed with bivalves of various kinds; at other 
times the condition of the sea bottom or of the water was such that during 
the deposition of hundreds of feet of limestones or calcareous shales not a 
single well-preserved shell was included. 
The ocean again retired from this region at the close of the Lower 
Mississippian and did not return until Lower Pennsylvanian time. The 
life of its shores had again almost entirely changed; a few species only of 
all those inhabiting the ocean when it covered this region in early Mississip- 
pian time returned with it in the Pennsylvanian. The sediments brought 
in by the rivers and deposited by the ocean at this time, now forming the 
upper part of the Bundle limestone, give evidence by frequent crossbedding 
that the waters were never very deep. The abundance of coral reefs 
similarly indicates shallow waters. 
That the land again emerged before the deposition of the sands form- 
ing the Bocky Mountain quartzite is indicated by the conspicuous difference 
between the fauna of the quartzite and that of the Bundle limestone, a 
difference apparently too pronounced to be accounted for only by the 
sands of the ocean bottom ahd the nearness of land. 
Again the ocean was drained from the region and did not return until 
the Triassic when it deposited the muds of the Spray Biver formation. 
During the deposition of this shale the region remained more or less con- 
tinuously under water, as marine fossils occur through its thickness. The 
presence of Lingulae apparently indicates a near-shore deposit; these 
Lingula beds are, moreover, mostly crossbedded and-ripple-marked. Mud- 
cracks are somewhat abundant, but were never found associated with 
fossils; these may indicate land conditions for a time. 
DETAILED DESCBIPTION OF SECTIONS 
Several sections were made, partly to clear up debated ground in the 
main sections and partly to include some very fossiliferous beds. The 
main section is section 2, supplemented above by the upper part of section 
1 (localities 1 to 20 inclusive). 
