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The penological investigation of the metamorphic and intrusive rocks of the Wakaia Subdivision has been continued, and it is now possible to state that the greywackes and schistose rocks of this area can be subdivided into three subzones of the chlorite zone —viz., Chi. 1, Chi. 2, and Chi. 3. Further mapping and collecting were carried out in this area during February and March, and this work has shown that granophyres are very plentifully distributed throughout the Otama pluton. Work on the rocks of this region is temporarily suspended pending the cutting of thin sections. While in the field this year, extensive collections were made from the conglomerates at the base of the Clinton Series at a point eight chains west from Popotunua Hill (60 chains north-west from the Clinton Railway-station), and at Albert's Cap, one mile east of Waiwera Railway-station. A study of these boulders has been commenced. Collections were also made from a small intrusion mapped by Mr. M. Ongley (1939) during a survey of the Kaitangata - Green Island Subdivision. This intrusion, situated three miles and a half south-south-west of Balclutha, is composed entirely of granophyre. A suite of the lavas from Timaru and surrounding districts was collected for the museum, at the beginning of this year. With Dr. F. J. Turner, the occurrence was investigated of some very coarsely porphyroblasic schists outcropping in a deep meander of the Waikouaiti River, about twenty-five miles north of Dunedin. During the examination of the Western Otago schists the occurrence was observed of native copper in a biotite-bearing green schist from Nevis Bluff, Kawarau Survey District. After completing field-work at Otama this locality was visited and some sampling of the green-schist zone at Nevis Bluff was carried out. Thin section information and analytical data are not yet available. Mr. R. W. Willett forwarded samples of beach sand and Tertiary sandstones from Lake Manapouri for investigation of the heavy minerals, with special reference to cassiterite. Heavy residues were prepared, but cassiterite could not be identified with certainty in any of the preparations. Analytical data is not yet available. In company with an officer of the Department of Housing Construction, possible dam-sites on the eastern side of the Hutt Valley, opposite Taita were visited. The proposed sites were situated on spurs, at a point where they flattened out considerably before dropping steeply towards the valleyfloor. The country rock is much shattered and closely-jointed greywacke and is covered by a very deep mantle of weathering products. At present, work is being carried out with a view to finding ways of utilizing glauconitic greensands as a source of potash and as a potash fertilizer. So far it has been found that electromagnetic methods may be used to produce a9O per cent, to 95 per cent, glauconite product. Qualitative experimental work has shown that, on roasting and subsequent treatment with 1 per cent, hydrochloric acid, considerable potash can be obtained from glauconite. Several pure glauconite samples are being separated from greensands for complete chemical analysis. Routine determinations of rock and mineral specimens forwarded to the Survey Office have occupied a considerable time. Several requests have been made for representative collections of New Zealand rocks and minerals, two of these coming from America, one from England, and two from New Zealand. Some time has been spent packing the type material at present available. GEOPHYSICAL WORK AT DAM-SITES, WAIKATO RIVER. By N. Modbiniak. Geophysical work at the Karapiro dam-site, on the Waikato River, a few miles upstream from Cambridge, was begun in December, 1939, and finished in February, 1940. Seismic refraction and electric potential drop-ratio methods were used. The basal rock, greywacke probably of Mesozoic age, outcrops in the river-bed, but deposits of pumiceous silt, sand, and gravel conceal it on the banks. The object of the survey was to determine the thickness of this drift at and near the dam-site. In addition, along several traverses the depth to which the greywacke is weathered and the approximate position of shear planes were ascertained. At Ohakuri, near Atiamuri, work has been proceeding for some time, and is now well advanced. GEOPHYSICAL WORK AT OREPUKI.. By 11. W. Wellman. Geophysical work at Orepuki was begun in December and continued till March. The seismic refraction method was used, but as the thickness of strata was more than expected and beyond the capacity of the apparatus available, a magnetic survey was also carried out. The Tertiary beds containing the shale near their base rest on a complex of basic igneous rocks, and by means of changes in the magnetic intensity at the surface a rough idea of the shape of the shale basin was obtained. Geological data and seismic lines near the edge of the basin confirmed the results. These, however, must be checked by extensive boring to prove the depth of the basin and the thickness of the seam of shale. ALPINE MINE, LYELL. By J. Henderson. In November, 1939, the writer, with Messrs. G. W. Lowes, and E. Collier, of the Mines Department, and H. E. Fyfe, of the Geological Survey, examined the adits driven on Reid's Reef, and inspected the greater part of No. 7 adit of the Alpine Mine. As the report will be published later, it is enough to state here that the Alpine lode appears to be in a fissure on the axial plane of an anticlinal structure, and that a study of the available reports and plans do not suggest that the ore-shoot was faulted, but rather that the ore decreased in value in depth.

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