Societies and Academies

Abstract

LONDON. Mineralogical Society, Nov. 4 (Anniversary Meeting).—F. C. Phillips: On crystals of brookite tabular parallel to the basal plane. Small yellow-brown rectangular plates in heavy residues from Middle Jurassic sandstones of N.E. Yorkshire are shown by optical and X-ray examination to be brookite of normal optic orientation but unusual crystallographic habit, being tabular parallel to the basal plane. They are associated in the residues with brookite of normal habit, abundant anatase, and rutile.—T. Ito and T. Shiga: On scorodite from Kiura Mine, Bungo, Kiushiu, Japan. The mineral occurs as small dark-brown and green crystals associated with vivianite, fluorite, and quartz in druses in veins of arsenopyrite intruded into limestone. Chemical analysis on carefully selected material gives a result consistent with the formula FeAsO4 . 2H2O. Forms present are (001), (100), (01l), (120), (111), (201), (211), and (322). The crystals are orthorhombic with a: b: c= 0.865: 1: 0.972. The habit is pyramidal equidimensional. The 111 faces show abundant vicinal faces belonging to two principal zones {01¯} and {10¯}. W. Campbell Smith: On a new meteoric stone from Suwahib, Arabia. The stone was found in 1930 on the sand near Buwah, in Suwahib, by one of the Arabs accompanying Mr. Bertram Thomas on his journey across the Rub' al Khali. As found, it weighed just over 2381/2 gm. It is coated with limonite and shows no definite crust. It is a black chondrite belonging to Prior's Cronstad type, with more than ten per cent of nickel-iron. The density is 3.52.—Edward S. Simpson and D. G. Murray: A new side-rolite from Bencubbin, Western Australia. A mass weighing 119.5 lb. (54 kgm.) was found in 1930 near Bencubbin, about 150 miles north-east of Perth. It consists of a skeleton of nickel-iron (68.8 per cent) with enclosed crystals up to 1 cm. across, of greyish-white enstatite (13.5 per cent) and dark olivine (12.5 per cent). In the metallic portion Fe: Ni =15:1. The meteorite is classed as a mesosiderite with an unusually high proportion of nickel-iron.—A. R. Alderman: The meteorite craters at Henbury, Central Australia. The locality is known locally as the Double Punch-bowl, from the two largest adjoining craters. It is situated seven miles west-south-west of Henbury cattle station on the dry Finke river, and about fifty miles south of the McDonnell Ranges in the very centre of Australia. Within an area of 500 yd. by 500 yd. thirteen craters were mapped. The largest is oval in outline, measuring 220 yd. by 120 yd. across, and with a depth of 50–60 ft. The other craters are roughly circular, with diameters ranging from 10 yd. to 80 yd. The walls consist of powdered rock and shattered blocks of Ordovician sandstone and slaty rock. Owing to the craters acting as collecting pans for rain-water in this arid region, the spots are prominently marked by the growth of mulga trees, acacias, and coarse grass. Scattered around the craters are numerous pieces of metallic iron, usually angular in shape, and ranging from a fraction of an ounce to 521/2 lb. in weight. In one area of 6 ft. by 6 ft. more than a hundred fragments were collected. Only two masses (one of 13 lb.) were found within the crater walls; and in one of the smaller craters a borehole to a depth of 8 ft. through fine silt down to coarse rock fragments yielded no mass of iron. Fragments of iron rust are also abundant; and some glassy material, suggesting fusion of the country rock, was found. These craters, which are very similar, were evidently formed by the impact of a shower of meteoric irons at some remote period.