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The Maranboy Tin-field is situated 40 miles south-east of the township of Katherine, in the Northern Territory of Australia. The field is in a small inlier of Lower Proterozoic sediments surrounded by unmineralized sediments of Cambrian and Cretaceous age. The ore mineral is cassiterite, which occurs in fine-grained quartz-tourmaline fissure-lodes. The lodes are infillings of a conjugate system of shear fractures which strike at 110° and 160°. Available production figures from the field show that from 1915 to 1952, 49,314 long tons of ore were won, from which tin oxide concentrates containing 800.57 long tons of tin were recovered, giving an average grade (by recovery) of 1.66 per cent. Sn. A detailed assessment of the field has shown that of the numerous cassiterite bearing lodes only three can be considered as likely to yield large tonnages of ore in the future. These are the Main Lode, Stannum King Lode, and Cosmopolitan Lode. The data obtained from detailed mapping, sampling, and production records show that they may contain an aggregate of 2,767 tons of ore, assaying 1.23 per cent Sn, per foot of depth. Selective mining by small operators would, as it has in the past, raise the grade with a concomitant reduction in the aggregate of tons of ore per foot of depth. The continued life of the field is dependent upon testing the probable continuance or repetition of ore-shoot at depth, the institution of more efficient mining methods, and the provision of adequate and efficient milling facilities.

One hundred and six species of Permian foraminifera belonging to fortysix genera are discussed. Four new genera, Sacculinella, Hyperamminita, Pseudohyperammina, and Giraliarella are named, all belonging to the group of arenaceous foraminifera. Fifty-two new species are described. They include eighteen from the family Lagenidae. Since the publication of Foraminifera in the Permian Rocks of Australia (Crespin, 1947), Permian stratigraphy throughout the continent has received considerable attention from geologists engaged primarily in the search for oil and coal, but the only further publications on foraminifera have been by Crespin and Belford (1957) and Ludbrook (1957). Many stratigraphical sections have been closely studied, and the results of this work have led to the re-organization of ideas on the age and stratigraphical position of certain formations. In particular the Permian sequence in Western Australia has been mapped in some detail by geologists of the Bureau of Mineral Resources, oil companies, and the University of Western Australia, and large numbers or specimens have been examined by the author from both surface and subsurface sequences. In New South Wales, both coal and oil search have proved sources of prolific subsurface microfaunas in the Permian rocks. Surface mapping in the Hunter River area has also yielded good as assemblages of arenaceous foraminifera. Investigations in Western Australia revealed that the beds from which Ohapman and Parr (1937) described fusulinids (Neoschwagerina and Verbeekina) are not Permian but Triassic, and that the fusulinids are probably fish remains (Brunnschweiler, 1954). No rocks from New Guinea have been examined during the present work; two genera of Permian foraminifera (Pachypholia and Geinitzina) ,have been recorded from a limestone near Kuta, in the 'Western Highlands (Glaessner et al., 1950; Rickwood, 1955). Nearly all the species; included below have been studied by myself. Some I have been unable to examine personally; they are included, for completeness sake, but are described, if at all, by quotations from the original authors. During the preparation of this Bulletin, Dr. P. J. Coleman, Geology Department, University of Sydney, handed me an unfinished and undated manuscript by the late W. J. Parr and H. J. Ward on the Permian Foraminifera of the Callytharra Limestone , Western Australia. Coleman has not been able to find the specimens described in that paper; but from some of the descriptions it would seem that certain new species described in this Bulletin ,were recognized by Parr. Where it has been possible to recognize these forms, Parr's comments on them have been incorporated in the description of species.

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These documents have been scanned by the GA Library. Please refer to the document for contents.

These documents have been scanned by the GA Library. Please refer to the document for contents.

These documents have been scanned by the GA Library. Please refer to the document for contents.