The area containing the quarries discussed in this paper extends inland from the City of Aberdeen for a distance of about twenty miles and is bounded on the north and south by the rivers Don and Dee. This is the area of the Newer Granites of Aberdeenshire, which C. B. Bisset has described in “A Contribution to the Study of Some Granites near Aberdeen” and has divided the acid igneous rocks into:—

1. The Skene Complex: consisting of diorite, adamellite, grey granites, transition types and minor intrusions.

2. Later Group: consisting of coarse red granites.

A series of charnockitic rocks and associated cordierite-bearing rocks from Western Australia has been described and compared with charnockitic rocks from other localities. This charnockitic suite is considered to be a series of basic intrusions into an older series of paraschists. It has, in places, been considerably contaminated by assimilation of the aluminous metasediments and in such cases is now represented by cordierite-bearing rocks. The basic charnockitic rocks and their contaminated equivalents have been subsequently invaded, under deep-seated conditions by granitic magma or emanations, and now appear as recrystallized remnants of the original masses. They have suffered extensive granitization which has yielded the acid charnockites (hypersthene-alkali felspar gneisses) in which the hypersthene is considered to have been derived from the older hypersthene-bearing basic charnockites. In view of the similarity to the Indian and Antarctic charnockites it appears possible that the charnockitic rocks of these areas are of similar origin, and that charnockite (hypersthene granite) rather than being the result of crystallization from a magma, is due to the granitization of older hypersthene-bearing rocks. If charnockite is of magmatic origin then it is most probable that this magma was of palingenetic origin and that the hypersthene is a relict from the earlier rocks and not the product of crystallization of the charnockite magma. Dunn (1942, p. 23) considers that the evidence afforded by Indian rocks is not opposed to the view that the hypersthene gneisses (charnockites) are the product of partial or complete palingenesis of very deep-seated rocks which had lost their water content.

Recent work, both published and unpublished, has considerably increased our knowledge of the goniatite succession in the Namurian of western Europe and the various zones and subzones can now be defined more precisely than hitherto. The major divisions of the Namurian of most value are the former “genus zones” each now raised to the status of an age. Names for these divisions were instituted by Bisat (1928), and were redefined by Hudson and Cotton (1943). The various zones and subzones into which the stages are divided are shown on page 2. The zones differ little from those of previous authors: an attempt has been made to give them equal value and, where possible, the zonal indices in any one stage are of the same genus, thus helping to avoid the confusion caused by the choice as zonal indices of forms of different faunal phase. Neither zonal or subzonal indices are constant in their range in their respective divisions—many of them are confined to a faunal band within the subzone, a few extend into a neighbouring division. The following brief notes are based mainly on the faunal succession of the north of England. The published details of the goniatite faunas in Belgium, Holland, Westphalia, and to a certain extent in Silesia show that the succession there is the same. Comparable forms occur elsewhere as in the Pyrenees, North Africa, Novaya Zemlya, Donetz Basin, Indo-China, Siberia, and U.S.A. The boundaries of the Namurian are those decided on at the Heerlen Congress on Carboniferous Stratigraphy (Jongmans and Gothan, 1937).

The North Sea Basin is enclosed on its western and eastern sides by two axes of elevation, viz. the Pennines (a5 of Text-fig. 7) and the axis of Erkelenz (a3). The fault-zone of the Limburg coal district broadens towards the north-west into the graben of the central Netherlands. In the opposite direction it is connected with the Rhine-graben. The southern border of the North Sea Basin is formed by the Brabant Massif. It dates from at least pre-Carboniferous times, but its influence as a geanticlinal ridge of elevation was manifest in many Mesozoic and Cenozoic epochs. In a voluminous memoir Stevens (6) pointed out that the present morphology of Belgium—e.g. the pattern of the rivers—still reveals the influence of this important element.

While examining some vermiculite deposits at Dangin in 1940, on behalf of Messrs. Brisbane Wunderlich Co., Ltd., some rather friable gneissic to schistose rocks associated with one of the vermiculite occurrences were seen to contain an appreciable amount of a pale bluish mineral which from its optical properties was determined as sapphirine. As this was the first record of sapphirine from Western Australia, the mineral was separated and later chemically analysed at the Government Chemical Laboratory. Descriptions of the occurrence, characteristics, and genesis of this sapphirine and the associated rocks are set out in this paper.

As the result of examining a considerable number of specimens belonging to the species Monograptus fimbriatus, M. raitzhainiensis, and M. triangulatus from certain strata of Llandovery age at a locality in North Cardiganshire, the writer is led to the conclusion that the forms comprised within these species constitute a continuously graded morphological series; and that the stratigraphical occurrence of these forms shows that this series is, further, an evolutionary lineage.

From under the thick blanket of sediments of pre-Karroo age (i.e. Carboniferous or older) which so largely preponderate in the South African stratigraphical column, there protrude immense masses of crystalline rock. In Southern Rhodesia these last consist of granite interrupted at times by still older metamorphic schists, but in places round the borders of the colony, and over the frontier in Portuguese East Africa, they are replaced by gneisses. Recent work has indicated that some of the gneiss is younger than the schists, in spite of the less altered condition of the latter. It is currently accepted, following Maufe, that the gneisses of the northern part of Mashonaland and the southern part of Northern Rhodesia are the metamorphosed representatives of the Lomagundi beds, equivalent to the Transvaal System of the south. The chief difficulty in the way of accepting this view was the presence of less altered limestones and other pre-Karroo sediments resting on the upturned edges of the gneisses and crystalline limestones along some of the Zambezi tributaries. These strata might well be taken to represent the Transvaal System, but the recognition of the widespread distribution of the still younger Waterberg System (= Kundelungu, of the Congo) removes the difficulty introduced by the presence in the area of sediments with a considerable resemblance to the Transvaal beds.

The Magnesian Limestone of England forms a comparatively narrow outcrop stretching southwards for about 150 miles from South Shields to Nottingham. At either end the formation is fairly well known from the many quarries and sections opened up in the industrial areas of East Durham on the one hand and South Yorkshire and Nottinghamshire on the other. Away from these regions, however, our knowledge is scanty, and particularly so in the North Riding of Yorkshire, in the tract of country between the rivers Tees and Swale. Information is lacking mainly because the district is so thickly covered with Glacial and Recent deposits that, except at the extreme ends of this Tees-Swale stretch, rock is nowhere exposed. All the way from the Darlington country down to Catterick and beyond, for sheer lack of evidence the Trias—Magnesian Limestone boundary was assumed to be of normal, unfaulted character, but all was so uncertain that any borings in the area were likely to prove invaluable. How invaluable will be gathered from the following account of two recent bores, which throws an entirely new light, not only on the geological structure but also on the stratigraphy of this obscure region.

Some years ago (Phillips, 1937) I published the results of a preliminary survey of the fabric of some Moine schists by the methods which have been evolved in that branch of the study of rocks now generally known as structural petrology. This survey showed that the quartz, muscovite, and biotite in all the specimens of Moine schist examined have the girdle-arrangement characteristic of a B-tectonic; that the b−axes of these girdles, over a large area of outcrop, plunge in a south-easterly direction; and that the direction of the b−axis of a given specimen is frequently marked by a visible lineation on the foliation-surface of the schist. Study of the fabric of Moine schists visibly affected by the dislocation-phase of the post-Cambrian movements was shown to afford support for the view, already advanced by others on the basis of petrographic study, that the ultimate effect of these movements on the Moine schists is to break down the previously existing fabric; there is a dislocation-metamorphism “undoubtedly superposed upon the general Moine metamorphism” (Read, 1934, p. 307).

When describing river terraces in his recently published account of the “Ice Age in West China” Richardson has assumed without question that in a period characterized by climatic oscillation wetter (and generally also colder) episodes result in aggradation and that degradation follows diminished precipitation.

Since the publication of the papers by Messrs. Gardiner and Reynolds on the Tourmakeady and Glensaul districts in the west of Ireland, with palaeontological appendices by the present author, Raymond (1925, p. 167) has compared the faunas with those of Newfoundland and pointed out some striking resemblances. Other Lower Ordovician faunas have since then been described from various foreign regions, and in the light of this increased knowledge the specimens in the collections from Ireland have been re-examined; this has resulted in revised generic identifications, though confirming the reference of the beds to the Lower Ordovician as the author originally maintained (1910, p. 271). The trilobites, several of which are now put in other genera, are mostly allied to or comparable with species of the Canadian and Ozarkian of North America, Newfoundland, and Greenland which Poulsen (1937, p. 72) correlates with the Arenig and Tremadoc, and they also show resemblances to some of those of the Ceratopyge fauna (Brögger, 1896) of Europe and Western North America (Raymond, 1922) as well as with those of Newfoundland. The brachiopods, the determination of which had been found a matter of much difficulty owing to their poor preservation, possess affinities with many of the American Upper Ozarkian and Canadian species recently named by Ulrich and Cooper (1938), especially with those from Canada, rather than with any of the European forms with which they were previously compared or identified. The admixture of Upper Cambrian fossils with those of the Ceratopyge zone, especially in Nevada and the Mount Robson district, was noted by Raymond (1922, p. 20); and similar interrelations of the two faunas are also traceable in the present case. From the general aspect of the faunas from the Irish localities, Ulrich (1930, p. 19) was inclined to put the beds “about the middle or upper Chazyan”; Grabau (1935, p. 101), relying on the lists of brachiopods and trilobites in the present author’s original papers, would refer them to the Middle rather than the Lower Ordovician, but this view can no longer be held.

With the removal of certain genera the Illaenidae has become a very homogeneous family. Attempts have been made to group genera into subfamilies, the most important of which was that made by Salter in 1867, but these efforts have not met with general approval. Thus Warburg (1925, pp. 97–100) has given a recent summary of the Illaenid classification and discussed the previous literature, and this author endorses the opinion expressed by Raymond in 1916, “that it is still too early to make any natural classification.” Whittard (1938, p. 89) follows Holm and Warburg and meantime would only admit Illaenus and Bumastus as valid genera and suggests that Salter’s genus Ectillaenus might be retained for species of Illaenids in which visual organs were either absent or vestigial.

With regard to the relation between climatic oscillation and terrace formation, some ideas that I have collected in the course of studying accelerated (man-made) erosion, may be useful in a geo-morphological setting. Huntington’s principle and the idea I used in my paper “The Ice Age in West China” are not necessarily opposed, if one limits the application of Huntington’s principle to semi-arid regions which are just on the margin of being able to support a vegetative cover. In such regions a further decrease in precipitation, leading to serious reduction in the protection afforded by vegetation, would accelerate erosion on hillsides and steep valley floors, and this in turn would lead to deposition of spoil on more gently sloping valley floors lower down. A further oscillation of the climate, in the direction of increasing rainfall, would restore the vegetative cover, reduce erosion, reduce the load in the rivers, and allow downcutting to continue. But a still further increase in precipitation might be expected to increase erosion of the type associated with landslips and flooded streams and rivers; once more increased load will be swept down from the steeper hills and stream-beds to the lower and gentler slopes of the rivers, where it will be deposited. In other words, one may say that there is a level of precipitation, probably a moderately low one, at which (apart from human interference) there is a close vegetative cover and geological erosion is at a minimum; any appreciable departure from this level of precipitation in either direction will cause increased geological erosion in the upper courses of streams, and hence increased deposition in their lower courses.

In the course of discussions on Echinoderms between the senior and junior authors, the family Cromyocrinidae came under scrutiny and in view of a vital link of evidence in the form of a Pennsylvanian (Upper Carboniferous) specimen of Ulocrinus buttsi Miller and Gurley with the arms attached, found by the junior author a few years ago, the following interpretation of the family is suggested.

Haematites of great commercial importance occur in West Cumberland, chiefly in the Carboniferous Limestone. Worked as early as the twelfth century the annual output reached half a million tons by 1861, since when the output has varied between that figure and one million tons. During these years of active exploitation many ore-bodies in the exposed ore field were worked out and active exploration is now concentrated around and to the south of Egremont, where the Carboniferous Limestone plunges beneath the New Red rocks. Among the problems confronting the searchers for new ore-bodies in this concealed ore field there is one of long standing, upon which unanimity has not been reached, namely the origin of the haematites. The question of origin is not one of mere academic interest. Its solution affords an important clue in the search for new ore-bodies. Two theories—magmatic origin and deposition from meteoric waters—are and have been propounded by rival advocates during the last fifty years. J. D. Kendall (1893) attributed the origin of the ores to ascent of magmatic solutions in pre-Permian times. To him we owe the theory of metasomatic replacement of the limestone by haematite, now generally accepted.

In the Central Coalfield of Scotland Carbonicolapseudorobusta Trueman occurs at several horizons in the ovalis zone of the Coal Measures. During a statistical investigation l of this species two of the most important horizons examined were the roof of the Shotts Gas Coal, and the mussel band above the Upper Drumgray Coal (Weir and Leitch, 1936, p. 704). The Upper Drumgray horizon marks the top of the zone and the Shotts Gas Coal lies about 100 feet below. The roof of the latter, about 4 inches thick, is a tough highly carbonaceous shale in which specimens of Carbonicola, while not numerous, are well preserved in solid form. The Upper Drumgray mussel band is composed of about 9 inches of black shale containing crushed shells in great abundance. Over 300 specimens were collected from each horizon, mostly from the tip heaps of collieries. In the case of the Shotts Gas horizon the fossils were obtained from three collieries which lie within an east-west rectangle two miles long by half a mile wide.

Pathological individuals or monstrosities of ammonites (kakomorphs in Buckman’s terminology) have long been known and some have, rightly or wrongly, been given specific names. Indeed, they probably include a genus, namely Nipponites, Yabe, 1904, based on a unique specimen, the incredible tangle of which may represent only an extreme monstrosity of one of those Nostoceratids (Didymoceras, Emperoceras, etc.) which normally began life with a hamitid or ptychoceratid shell, then changed to a turricone and finished up with a helicoid body-chamber, often combining dextral and sinistral coiling in the same individual. A few authors have taken delight in collecting and describing such “cripples” (Engel, 1894, 1909; Wingrave, 1929); to other palaeontologists, however, they have caused nomenclatorial difficulties. Thus Crick (1901), when recording as Ammonites ramsayanus, Sharpe, a monstrosity in the Bath Museum, had to confess that Sharpe’s type specimen certainly was deformed and he thought the Bath specimen was also a malformation. Yet he added “being unable to refer them to any other species which had hitherto been described from the Chalk, it seemed desirable to retain, at least provisionally, Sharpe’s name”. Crick should have known, of course, that a specific name may be valid or invalid, but that it cannot be provisional. In other papers, however, dealing with deformed ammonites, Crick (1898, 1899, 1918) found the nomenclature less embarrassing.

The majority of the Scottish specimens described in this paper consist of cups only, and have been in my collection for a long time. In earlier days they would probably have been assigned to genera like Poteriocrinites and Pachylocrinus, but in recent years great additions have been made to our knowledge of Carboniferous inadunate crinoids by American workers such as Kirk, Moore, Laudon, Strimple, and others. New genera and species have been created, many of them based on all the characters of complete crowns. Obviously, when dealing with cups alone, it is not always easy to trace exact relationship to such perfect examples of crinoid life. It seems evident, however, that the cups here dealt with differ in certain ways from forms so far described, and an attempt is now made to give them specific standing. Four new species are ascribed to known genera, three, including two new species, to the new genus Scotiacrinus, and one to a new Cromyocrinid genus for which the name Tyrieocrinus is proposed. A revision is also given of the species previously described as Erisocrinus scoticus (Wright, 1942, pp. 275–6) and now referred with reservations to Apographiocrinus Moore & Plummer. I wish here to thank Dr. A. C. Stephen, of the Royal Scottish Museum, for the loan of a specimen belonging to that institution, now named Scotiacrinus yoredalensis, and the authorities of the Museum for permission to describe and figure it.

The only species of Scaphites hitherto identified from the Holaster planus Zone of England is S. geinitzi d’Orbigny, which occurs commonly both in the Chalk Rock and in the normal facies of the zone in many parts of the country.

These papers on a puzzling complex of igneous rocks are of special interest. The question is: Has there been a remarkably thorough-going metasomatism of basalt, or none at all? If the complex is extraordinary the conflicting hypotheses advanced to account for it are hardly less so, for we are invited to credit lavas with hitherto unimagined potentialities and behaviour.