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.

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.

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.

Increasing attention has been paid in recent years to the reconstruction and interpretation of stream profiles. It might therefore be well to examine a little more closely the way in which the curve of water erosion and the polycyclic valleys are produced. In this paper these problems are considered in the light of some preliminary experimental work recently described in this Magazine (1).

Formerly there were several surface brine springs in the North-East Coalfield; to-day there are none. From the many accounts of their occurrence nothing has been learned of their exact position, and very little of the composition of their waters. The earliest record, made in 1684, described the Butterby spring (Todd, 1684), and then at various times during the next two centuries brine springs at Framwellgate, Lumley, Birtley, Walker, Wallsend, Hebburn, and Jarrow were noted. In particular the Birtley salt spring is often mentioned, and on the 6-in. Ordnance map, Durham No. 13, 1862 edition, it is sited to the south-east of the village. Although no record has been found there must have been either a brine spring or well at Gateshead, for the name of the present-day suburb, Saltwell, is very old, and brine springs are still active in the coal workings of that area.