'THE GEOLOGY AND MINERAL RESOURCES OF DHUFAR PROVINCE, MUSCAT AND OMAN' [‎37r] (63/96)

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The calorific value of one of von Krafit’s samples gave no
i ess than 7,846 calories or 14,122 B.T.U.’s. The strata are said
t0 be of Miocene age at the top of a 6,000-foot series of lime-
stones at the base of which Nummulites occur. The ratio of volatile
matter to fixed carbon is suggestive of the Gondwana (Permian)
coals of India, and I should doubt the Miocene age of these seams.
However, Oldham is supposed to have found the seams irregular and
thought the distance to Khor Jerama (near Ras al Hadd) too far and
difficult at that time for the development of the Sur or Fisao. valley
coalfield. Nearly 50 years have passed since his visit and it might be
worth re-examination now. The high grade of the samples, both
Oldham’s and von Krafft’s, is evident and the calorific value is
exceptionally high.
Copper Ore
81. I saw no sample of copper ore from any locality in Dhufar
nrovince but mention must be made of the copper ore occurrences,
mcluding old workings, in Masira island. These deposits were drawn
attention to by H. J. Carter a century ago. The material met with
was the ‘blue’ and ‘green’ carbonate of copper, which occurs in
decomposed hornblendic rock (presumably of the Setnail Igneous
series) No sulphide 6 re was encountered, so that the mining opera-
tions may have been conducted only with a view to obtaining easily
smelted o're without much trouble. As the deposits have been lying
idle for 100 years it is possible they may have been forgotten. They
cannot be considered as useless until the sulphide ore beneath
been tested and found unsatisfactory.
Doeomite
Two samples of ‘chalky ’ limestone which I collected from be<k,
q and 20 feet thick respectively, and lying practically horizontal,
in raline exposures south-west of Hanun, have yielded the following
results: - 3 -foot bed.
53-66%
Calcium carbonate ..
Calcium sulphate
Magnesium carbonate
Insolubles, Silica, etc.
Oxide of iron
Alumina ..
Alkalies, etc.
0 - 02 %
45-14%
0-34%
0-26%
0-08%
0-50%
10 -foot bed.
53-41%
0 - 20 %
44-69%
1-06%
0 - 20 %
0-08%
0-36%
100 - 00 % 100 - 00 %
Since the composition of pu^
bonate (30-4% lime) and 45-65/„ magnesia
47