92 
THIRTEENTH REPORT. 
the centre of the basin, indicating that the influence was one felt chiefly 
along shore. 
The silication is not so difficult to account for. In part it is from 
the same source without doubt. But when it is observed that the most 
heavily silicated spots are on the shoulders of the Malden Valley where 
it expands into the basin, and also directly in line with the slight wash 
from the inflow of the valley, the chief cause of silication has been 
identified. The valley itself has felt none of these influences to any 
percepti bl e degree. 
Should it be that the magnesian influence was due to the sea, then 
it follows that Silurian conditions prevailed northward, westward and 
to the northeast whilst the Malden Valiev communicated with a sea 
«/ 
to the south in which Devonian conditions had alreadv become estab- 
«/ 
lished. • 
A N. x N. NW. to S. x S. SE. Cross Section shows the same basin 
formation, with No. “8” test hole as centre, four tests to the southeast- 
ward of it and two to the northwestward. (In no case has the west 
side been tested out to the same extent as the rest of the area, because 
of heavily increased depth of boulder till.) 
The test holes of this cross section are, in order from S. x S. SE. to 
N. x N. NW., Nos. 15, 17, 22, “9,” “8,” “4” and “5.” The distances 
between, in same order, approximately 1,000', 450', 425', 525', 
1,725', and 330'. 
Anderdon at 15, 0' 
Anderdon at 17, 5' 6", 
Anderdon at 22, 23' 6". 
Anderdon at “9,” 42' 0", 
Anderdon at “8,” 28' 0", 
Anderdon at “4,” 11/ 3", 
Anderdon at “5,” S' 6". 
Modified Anderdon at 15, 0' 0", 
Modified Anderdon at 17, 22' 1", 
Modified Anderdon at 22, 22' 10", 
Modified Anderdon at “9” 9' 0", 
Modified Anderdon at “S” 23' 6", 
Modified Anderdon at “4” 29' 4" 
Modified Anderdon at “5” 27' 0". 
Transitional Rock at 15, 3' 8", 
Transitional Rock at 17, 10' 6", 
Transitional Rock at 22, 4' 6" -f-, 
Transitional Rock at “9” 8' 0", 
Transitional Rock at “8” 11' 6", 
Transitional Rock at “4” 4' 8", 
Transitional Rock at “5” Not penetrated. 
The Anderdon shows distinctly the basin shape of deposit. On com- 
paring the Anderdon + Modified Anderdon depths in No. “8” and No. 
“9,” it will be noted that No. “9” has felt the deteriorating influences 
much less than the No. “8” area. It shows less Modified Anderdon 
and more high-grade limestone. Consequently, whether at base or sur- 
