C/A.
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7
Location of Upper and Lower Sites. Topographical Features.
6.
The River follows a NE-8V course to within about 2,000
yards of the southern coastline, where it takes a right-angle
bend flowing to the S.E. for about 600 yards, where it again
takes a nearly right-angle bend- and follows a somewhat meandering
course to the sei The Upper site lies about 2,000 yards above
the point where the river takes the upper right-angle bend, and
the Lower site about 1,000 yards below the lower bend.
7.
These topographical features led us to the view that
the main river channel possibly follows more or less along the
line of a major fault, which would pass under a dam if constructed
at the Upper site but that this objectionable feature might not
occur at the Lower site as the major fault would possibly continue
to the sea from the upper right-angle bend following the general
trend of the valley above that point and passing under a "col"
referred to hereafter as "Col No. 1*.
Boreholes.
The boreholes which have now been sunk at the Upper and
Lower sites and at Col No. 1 confirm this view, the presence of
much shattered rock having been disclosed at the Upper site, and
rock was not reached at one point even at a depth of more than
150 feet below the surface, whereas at the Lower site no evidence
of a fault has yet been disclosed, and rock has been reached by
the boreholes
maximum depth of 61 feet below the surface.
9.
A borehole has also been sunk at Col No. 1 to a depth
of over 150 feet without reaching sound rock, which tends to
confirm the view that the major fault probably passes either under
or in close proximity to this Col.
Comparison of Upper and Lower Sites.
Upper Site.
10.
The Upper site would enable water to be impounded to a
higher level than at the Lower site by about 140 feet, and though