MINERAL DEPOSITS.

Dominion, Volume 4, Issue 1233, 15 September 1911, Page 2

MINERAL DEPOSITS.

OIL AND IKON IN TARANAKL.

Tho annual report of the Now Zealand Geological Survey, presented to Parliament, contains a summary of tho more important lcaturcs of tho detailed report which Mr. E. do C. Clarke ha 3 submitted on mineral prospects in tho New Plymouth subdivision. Mr. Clarko btates, inter alia, that there is no- evideuco as to the mode of origin of tho gas or oil nor aro there any geological data which justify the selection of bore-sites. Ho mentions that oil has been found ia payable quantities on tho Tarauaki Petroleum Company's property. The oil horizons, as disclosed bv boring, lie approximately IOOOtt., 2000 it„ and 3000 ft. below sea-level, near New Plymouth, but tho strata aro ill-defined, and arc at greatly varying distances .in neighbouring bores. Tho 3000 ft. horizon is the most productive. The position of oil-reservoirs in tho sub-divisions can be determined only by systematic deep boring, lu view ot tho above conclusions, Mr. Clarko recommends— "

A thorough geological examination of the country to the E. and N.E. of tho subdivision, in tho hope thai payable oik reservoirs may there be located nearer the surface. A systematic prospecting of the subdivision* by means of deep bores at regular and considerable distances. No bora should be abandoned as "dry" unless it has reached a depth of 3000 ft. below soalcvel williout obtaining oil., Tho systematic according of strata passed through in the bores, and thokeepiug of large and accurately-labelled samples of these strata. The co-operation of all parties engaged in oil-prospecting, more especially in regard to tho comparison of the strata passed through, the only way to obtain comparablo results is to secure tho eonslant presence on the field of a competent geologist, who should examine and record all Iho specimens obtained. Speaking of iron deposits, Mr. Clarke states that from an economic standpoint; tho only iron-ores which require notico are the dep6sits of blacksand. In soino localities—e.g., in the neighbourhood of Paritutu—very large accumulations of almost pure magnetic ironsand occur. At many places, however, tho pure ironsand has been sorted by the action of the waves and the wind, so that it forms only a thin covering to a more hfttro;w«\i9 sand. )t would therefore bs adriwblo, bsforo any erection of smellinj-worka is undertaken, to carry out a thorough and exhaustive sampling of the ironsand deposits. In such examination m*re surface samples should not lie allowed lo predominate unduly, but the character of Ihe sand from various depths should be fully taken into account, Te-ta of ironsand from tho Patra district havo been latch made in the Dominion Laboratory, will" the result, inter alia, that 0.10 per cent, of vanadium was found tobe present. It is probable t)wt_ the Now Vlvmonth ironsand also contains vanadium, and, if so, it* commercial val-e as a source of sleel may be nilanly intreas-d, provided thai: not mere thon 58 per cent, of the vanadium is lest in the smelling and si eel-making processes.