This paper gives an account of an investigation of the Carboniferous glacial deposits that crop out along the valley of the Arroyo de las Cabeceras, which is situated in one of the western front ranges of the Precordillera of San Juan, Western Argentina. The field work was carried out by one of us (J. Keidel) and the detailed examination of the fossils collected by the other (H. J. Harrington).

During the past ten years a number of papers dealing with progressive regional metamorphism in the southern portion of New Zealand have been published. In the following pages a brief summary of the assemblages of minerals typical of the various metamorphic zones is given, but the writer's main object is to draw attention to certain mineralogical and structural peculiarities that appear to differ in some degree from what are usually regarded as the normal features of regional metamorphism in such classic areas as the Scottish Highlands and the Caledonian chain of Norway. The possibility that such departures from the normal may in some instances be connected with chemical peculiarities in the parent rock is suggested by such phenomena as the well-known general limitation of chloritoid, staurolite, and low-grade garnets to pelitic rocks of special chemical compositions. Other unusual features, especially when found to recur in widely separated regions, may well be governed by some particular combination of physical rather than chemical conditions.

The grits which occur intercalated among the Harlech Grit Series have very similar lithological characters throughout. In the field the individual grits are very persistent laterally and can be traced over large areas. During the course of work on the man-ganiferous members of this Series one such grit horizon, which has been termed the “Bluestone Grit”, and which occurs about 5–6 ft.

The Bergschrund Hypothesis, when it was enunciated by Willard Johnson (I) at the end of last century, was almost universally welcomed as an explanation of cirque formation. Since that time it has continued to dominate the literature on glacial sculpture. Gilbert (2) and Hobbs (3) in America, Wright (4) in this country, and Penck (5) and de Martonne (6) on the Continent follow his ideas with only very minor modifications. The essentials of this hypothesis were, however, outlined by W. M. Davis (7) contemporaneously with the publication of Johnson's 1899 paper.

There are three principal types, peat, fen clay (otherwise called blue buttery clay), and silt, in the post-glacial deposits of the Fenlands, which lie mainly within the shires of Cambridge and Lincoln, and Norfolk. It has long been known that Foraminifera occur in the silt and clay. The genus Lagena was recorded from the silt by Williamson in 1848, with twelve species from March, and sixteen species from Boston. In 1865, Parker and Jones listed thirty-five species of various genera from four samples of sub-Recent clay and silty clay from near Peterborough, Boston, and Wisbech. In 1870, H. B. Brady described the living brackish water Foraminifera from our coasts, and compared them with those recorded from the sub-Recent Fenland deposits by Parker and Jones. In a footnote (p. 306) he added the record of eight more species, so he presumably had a private communication from these authors, or himself studied further material. In 1881, James Green in two short papers noted the occurrence of abundant Foraminifera in layers of the March roddon, and figured nine species therefrom.

The Glen Tilt Complex, one of the larger masses of the Newer Granites of the Central Highlands, is included in sheet 64 of the Geological Survey of Scotland. The greater part of this complex is a granite which is bounded on the south-west and southeast by an earlier series of intermediate and basic rocks. The granites described in this contribution are restricted to a small area at the south-eastern margin of the large granitic intrusion generally known as the Beinn Dearc granite. The smaller and independent intrusion of the Sron a ‘Chro’ granite and a number of smaller masses of granite associated with the marginal strip of diorites on the north-western side of Glen Tilt have also been examined. These small isolated areas appear to be contemporaneous with the intrusion of the main Beinn Dearc mass and have been intruded between the earlier diorites and the margin of the intrusion, a feature not uncommon in many of the other Scottish Newer Granites. A small independent mass of muscovite-biotite-granite intruded into quartz-mica-diorite occurs on Conlach Mhor. Although these rocks are completely isolated from both the biotite- and muscovite-biotite-granites of the main Beinn Dearc intrusion their essential similarity with the latter leaves no reasonable doubt of their common origin.

As a result of three recent expeditions to East Greenland a remarkable dyke swarm, following closely the general direction of the coast, has been found to run from the neighbourhood of Scoresby Sound to Angmagssalik, a distance of 500 miles. The dykes are dolerites of various kinds and for the most part they are intruded into a thick Tertiary basalt series and the underlying metamorphic compled.

The writer made a journey recently on the Continent to study the various facies of the Lower Devonian in connection with work on a fauna from New Zealand. Although not directly concerned with the lower limit of the Devonian System he gathered certain information regarding faunas near that boundary. This was especially a consequence of an invitation to the international excursion in May, 1937, arranged by the Prussian Geological Survey to discuss the Siluro-Devonian boundary and view a series of trenches at Hüinghausen, Westphalia, which, it was hoped, would expose the passage beds between these systems. The Prussian Geological Survey generously allowed the writer to collect somewhat later from these trenches. Professor Pruvost also invited the writer to examine the collections from Liévin at Lille, and later loaned a series of specimens for more detailed examination. For all these kindnesses the writer expresses his thanks. Mr. S. H. Straw has kindly read through the manuscript and made many valuable suggestions, and the writer had the benefit of discussion with Professor Richter of Frankfurt who also helped with material for comparison. To the authorities of the British Museum, the Museum of the Geological Survey, and the Sedgwick Museum the writer is indebted for the loan of, or access to, figured specimens. He also acknowledges a grant from the Royal Society which enabled him to make a journey on the Continent.

Manganiferous schists carrying cummingtonite or grunerite are now known from several areas of the Lewisian of Scotland. Cummingtonite in paragneisses was first described from the Gairloch area (1)1 and it has since been met with at two localities in the Lewisian inlier of Glenelg—at Druideag Lodge, Loch Duich (2), in association with eulysites, and in the gorge of Glen Beag, 5½ miles south of this points—here associated with rhodonite and pyroxman-gite (3).

AMMONITES VARIANS J. Sowerby2 is a composite species, based on five syntypes, which are preserved in the British Museum (Natural History),3 and have long been accessible to any reviser who wished to select a lectotype from among these syntypes. Nobody, however, has yet done so. In the days of the early revisers, of course, from Mantell and Brongniart (1822) to Sharpe (1853), nomenclatorial restrictions were unknown; and even when Semenow (1899)4 dealt with Sowerby's species, he accepted the customary interpretation of Schloenbachia varians without going back to Sowerby's original description and figures. Semenow took d'Orbigny's5 excellent figure as typical, and his restriction seemed to me convenient to adopt,6 if not actually binding. But on going more fully into the matter I discovered not only that Semenow's selection (if it be selection) is not valid but also that none of the forms which authors nowadays identify with Schloenbachia varians agrees either with Sowerby's description or with any of the syntypes in the British Museum. It is thus highly desirable to discuss this common zonal ammonite species and place its interpretation on a sound footing.

In this country the species which at one time or another have been assigned to the genus Platycrinus amount to a considerable number. From the works of J. S. Miller, J. Phillips, A. Goldfuss, T. and T. Austin, F. McCoy, de Koninck and Le Hon, etc., one might make up a list of well over a score of species, but to identify specimens from the British Carboniferous limestones with the figured or described species is a very difficult matter. This is due chiefly to the poorness of the illustrations of the species concerned or, when the figures are passably good, to the lack of prominence given to the more important characters of the calyx. Two at least of McCoy's species and one of Phillips's are not illustrated at all. There is also some confusion regarding certain species which seem to have been figured more than once under different names. In the process therefore of identifying specimens it soon becomes evident that few of the species have been placed on a satisfactory basis and that as a group the British Platycrinidae is much in need of revision.

The purpose of the present note is to give a synopsis of the most important differences between assemblages of small foraminifera from rocks of Upper Cretaceous, Eogene, and Neogene age respectively, in the Middle Eastern region.

Recent work on the succession and structure of the Skipton Anticline1 has proved strata about 6,000 feet thick. These beds are of Dinantian age ranging from γ to P2 and are in great contrast to the strata of the Askrigg massif, 8 miles to the north, where the Dinantian is of S1 to P2 age and is only 800 feet thick.

Before I went to Malaya in 1903 I had worked for two field seasons in Cornwall as a very junior member of the staff of the Geological Survey, and since my retirement in 1931 the old interests in Cornwall have attracted me, with the result that from 1935 onwards I have been doing field-work each year in the Lizard Peninsula. My original object in going to this part of Cornwall, armed with the 1912 Geological Survey Memoir (The Geology of the Lizard and Meneage, J. S. Flett and J. B. Hill) and the two 1-in. maps dated 1912 and 1934, was humbly to follow the work of my seniors in a part of Cornwall to which I had not previously penetrated, without any idea of criticism; but, although anyone who is conversant with the geology of the Lizard must agree with by far the greater part of the 1912 Memoir, in the course of my very enjoyable trips, during which I had the advantage of discussions with Sir John Flett and Dr. E. M. L. Hendriks, points have cropped up that are new or present problems on which I cannot see eye to eye with the surviving author of the Memoir, who has suggested that I should publish my results before he produces a new edition.

Although British and American forms of this genus all bear points of resemblance to Temnocheilus ventro-concavus, only two small specimens from Eastern Europe, Nautilus dorso-armatus Abich, resemble it in their possession of a flattened concave venter and a whorl section of quasi-quadrilateral shape.

The olivine-rich rocks have acquired a particular significance in petrogenetic discussions as a result of the growth ofthe realization of the difficulties involved in postulating the existence of anhydrous melts of corresponding composition.The belief that such rocks have originated through the local accumulation of olivine crystals, without significant remelting (Bowen, 2, p. 108; 3, pp. 133–174)1 has received added support from the experimental determination ofthe melting relationships of the olivines. The facts “seem susceptible of no other interpretation than that, when such masses become rich in olivine, they do so through the accumulation of crystals of that mineral, which remain as such and do not become a part of the liquid by remelting or re-solution” (4, pp. 394–5).

The name “fassaite” (Werner, 1817) was originally given to the leek- to dark-green pyroxene crystals of the Fassatal, characterized by a distinct habit with the zone [110] strongly developed. Subsequent to the analytical data of Doelter (l) on the Monzoni fassaites the name has come to be applied more generally to alkali-poor aluminous pyroxenes found in metamorphosed lime-Stones and dolomites. Doelter's analyses of the Monzoni fassaites date back as far as 1877 and are chiefly remarkable for their high alumina and ferric oxide contents.

Sule Stack is composed of an orthogneiss traversed by shatter belts and small pegmatite veins composed of microcline and quartz. The chief constituent minerals of the gneiss are oligoclase and orthoclase felspars, hornblende altering towards chlorite, augite, and apatite. In addition some sections show magnetite and a few quartz. Comparisons are made between the gneiss of Sule Stack and that of the neighbouring island of Sule Skerry.