C.-9

26

' dry " on the resumption of boring, seems a little extraordinary, and it is not surprising that many are inclined to question the genuineness of this " blow-out." The " log " of this bore is given in a paper on " The Oil Prospects of Poverty Bay and District," by Mr. H. Hill,* and the rocks passed through appear to be claystone and fossiliferous sandstone—that is, the upper portion of the Whatatutu Series. Indications of oil, it is stated, were obtained in this hole in " sand-bands " at depths 470 ft. to 483 ft., and from 793 ft. to 900 ft. Theoretically, the choice of the position of this borehole was unfortunate, since the hole is located almost in the trough of a syncline. The Minerva borehole, commenced in 1888, is situated on the left or eastern bank of the Waipaoa River, distant five miles (air-line) south-west of Waitangi Hill. Very little information is available concerning this hole, but it is said to have reached a depth of about 800 ft. At a depth of 700 ft. gas emanated freely, and when caused to issue through a 1 in. pipe burned continuously with a flame over 2 ft. in length. At 750 ft. a red shale impregnated with oil was struck, f This hole is situated about one mile to the south of the crest of the anticline already described as passing through Waitangi Hill. Various small gas-emanations occur in the subdivision, which in all cases appear to be either on lines of faulting or on breaks produced by slumping. It is probable that some of these emanations are due to the decay of vegetable matter but a short distance below the surface. The following are results of analyses of samples of oil obtained from the springs at Waitangi Hill. Nos. 2 and 3 are from the main oil spring, while No. 1 is from a test pit sunk about 3 chains distant from the main spring : — (10 (2.) (3.) Water .. .. .. .. 0-3 0-2 Nil Oils distilling below 150° C. (benzine, &c.) 0-2 0-5 Nil Oils distilling between 150° and 300° (burning-oil) .. .. .. 41-0 39-0 47-2 S.G. 0-8459 S.G. 0-8344 S.G. 0-836 Residual oil distilling above 300° (lubri-cating-oils, paraffin, &c.).. .. 5-85 60-3 52-8 S.G. 0-9107 S.G. 0-9002 From these analyses it will be seen that the oil contains an average of over 40 per cent, of burningoils and a large percentage of lubricating-oils. On account of the moderately, large percentage of burning-oils the crude product is of special importance, since it can in certain cases be used for heating purposes without any refinement. From the geological examination of this subdivision, which has just been completed, it would appear that the petroleum-bearing stratum is nowhere exposed at the surface. The petroleum showing on the springs is probably derived from a stratum considerably below the surface at this point, and makes its way to the surface by rising up a " break "or fault-plane. The fact that the oil indications show on the same line for a distance of 16 chains in itself suggests that they are on a line of fault. The depth at which the petroleum-bearing stratum occurs can only be a matter of speculation until some information as to the nature of the strata underlying the lowest beds exposed on the surface .in the area examined has been obtained by deep boring. It is therefore essential for the future prospects of a petroleum industry for Poverty Bay that a full and true record should be kept of the operations now in progress. Gold. —Some prospecting for gold has been done in this area, especially while the greater portion was still covered with native bush. Small pieces of quartz carrying gold are reported to have been found, but from the nature of the geological formations of the subdivision, it seems likely that these specimens have their parent veins in other districts. It is highly improbable that any auriferous quartz veins will be found in this area. The one possibility of gold being found is as alluvial gold in the conglomerate bands described above (see page 24). The chances here even are very slender indeed, since such pieces of quartz as have been seen that were included in the conglomerate are of a decidedly " hungry " appearance, and " dish " prospects taken from the bands gave not a " colour "of gold. Coal. —No evidence of the occurrence of payable coal-seams was obtained during the survey of the area. If such do occur, it is below the formations which appear at the surface, and their presence will probably only be detected by deep boring. A sample of lignite within the area was submitted for analysis, but is of very poor quality, and contains an excessive amount of ash. Material for macadamising Roads.—Of the rock formations exposed in the area, the most suitable for macadamising-material is the conglomerate described under the heading of General Geology. This material is sufficiently hard to resist crushing under traffic, and the dust formed by its abrasion, when moistened, will form a cementing medium for the larger chunks of stone. The conglomerate bands contain material ranging from fine gravel to stones of 3 ft. and up to 5 ft. in diameter. The localities of occurrence have been described under General Geology. The most accessible of these is that in the Waikohu Valley ; but, unless further investigation should prove the .existence of more bands of coarse material than were observed in the river-bed, the supply here is but small. At Conglomerate Stream is the most suitable deposit to supply a large quantity of material. Brickmaking.—Samples of clays taken from the surface bores at Waitangi Hill were submitted for analysis in order to ascertain their value for brickmaking. Though the clays contain too much iron-oxide to be of value for fine pottery-making or fireclays, they should be suitable for brickmaking.

* Trans. N.Z. Inst., Vol. xxi, 1888, pp. 320-25. 1901, p. 2.

f Article by Mr. Ackroyd, Poverty Bay Herald, May 4,