3

C.—2c

Soil Survey, Central Otago. On a later page Mr. Ferrar gives an account of the work done since the soil survey of the areas included in the Public Works irrigation schemes for Central Otago was begun last January. In some localities harmful salts, chiefly sulphates, tend to accumulate on the surface of the soil. So far as my observations went these areas are very small, and confined to places where drainage is bad, or irrigation water has been injudiciously applied. There need be no difficulty in dealing with these areas. Exact measurements of the water supplied to the lands being irrigated, and careful records of the results are very desirable. These matters are no doubt being kept in sight by the irrigation engineers. Work. Dr. J. Marwick, Palaeontologist, reports as follows : —- " During the past year I continued work on the Cretaceous and Tertiary mollusca. Collections made by the field staff were examined and identified, the chief localities being in the Nelson and Taranaki districts. The building-up of a representative collection of foreign mollusca for comparative purposes has been continued. In exchange for New Zealand fossils, the following collections were obtained : Miocene and Pliocene mollusca from Vienna Basin ; Tertiary and Recent Veneridse from the United States ; Recent mollusca from New South Wales. " In November last I visited Wairoa, northern Hawke's Bay, and collected fossils from the seacliffs about a mile west of the river-mouth. The mollusca showed that the rocks here are of Upper Miocene age, and perhaps the equivalent of the Urenui beds of Taranaki. The argillaceous sandstones and shell-beds of the Tongoio and Arapawanui valleys also provided extensive collections. The fauna is the same as that of the Petane-Ngaruroro sandstone, probably of Middle Pliocene age. " I spent five weeks of February and March in the Gisborne district, where the Taranaki Oilfields Company kindly provided travelling facilities. Attention was directed mainly to the Tertiary rocks, and a large number of fossils was collected from them. The chief localities examined were Morere, north end of Mahia Peninsula, Waingake, Waimata, Waipaoa River, Tolaga Bay, Tauwhareparae, Waiau River, and Tokomaru Bay." Publications and Reports. During the year the following official publications were issued : — " Nineteenth Annual Report (New Series) of the Geological Survey " (parliamentary paper C.-2c, 1925). Geological Bulletin No. 27 : " The Geology of the Whangarei - Bay of Islands Subdivision, Kaipara Division," by 11. T. Ferrar. Geological Bulletin No. 28 (" The Geology of the Huntly-Kawhia Subdivision, Pirongia Division "), by J. Henderson and L. I. Grange, is ready to appear, and the printing of Pateontological Bulletins Nos. 11 and 12 is in an advanced state. Geological Bulletin No. 29, " The Geology of the Egmont Subdivision, Taranaki," is also in the press. Several paleeontological papers by Dr. J. Marwick will appear in volume 56 of the " Transactions of the New Zealand Institute," which will very shortly be published. These papers are : " Tertiary and Recent Yolutidse of New Zealand " (pp. 259-303) ; " Myalinidse from the Jurassic of New Zealand " (pp. 304-6) ; " Molluscan Fauna of the Waiarekan Stage of the Oamaru Series " (pp. 307-16) ; and " New Tertiary Mollusca from North Taranaki " (pp. 317-31). " Petroliferous Areas of New Zealand," by P. G. Morgan, was published in the New Zealand Journal of Science and Technology, vol. 7, pp. 287-90 (1925). Several papers on New Zealand geology by the same writer appear in " Proceedings of the Pan-Pacific Science Congress (Australia), 1923," and descriptions of coal-measure sections in the Huntly and Kaitangata districts by J. Henderson and M. Ongley appear in " Proceedings of the Dominion Mining Conference, Dunedin, 1926." Office-work, etc. Throughout the winter and early spring of 1925 the various professional members of the Geological Survey staff were occupied in the preparation of detailed reports and studies connected therewith. During the year numerous requests for geological and other information related to the work of the Geological Survey were answered, and many samples of rocks, minerals, and fossils were examined and identified. Among specimens of interest received were diatomaceous earth from near Kamo, stibnite from Cape Brett district, vivianite from Kawakawa district, manganese ore from Ruapekapeka, inflammable gas from Raukawa West (Hawke's Bay), and phosphatic concretions from Burnside marl-pit. The draughting staff drew six maps (each covering a survey district) and one sheet of sections for photo-lithographic reproduction, besides making numerous additions and corrections to twenty-one other maps drawn in previous years. Twenty field-sheets, fourteen pantagraph reductions, and a number of tracings and small maps were made. The drawing of geological maps of the North and South Islands of New Zealand for the New Zealand and South Seas Exhibition, Dunedin, 1925-26, occupied considerable time. A fault map of New Zealand was also partly prepared. Numerous map-proofs were corrected and coloured, and many other small matters attended to.