THE purpose of this paper is to present briefly some conclusions drawn from a study of the longitudinal profiles of rivers in the south of England. In the view of the authors, the study of such profiles affords an important though neglected method of attack on the vexed problems of Pleistocene chronology, and it bids fair also to throw light on certain larger geophysical topics, and particularly on the theory of eustatic movements of sea-level.

ONE mile due east of Tantallon Castle, on the East Lothian coast, there stands a conspicuous tower or beacon. Its purpose is to afford an offshore warning to mariners. It has been constructed upon the seaward extremity of a northerly-extending ridge of volcanic ash or agglomerate. In recent years the rocks exposed here have been carefully examined by a well-known Edinburgh geologist, the late Mr. T. Cuthbert Day, and his results are reported in an interesting paper entitled “Volcanic Vents on the Coast, from Tantallon Castle eastwards to Peffer Sands, and at Whitberry Point” (Trans. Edin. Geol. Soc., xii, 1930, p. 213). Mr. Day thought that the ash and agglomerate lying south of the beacon represented the materials belonging to two contiguous but distinct volcanic vents of Lower Carboniferous age. To the twin orifices he applied the designation—“ The Car Double Vent.” In the northerly vent there occur two basaltic intrusions intersecting the pyroclastic rock. One of these, an irregular 4 ft. dyke, trends north-west hard by the easterly side of the beacon. The other, an oval plug covering 500 square feet, or thereby, is situated about 100 yards to the south-east. Both masses were determined petrographically by Mr. Day as “ dark red basalt with conspicuous dark crystals of augite, somewhat decomposed, but appearing under the microscope to approach a limburgitic type ”. It is in reference to these “ limburgitic ” intrusions that I present the following brief note, because, lately, I have discovered that they consist of leucite-basanite, a rock of basic felspathoidal character not previously known to occur in this country.

THE genus Dimorphograptus was founded by Lapworth (1876) for uni-biserial graptolites transitional between Diplograptus and Monograptus, evolution along what is now termed the “ Monograptid trend ” leading to the production of a uniserial proximal portion of the rhabdosome. Akidograptus has been proposed more recently by K. A. Davies for an early stage in the Dimorphograptus series, represented by the species Ak. acuminatus (Nicholson) and Ak. ascensus Davies.

Previous to 1931 the Kakamega area, in the Central Kavirondo Reserve of Western Kenya, was almost unknown from a geological standpoint. Gregory (1, 1921) had made brief references to it, but no detailed geological or petrographical examinations had been made of any part. Following on the discovery there in 1931 of alluvial and reef gold, and subsequently the entry of mining companies into the field, a great deal of geological research has been carried out. During 1934–5 the author, whilst mapping a 35 square miles concession (originally owned by the Eldoret Mining Syndicate—E.M.S.—and subsequently examined by East Africa Concessions, Ltd.), was enabled to make a detailed field examination of a part of the area, and later to examine a series of thin slices of the rocks concerned. The account now given is based on facts accumulated during these investigations.

Banded ferruginous quartzites form a conspicuous feature of many of the outcrops of Dharwar schists in Mysore. Because of their much greater hardness than the associated chloritic and hornblendic schists, these quartzites have withstood the action of weathering agencies better, and form prominent hill ranges in the schist belts. One such important range is the Bababudan hills in the Kadur district, comprising some of the highest peaks in the Mysore State, several of which are over 6,000 feet above sea-level. The Bababudan hills are mainly composed of thick beds of haematite and magnetite quartzites which are separated by bands of chloritic and talcose schists. The high angles of dip and the intensely folded nature of these quartzites are evidences of the great disturbances to which these rocks have been subjected. The complicated tectonics of this area have not yet been satisfactorily elucidated, as geological work on these hills is heavily handicapped by the dense jungles infested with wild animals, and the thick soil cap which obscures the disposition and relationship of the rocks. The ferruginous quartzites overlie an epidiorite flow of spilitic affinities. A few dykes of epidiorite, some of which are tourmaline-bearing, have invaded the quartzites.