COMMISSION GEOLOGIOUE - arkisto.gsf.fi

On the prospecting and geology of the K emi chromite deposit, Finland 41
of the ore is N 72° E, which me ans that it deviates somewhat from that
of the West End ore. The length of the ore probed by drillings is 800 m.
The dip of the ore, obtained by connecting it in the same vertical plane in
profiles at different depths, varies between 65 and 70 degrees (NW). The
average thicknesa of the whole ore zone is slightly over 100 m. After eliminating
the more scattered portions of the ore from the foot wall aide, the
average thickness of the reduced, more unified ore is about 71 m, the range
being from 33 to 101 m. Depthwise the ore has been observed in some profiles
to narrow down and in others to broaden out. The deepest profile made of
the ore pierces it at a mean depth of about 210 m. The ore is quite dispersed
toward the foot of it. Also in the more unified hanging wall part of the ore
there occur oreless intercalations in abundance. It is not generally possible
to connect with each other these intercalations any more than the portions
rich in ore even in the case of neighboring drillholes (spaced 100 m apart).
In a typical cross-section, like the one shown in Fig. 4, there occur within
the total thickness of the occurrence, four or five parts , rich in ore divided
by barren or ore-poor rock. In all likclihood, the unified, high-percentage
zone extending throughout the length of the occurrence reappears in the
hanging wall of the ore. The thickness of this zone varies between 2 and 42
m, the me an thickness being approximately 15 m.
The mean Or 20 3-content of the Elijärvi ore zone, considering the aforementioned,
reduced thickness of 71 m, is 20.3 %. The chrome-oxide content
of the higher percentage ore zone occurring in the hanging wall is 30.9 %.
VlIANMAA ORE
Only three holes were drilled in this area, two of them in the same vertical
plane. On the basis of the geophysical interpretation it could be assumed
that the trend of the ore belt had turned more northward at this
point. This also caused a shift eastward of the drilling direction. Two holes
drilled in the same vertical plane indicated the dip of the ore as being more
gentle than in the ones described in the foregoing.
The southern hole (R 31) in the area pierced a relatively unified ore body,
the thickness ofwhich was approximately 75 m and the mean content 24.5 %
Or 2 0 3 . High chrome-oxide values occur here evenly distributed throughout
the thickness of the entire ore body.
The pair of holes (R 32, R 34) drilled farther to the north pierced an ore
body probably joined to the one referred to above, its mean thickness here
being about 68 m and mean content about 23 %.
The more eastern of the pair of holes pierced another ore zone after
passing through a bed of rock ab out a hundred meters thick; this zone
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