The following notes are intended to accompany Map No.1049, which has the same title as that given above. This map was prepared at the request of the Survey Directorate, L.H.Q., Melbourne, Department of the Army, and is primarily for the use of the Director of Survey, Advanced L.H.Q., Brisbane. The map is termed "provisional" since it is based on only a portion of the data available and the reductions have been made by approximate methods. Nevertheless since use has been made of that portion of the data which has been most recently observed it is considered the most reliable for most practical purposes. For some time work has been proceeding on a final map showing the distribution of magnetic inclination over Australia and the surrounding areas, and this map will be available in the near future.

On the 5th February, Mr. A. A. McLeod, General Superintendent of King Island Scheelite, N.L., telegraphed that it was desired to obtain further information about the ore structure to the north-east of cross-section line 13, and suggested the drilling of two diamond drill holes. Three possible sites and holes were discussed. In response to a request from Mr. McLeod, a visit was paid to the mine on the 26th and 27th ultimo, when returning from Mount Bischoff mine, Tasmania. The whole position regarding the above portion of the deposit and open cut were reconsidered, and problems regarding drilling further west on the northern side were also investigated. A short statement was prepared while at the mine which forms the basis of the remainder of this report.

A geological survey of the mount Bischoff Mine area was commenced in January, 1944, with the objects of delimiting the known ore shoots, determining the field relationships of those and so arriving at an understanding of ore occurrence which could be applied to the location of possible new shoots. By April the open cut area had been surveyed accurately and in detail, a general geological reconnaissance made and detailed geological mapping carried out of half of the open cut and a considerable part of the area outside the open cut. This report comprises a discussion of existing and suspected ore reserves. The report includes an assay plan and a diagram of assay sections of the Greisen orebody.

Rumbalara is a small siding on the Adelaide-Alice Springs railway line. It is about 120 miles by rail and 143 miles by road south of Alice Springs. The mine is 35 miles by road northeast of the siding. The object of the visit was to determine, if possible, the extent of the deposits and to decide whether they are likely to be able to supply the requirements of the Australian paint industry, particularly during the present war. The period 29th July to 2nd August, 1943, was spent in the field. During this time a plane table survey was made of the deposit and its environs. The underground workings were surveyed by chain and compass. Half a day was also spent at the field on the 18th January, 1944, in collecting specimens and making a brief inspection of new workings.

This sample of bryozoal marl from Montagu, Tasmania, was collected by Mr. F. Canavan. It contains a faunal assemblage typical of the Balcombian Stage of the Middle Miocene as found in Victoria and can be referred to Longford substage of the Balcombian.

At least as early as 1940, it was realised by the Department of the Interior that the reserves of suitable rock (shale or slate) in the pit adjacent to the Canberra Brickworks were limited. A decision was made to find a temporary site to provide sufficient material to supply the brickworks for two years. A site at Deakin, 1700 yards by road east from the existing brickworks was selected and was recommended by Dr. W.G. Woolnough in 1940 as suitable, subject to testing by costeans and pits. A survey of the area in the subdivision of Deakin, Canberra City Area, was then arranged and was made during March and April, 1944, the object being to determine if there were sufficient reserves of suitable material to supply the Canberra brickworks for a period of not less than two years. This report describes the results of this survey.

These investigations were carried out at the request of the Secretary for the Navy. The following report is intended to confirm provisional information made available to naval personnel during and at the conclusion of the surveys. The Fremantle Degaussing Range is situated in Gage Roads near Fremantle Harbour. The position of the coils forming shallow and deep ranges is shown in Fig. 1. Deperming operations were carried out in Careening Cove, Garden Island. The objects of the investigation were twofold. First, to determine the average normal values of the vertical (Z) and horizontal (H) force components of the Earth's magnetic field in that part of the harbour which would be occupied by a ship in passing over the coils, and second, to determine the average normal values of Z and H in the vicinity of Careening Cove, Garden Island.

The area was visited in company with Mr. R.S. Matheson of the Geological Survey of Australia in December, 1942, when eleven pigmatite bodies bearing mica and beryl were examined. The report furnished after that visit (1943/2), gives details of access, topography, climate and vegetation which are not repeated here. In view of the urgent demand in Australia for "strategic" mica, i.e. mica of quality equivalent to Clear and Commercial-clear, it was recommended that one deposit at Yinnietharra should be opened and prospecting of others carried on simultaneously. As a result of these recommendations, the Deputy Controller of Mineral Production started mining operations on the selected dyke by open-cutting in June, 1943. Although it was stressed in the abovementioned report that poor exposure of the dyke, on which there were no workings, rendered any estimate of the probable yield of marketable mica speculative, the results actually obtained were far below expectations, and a heavy financial loss on the project was incurred. Consequently, while the question of abandoning the mine was under consideration, a detailed examination of the workings was carried out in June, 1944, again in the company of Mr. Matheson, and the results of this investigation, which was not wholly confined to geological aspects, are embodied in the present report.

Gibsonvale tin field is situated approximately three miles southeast of the village of Kikoira. This preliminary report was prepared following an examination of the tin field by the writer. Aspects of the general and economic geology of the field are discussed herein.

The testing programme described herein is the result of a recommendation made in a previous report. Twenty-four boreholes were put down during October, 1944, to determine the extent and quality of the bentonite and associated clays. During the early part of the boring campaign the area was surveyed in detail by plane-table with the assistance of the Queensland Geological Survey. The details and results of boring, origin of the bentonite, micro-fossil content, testing, and reserves are discussed in this report. Logs of Boreholes, a plan of the bentonite deposit, and cross section diagrams are included in the report.