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46
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DIAMONDS.
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this
latter contains large and small rounded boulders of sandstone, possibly
the remains of masses fallen from the retreating cliff of the Rewah
ridge ; its thickness is very variable, from two to twelve feet, due to
the uneven surface of the subjacent rock; pebbles of the laterite iron
ore are common along the bottom of the boulder bed.
The top three feet of the hard rock looks more like a reconstruction of materials than a rock in situ. It
is an irregular streaked mass of clay, with occasional strings of
broken grit bands; the crushing action which is so manifest in these
upper layers extends itself to those below ; contortion and fracture on
a small scale are evident throughout, &c. &c.
These
appearances are considered to be due to the falling of heavy masses of
rock from the cliff face, which formerly existed, as it was undermined
from below.
In
the Parma mines, although the diamond seam is deeper than elsewhere,
owing to the broken nature of the overlying strata, it is not reached
by a shaft, but the miners go to the immense labour of excavating great
pits, 25 feet in diameter and often over 30 feet deep, for the sake of
the small patch of diamond conglomerate thus uncovered.*
KUMEREA OR KAHMURA.
This
locality, which is situated to the east of Panna, was visited by Mr.
Hacket, who describes it as follows. Here the matrix, locally called Kakru, is—
A
conglomeratic sandstone made up of pebbles, one-eighth to one-half inch
diameter, imbedded in a rather fine matrix which also includes clay
galls. The lower Rewah sandstone here stretches out a considerable dis-
* Vide infra, p. 53.
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