Bassetite and uranospathite Were described as new uranium minerals from Cornwall in 1915 by A. F. Hallimond, to whose paper reference should be made to supplement the descriptions given here. The position of both minerals as relatives of autunite was recognized by Hallimond. Unfortunately, chemical analyses could not be obtained and the composition of these minerals has remained uncertain. No further information has been published about uranospathite. In 1940 Meixner reported that microchemical tests of an apparently authentic specimen of bassetite from Cornwall indicated that the mineral was a hydrated iron uranyl phosphate.

The association of orthoclase and microcline in the same rock has been commented on by many writers, and from these occurrences attempts have been made to deduce the relative stability of these two low-temperature forms of potash-felspar. Ahnost all investigators have concluded that nlicrocline is the lower-temperature modification, but difficulties in explaining the relationship of adutaria to orthoclase and microcline have been encountered.

The identification of the monoclinie potash-felspar in association with microcline is almost always based on optical properties, viz. straight extinction in the zone [010] or the absence of visible multiple twinning.

A limited amount of careful optical work has been carried out on X three analysed felspars of gabbros belonging to the main layered series of the Skaergaard intrusion, east Greenland (Wager and Deer, 1939). The work was begun with the intention of providing precise optical data to be used in further defining the relationship between composition and optics. The primary precipitate felspar crystals, hitherto thought to be devoid of zoning, were found, however, to possess a zoning which prevents the data being used in this way.

The Beaver Bay diabase forms an irregular sill-like intrusion about 3000 feet in thickness exposed over a distance of approximately six miles from Split Rock to Beaver Bay on the north shore of Lake Superior, Minnesota. It is intrusive into the Keeweenaw volcanic series above the Duluth gabbro to which it is almost certainly related. It is the largest of many such sills in this region and includes several petrographic facies grading from troctolite, through olivine-gabbro, normal gabbro, and ferrogabbro to red granite.

Some years ago a few small grains of an unknown mineral were separated by F. H. Stewart from well cuttings from the Permian lower evaporite bed of the Eskdale no. 2 borehole, sunk by the D'Arcy Exploration Company near Aislaby, north Yorkshire. The mineral (not then identified) was mentioned in an account of the mineralogy of this evaporite bed (Stewart, 1949, p. 626). Flame tests suggested that boron and strontium were present, and this was confirmed by Dr. R. L. Mitchell of the Macaulay Institute for Soil Research in Aberdeen, who, by spectrographic work, found that these were the main constituents, and that very much smaller quantities of Ca, Mg, Ba, Na, and K were present.

Many of the Dalradian and 'Moine' rocks of Donegal, and the Caledonian granites associated with them, have been shown to bear structural and petrographic resemblance to the rocks of similar age in Scotland. In Scotland riebeckite-bearing minor intrusions occur at many localities and include Ordovician, Caledonian, Carboniferous, and Tertiary intrusions. There appears to be no record of analogous rocks containing sodic amphiboles occurring in situ in NW. Ireland. The purpose of this paper is to record the existence of two small intrusions of such rocks in western Cloghaneely, Co. Donegal.

About twelve miles south-east of Burghersdorp in the Cape Province, South Africa, the unusual clay reported in this paper was first discovered on the farms 'Groenvlei' and 'Kuilfontein'. Later deposits were also uncovered on the farms 'Kapokkraal' and 'Kleinhoek'.

The clay-mineral appears to be of a very unusual type, namely, a regular mixed-layer clay-mineral (1:1 hydrous mica and montmorillonite). The mode of origin of the clay is also of interest in that it appears to be produced from a shale by hydrothermal alteration, due to intrusion of dolerite sheets.