In an article with the foregoing title (Geol. Mag., Vol. LXVII, 1930, page 97) some unfortunate errors of statement, in part quite unaccountable, were printed.

It has been made eminently clear by Suess1 in his great synthesis of the structure and form of the planet that between those mountain systems which come into contact with one another there are very different types of structural connection. Suess' interpretations of various examples, now famous, are so well known that no repetition is here necessary, Moreover, his brilliant work has invested the subject with a surpassing interest which has led many others to give it their attention. Already the structures of the junctions between many of the world's mountain systems are understood. But the connection between two of the great mountain systems of western North America, the Coast Range of British Columbia and the Cascade Range of Washington, has been largely neglected by geologists, or misinterpreted, if not indeed completely misunderstood. Even Suess' interpretation is open to objections: it fails to separate the two ranges, and to correlate the structures of the Cascades in any way with those of the Interior Plateaux or the Rocky Mountain System.

In view of the probability that there is likely to be some little delay in publishing the official Memoir on the Bufumbira volcanic rocks, which is in course of preparation by Mr. A. D. Combe and the writer, with, we hope, collaboration with authorities in England, permission has been given to publish a short summary of the results so far obtained in the investigation of these rocks. Mr. Combe has made a careful geological survey of the ground and has separated on his map forty-nine flows from nearly forty different centres situated at the south-west corner of the Uganda Protectorate. The remainder of this large volcanic field lies in the Belgian Congo to the west and south, and though all of those volcanoes, several of which are still active, have been visited by geologists and specimens of the rocks obtained, no very detailed field-work has been published on them, either by us or any other observers up to the present time; so far as is known to the writer.

The Quaternary System has always presented peculiar difficulties to those geologists who have attempted to work out its chronology, largely owing to the fact that it is not always easy to correlate the details of one locality with those of another. In some cases at least, this appears to be due to lack of knowledge of the detailed sequence of events within a limited district, whether such a sequence is considered from the climatic or from the cultural point of view, or from a combination of both. The main object of the present paper is to enquire into the state of our knowledge concerning the Quaternary and Recent train of events which have taken place within a limited district, so that in the future this area can be compared with others which will have been treated in a similar way.

Of the naturally occurring forms of (Mg, Fe) SiO3, only two are of any great petrological importance. Rhombic pyroxenes of the enstatite-hypersthene series are common in many igneous rocks and in the metamorphic derivatives of these and of sediments. Members of the anthophyllite group of rhombic amphiboles are of much more restricted occurrence, being practically confined to crystalline schists and metasomatic products. The stability relationships of these forms and of the rarer monoclinic clinoenstatite and kupfferite were originally investigated by Allen, Wright, and Clement. Enstatite was obtained by crystallizing a glass below 1100° C., and anthophyllite by very rapid cooling from a melt at about 1600° C. Some uncertainty still exists, but it is clear that at least under normal pressure clinoenstatite is the only stable form.

The petrology of the Mid-Jurassic sands in the south-west of England has been described both by Professor P. G. H. Boswell and Dr. J. G. A. Skerl. Professor Boswell has dealt with the Toarcian-Aalenian sands from various localities between Cheltenham and the Dorset coast; Dr. Skerl with certain Bajocian and Bathonian beds in the North Cotteswolds. The present paper gives some account of the lithology and terrigenous minerals of the oolitic limestones of Dundry, an area approximately midway between the Cheltenham region and the south coast. Dundry Hill is an isolated patch of Oolite some 8 miles west of the Bath Hills, and Dundry village, which stands on its crest, is 5 miles south of Bristol. The geology and palaeontology of the area have received the attention of many geologists from the time of Conybeare and Phillips, but here only the work of S. S. Buckman and E. Wilson need be referred to, since these authors fully review the previous literature. Buckman and Wilson described the rocks in great detail, and their classification of the strata has been utilized here.

Dr. Dixey, in his interesting paper on the “Geology of the Lower Shire-Zambezi Area” in the February number, remarks upon the resemblance shown by his Nachipere Series (first mentioned in the Annual Report for 1926, p. 6) to the series of completely metamorphosed sediments described by me under the name “Turoka Series” in 1913 (Quart. Jour. Geol. Soc., lxix, p. 534).

During an expedition to the Lake District, led by Miss Elles, the contact of the Threlkeld microgranite with the rocks into which it has been intruded was examined. The lower contact of the microgranite with the Skiddaw Slates is now well exposed at the eastern end of the main quarry south of Threlkeld railway station; and also in the light-railway cutting connecting this quarry with the newer quarries to the S.W. This contact is transgressive to the bedding of the slates, and at the first-named exposure the two rocks are dove-tailed into each other. The slate can be seen to be but slightly hardened and so little alteration has been effected that well-preserved graptolites were found within 18 inches of the contact.