'File 35/64 III Minerals in Oman. Madrasai geologists' researches' [‎18r] (44/276)

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One of the 10 samples cakes beautifully, the rest do not cake. At a
Probably cak- first glance the coal might be taken, for a non-caking coal,
tng coal. but this is by no means certain, nor even probable. It is
known that some coals lose their caking properties after having been exposed
to weathering. As mentioned above, the Sur coal samples were weathered,
and as there is one among them that cakes, it seems very likely that the coal
was originally a caking coal, but has for the most part lost its caking properties
by weathering.
The average specific gravity of Sur coal is 1*338. A ton of this coal^ there-
26-7 cubic feet fore, contains 26 '7 cubic feet. The specific gravity is somewhat
= i ton. higher than in Cherrapunji coal* (Assam). In Phillips's list of
43 assays of British coals, I can find only two which have a higher specific
gravity. ,
Welsh coal. Hill's Plymouth Works, s.g. 1*35.
Lancashire coal, Ince Hall, Pemberton Yard, s.g. 1*348.
Sur coal crumbles easily, and the samples fell partly to dust on the trans-
Friability. port to Calcutta.
Priability of coals may be due to mechanical pressure or to weathering.
As the Sur coal has undergone practically no pressure, the beds including it
being but slightly raised, its friability may safely be attributed to weathering.
The Sur coal will, I suppose when freshly raised from below the surface, be of
medium hardness, but it will no doubt deteriorate more or less rapidly by
keeping.
The friability of the coal is hardly a great disadvantage. I have been
informed by experienced businessmen that the market value of coal is not
affected by its more or less crumbly condition, as the gratings can easily be
adjusted. I have further satisfied myself by an inspection of Assam coal
depots at Garden Reach near Calcutta that Assam coal, which is used advan
tageously in ocean-going steamers and sells in Calcutta at Its. 17 a ton, is of a
very crumbly condition. I, therefore, suppose that the fabrication of briquettes
(" patent fuel") will not be necessary.
As to the distribution of the coal and the amount of workable coal
Total quan- available but little information could be gained,
tity of coal not
ascertained.
I have shown above that at the outcrop described the coal dips under the
surface in one direction (N.E.), while it disappears towards the other (S.W.).
Opposite the outcrop, at the N.W. bank of the ravine, no trace of coal
was found, which in the absence of other reasons must be attributed to the
coal thinning out and disappearing towards N.W. There is, however, an
indication of the coal seam extending towards S.E. In a second ravine,
running parallel with the one described, and at least one hundred yards further
S.E., traces of coal were found, which I am convinced belong to the same
seam. At the S.E. bank of this ravine, the carbonaceous shales were
noticed, and by digging away the debris I could ascertain that they are at
least of the same thickness, if not thicker than at the coal exposure. Un
fortunately the coal, which must lie below these shales, was not reached, as my
work was interrupted by the natives, but traces of coal were found in the
ravine itself below some boulders.
The evidence gained as to the distribution of the seam examined can be
summarised as follows :—
There is a workable seam of coal which from the exposure thins out
towards S.W. and N.W., but continues at least a .hundred yards towards S.E.
The seam further must continue for some distance towards N.E., as there is no
indication of its thinning out in this direction.
* LaTouche Eecords, XXII, page 169.