Preliminary Report on the Oil locality near Moghal Kot, in the Sheráni country, Suleiman Hills, by R. D. OLDHAM, F.G.S., Deputy Superintendent, Geological Survey of India.

The petroleum which I was instructed to examine and report upon issues in several spots from a band of hard, unfossiliferous sandstone, Position of the springs. probably of a cretaceous age and about 600 feet in thickness. The most abundant springs are close to the base of this band of sandstone, where three thin bands of soft porous rock form conduits along which the oil works upwards from below. The actual points of issue are in the river-bed, and are determined by the profile of the out-crop of the oil-bearing strata. Traces of old flows and rock, blackened and impregnated with dried-up oil, are found for a height of 60 feet above the water, showing that the flow of oil has been continuous for at least the period required to deepen the gorge by 60 feet. Probably the flow has been going on for a much longer period, but at a greater height above the stream the outcrops of the porous beds are hidden by recent gravels. The oil is clear, limpid, of a pale yellow colour, and, as it issues from the rock, perfectly free from water. There is no reason for doubting that the samples examined in Calcutta by the Chemical Examiner to the Bengal Government, and in the Laboratory of the Geological Survey of India, were genuine samples of the oil as it issues from the rock; and the result of those examinations is sufficient to show the high value of the oil if it is procurable in any quantity. The actual outflow of oil at the springs is probably small, not more than 10 gallons a day at the time when I visited them. This could doubtless be increased to some extent by pits or borings, but, owing to the high angle of dip of the rocks and the consequent easy escape naturally afforded, I do not anticipate that the increased yield so obtained would repay the expense incurred. No other springs of petroleum appear to be known in this district. It is

Nature of the oil.

Strcuture at Moghal Kot.

probable that a detailed examination would show traces of oil in other localities also, but there is a special structural reason why there should be an easily recognizable oil spring at this spot. The gorge of the stream happens to cut across

B

the crest of a very open anticlinal fold whose axis dips to E N. E. at 30°, so that the oil working up from below would become concentrated along the very line where the lowest point in the outcrop of the porous beds occurs. I do not consequently attach great importance to the absence of other known occurrences of oil springs.

Anticlinal Parwara.

From Moghal Kot down to Parwara the rocks maintain a steady dip to about E. N. E., the local dips varying from N. N. E. to E. Below Parwara the dip is reversed, and between it and the plains. there is a well-defined anticlinal, whose crest lies at Dwamandi. Under this anticlinal there is probably a considerable accumulation of oil; but, so far as my observations along the line of march go, there is no bed well adapted to serve as a reservoir which would be reached at a reasonable depth.

General conclusions.

The general conclusions to be drawn from what I have seen are, that there can be no doubt of the existence of oil of excellent quality and great value in the district, but that it would be premature to undertake any expensive operations at present. It is, however, important that, as soon as the country is sufficiently settled to allow of it, a thorough and systematic exploration should be undertaken, with a view to determining whether there are any localities where it is probable that oil occurs in sufficient quantity, and at a depth which would render its profitable extraction possible.

On Mineral Oil from the Suleiman Hills, by THOMAS H. HOLLAND, A.R.C.S., F.G.S., Geological Survey of India.

A careful examination has been made in the laboratory of the specimen of oil collected by Mr. R. D. Oldham, F.G.S., at a point "one and a half miles above Moghal Kot, Choha Khel Dana, Suleiman Hills," with the following results:

The sample received was a deep yellow liquid with slight fluorescence, flocculent sediment, and a globule of water at the bottom Physical properties. of the bottle (vide page 90).

The odour of the liquid was less aromatic than that of the ordinary commercial American kerosine oil obtained in the Calcutta market.

It was mobile at the temperature of the laboratory (75° Fahr.), but began to thicken on cooling to 54° Fahr., on account of the crystallization of the heavier hydrocarbons, and completely solidified at about 32° Fahr. The specific gravity at 60° Fahr. was 0.831.

The "flashing" point, determined by means of the apparatus devised by Sir Frederick Abel and adopted as the legal standard by the Government, was found to be 128° Fahr.

Fractional distillation.

A measured quantity of the oil was subjected to fractional distillation with the following results:

The 1st fraction distilling between 166° F. and 430° F. was found, on the application of Abel's test, to have a flashing point at 70° F.; the 2nd fraction, distilling between 430° F. and 454° F., flashed at 102° F.; whilst the 3rd distillate showed no signs of inflammable vapour until the temperature of 127° F. was reached. Hydrocarbons, solid at ordinary atmospheric temperatures, distilled over plentifully with the 9th fraction, which began to deposit paraffin on cooling to 50° F. and solidified at 41° F. Of the remaining tenth 8.33 per cent. of the original volume distilled over, and deposited solid paraffin on cooling to 74° F., completely solidifying at 58° F. A quantity of matter solidified in the condenser (173 per cent. by weight), forming what is technically termed the paraffin scale,' The carbonaceous residue amounted to o'09 per cent. The total of these indicates a most unusually small proportion (o'11 per cent.) of loss, which I believe to be due to a simple modification made in the usual form of apparatus (vide page 87). From the series of specific gravity determinations of the successive fractions of the distillate, it will be seen that there is a gradual increase in the density, coincident with a deepening colour, and, so far as Sir Frederick Abel's apparatus will allow of a determination, of a gradually rising flashing point. There is, therefore, no evidence.

of the oil having "cracked" during the operation.

The quantity of oil supplied being very limited, I am unable to make any further experiments for the purpose of ascertaining the exact percentIlluminating oil. age of oil available for illuminating purposes. It is possible, however, to form a fairly accurate opinion from the facts obtained during the fractional distillation. The limit at most must be placed at 30 per cent., the heavier oils above this being unfitted for burning in the forms of apparatus at present in general use for that purpose, whilst the three fractions distilling below 480° F. would, if mixed, give a sample with a density agreeing with the American commercial oils, but with a flashing point undesirably high. In the processes adopted in metalretorts on a manufacturing scale, experiment might result in a higher yield of illuminating oil by cracking the heavier forms of liquid hydrocarbons. This seems the more probable from the large proportion of these liquid compounds, and the small quantities of solid hydrocarbons, the first eight fractions being free from these latter bodies.

Comparison with other Sheráni oils.

Compared with other samples obtained from this district, the specimen sent by Mr. Oldham must be considered to be decidedly inferior in quality.

In December, 1889, samples stated to be raw mineral oil were forwarded from Dera-Ismail-Khan by P. Broadway, Esq., District Superintendent of Police. These were separately examined by Dr. Warden, Chemical Examiner to the Bengal Government, and in the laboratory of the Geological Survey by Mr. P. Lake.

Dr. Warden found the specimen to have a specific gravity of o'8209 at 15.5° C., and a flashing point of 89° F.; and in his report concludes from his examination that the specimen was "not a crude, but a commercial kerosine oil of Russian origin.” Mr. Lake found the sample submitted to him to have a density of 0.822 and a flashing point of 89° F.

In September, 1890, Dr. Warden reported on a further specimen of mineral oil from the Sheráni country, procured by the Deputy Commissioner of Dera-IsmailKhan on the slopes of the Takht-i-Suleiman. He found it to have a specific gravity of o8154 (at 15.5° C.) and a flashing point of 84 29° F. Its density and flashing point indicate, therefore, a state of purity far superior to the sample received from vir. Oldham. A comparison of the results of fractional distillation confirms this conclusion-

A. Mineral oil procured by the Deputy Commissioner of Dera-Ismail-Khan and examined by Dr. Warden.

B. Mineral oil procured by Mr. Oldham and examined in the laboratory of the Geological Survey of India.