IN the Geological Magazine for February, 1919 (pp. 59–64), one of the present writers, in collaboration with W. E. Alkins, described an exposure of a quartzose conglomerate on the north-west flank of Caldon Low. The conclusions arrived at in that paper were adversely criticized by F. Barke, Wheelton Hind, and A. Scott in a later paper in the same Magazine. These writers maintain that the conglomerate was not a contemporaneous deposit, but an assemblage of materials, analogous to that seen in the Weaver Sand-pits, south of the Ribden Mine, about one and a quarter miles away, which had filled up a solution cavity in the limestone and had become consolidated by the percolation of calcareous matter.

THE rocks arising from the metamorphism of the more impure dolomitic sediments are calc-magnesian silicate types in which all carbon dioxide has been expelled. In some of the rocks to be described it is clear that superposed on the normal metamorphism there has been a metamorphism by addition of material from the neighbouring magma.

THE Geological Department of Glasgow University has recently received from Dr. W. R. Smellie and Mr. J. V. Harrison some fossils collected by them which throw further light on the age of the limestones of the Persian arc at the north-western end of Luristan, about 100 miles north-east of Baghdad. The locality, Gilan, is on a tributary of the Diala, about 30 miles south-east of Kasr-i-Shirin, a well-known station on the main road from Baghdad to Teheran. The geology of this part of the Persian frontier has been investigated by J. de Morgan (Miss. Sci. Perse, vol. iii, pt. i, Étud. Géol., 1905, pp. 71–112), who has given a geological map (ibid., pl. xix) of an area about 60 miles south-east of Gilan. De Morgan has identified there a folded series of Cretaceous and Eocene limestones, with lacustrine and gypsiferous Miocene beds. The locality at which the fossils were collected by Messrs. Smellie and Harrison is in line with the strike of the rocks in the area of de Morgan's map.

WITHIN the limits of a brief article such as this must necessarily be, it is impossible to do more than indicate the chief sources of iron-ore supply. The subject is a big one, and of great importance, not only to the British ironmaster, but also to every inhabitant of this country. I am therefore pleased to be able to state that the Federation of Iron and Steel Manufacturers has not only asked the Imperial Mineral Resources Bureau to prepare a summary of the existing information as to the iron-ore supplies of the world, but is also assisting to finance the inquiry. This will mean a more complete survey than is possible to-day.