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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.

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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.

Species belonging to the superfamily Orthotetacea Williams form an important part of the Permian marine faunas of Western Australia. Four genera-Streptorhynchus King, Kiangsiella Chao, Derbyia Waagen,and PermoTthotetes gen. nov.-are represented. Twenty-one species are described and at least two others are indicated by incomplete collections. Many species appear to be restricted in range and are useful in stratigraphical correlation. The group of strophomenoid brachiopods now known as the superfamily Orthotetacea Williams 1953 has been for many years of interest to brachiopod students. Representative species are widely distributed throughout the world. The group attains its acme in the Upper Palaeozoic, particularly in Upper Carboniferous and Permian time. Six species only have hitherto been recorded in the Permian of Australia. One species has been described from the Permian of Eastern Australia-Streptorhynchus pelicanensis Fletcher, originally described by Etheridge in 1892 as Orthotetes senilis, from Queensland. Streptorhynchus perfidiabadensis (Etheridge) occurs at Treachery Bay, Northern Territory. Two species of Streptorhynchus and a Derbyia-like form were described from the Permian of Western Australia by Hosking (1932). In recent years extensive field work by geologists of the Bureau of Mineral Resources and of the University of Western Australia has added greatly to knowledge of the Western Australian Palaeozoic rocks and has augmented collections considerably. The Orthotetacea are now seen to be abundantly represented in Western Australia and are of considerable stratigraphical value. Four genera with at least 23 species can be distinguished in the Permian. The genus Schuchertella is known in the Devonian of the Fitzroy Basin and in the Lower Carboniferous Laurel Beds of the Fitzroy Basin. Schellwienella has lately been recognized in the Lower Carboniferous Septimus Limestone of the Bonaparte Gulf Basin and in the Lower Carboniferous Moogooree Limestone of the Carnarvon Basin. Schellwienella and an unidentified genus are present in the Carboniferous Weaber Group of the Bonaparte Gulf Basin of the Northern Territory.

The main purpose of this paper is to describe the morphology of a single genus of trilobite (Redlichia) and to discuss, and settle, the uncertainties of its stratigraphical and geographical distribution. Redlichia is the nominate genus of a family and a superfamily (suborder) and is consequently of paramount taxonomic significance. It is in its general organization related to the olenellids, but differs from them, as do the majority of trilobites, in having well-developed cephalic sutures. This paper was originally prepared in 1950-52; subsequently additions have been made in an attempt to exploit the wealth of new information published on trilobites between 1953 and 1957.