Crag Formation Research Articles

Lower pleistocene dinoflagellate cyst, foraminiferal and pollen assemblages in four boreholes in the Southern North Sea

AbstractNeogene and Lower Pleistocene stratigraphy in the Southern North Sea has been investigated in four I.G.S. boreholes between East Anglia and the Netherlands. The foraminifera of the Red Crag Formation in Borehole 81/51 are closely similar to Upper Pliocene assemblages in Holland. The overlying succession is clearly punctuated by unconformities in seismic profiles, separating four early Pleistocene formations in the boreholes, and indicating intervals of significant stratigraphic hiatus offshore. The Westkapelle Ground and Smith's Knoll Formations correlate with Thurnian and Antian Stage deposits in East Anglia. Pollen spectra in the Winterton Shoal and Yarmouth Roads Formations are similar to Baventian and Bramertonian assemblages in Britain. The autochthonous marine and allochthonous terrestrial microfauna and flora provide conflicting evidence of early Pleistocene palaeoclimate. The dinoflagellate cysts and foraminifera indicate that each formation was deposited in a warm temperate neritic environment. The pollen record, containing evidence of fluctuation between boreal and mixed coniferous–deciduous regional forest cover, suggests alternation between cool and warm temperate palaeoclimate.

Sedimentary facies in the Red Crag (Lower Pleistocene, East Anglia).

Two distinctive facies are recognised in the Red Crag Formation—a lower megaripple facies and an upper intertidal facies. The structures and grain size distributions of both facies are described, and interpretations of water depth and current directions and velocities are made. The lower facies consists of megaripples of coarse Shelly sand formed largely during periods of high current activity in 15–25 m of water. The upper facies shows an upward transition from infra-littoral tidal conditions, with the formation of medium scale ripples and tidal channels, to tidal sand flat deposits. The nature of the sub-Red Crag surface is briefly described, and the relationship between basal pebble beds and littoral deposits is discussed. The Aldeburgh-Gedgrave Coralline Crag ridge is shown to be an important influence on the local sedimentary environment.

Right- and Left-Händed Spirals in Gastropods

A CORRESPONDENT has raised the question as to whether there is any explanation for the fact that spiral shells of present-day marine gastropods wind in the opposite direction to similar shells found in the Crag formation of East Anglia. The first point is that only certain species of fossil shells wind in this manner, and although it is usual for present-day gastropods to be dextral, that is to say, they wind in the ordinary clock-wise spiral, there are certain genera which always wind in the opposite direction and are sinistral also in species which are usually dextral, there are frequently sinistral varies ties. The well-known fossil shell Fusus contrarius from the Red Crag is so common that it has given rise to the idea that all fossil shells of this kind are sinistral, but there are a large number of fossil gastropods which are normally dextral and, to take but one example, the common ‘Buckie’, Buccinum undatum, closely related to Fusus, sometimes is sinistral although normally dextral. Other common recent gastropods which are known to have sinistral varieties are the edible snail, Helix pomatia, and the common fresh-water snail, LimnÅ"a peregra. A good deal of work has been done, and is still going on, on the breeding of the last-named mollusc in order to find out the reason for these sinistral varieties (Diver, Boycott and others), the conclusion being that the general organisation of the germ cell determines whether the animal is to be dextral or sinistral, the factors for right-handedness or left-handedness being in the chromosomes and inherited in special ways. A sinistral individual may have an entirely sinistral brood or it may have an entirely dextral brood or a mixture, the broods from these varying to a large degree. Besides truly sinistral shells which also have a sinistral animal, there are species with a sinistral shell and dextral animal. It is practically certain, however, that the fossil Fusus must have been wholly sinistral both in shell and animal.

Implements of Sub-Crag Man in Norfolk

Few English deposits have aroused more disputation among geologists than the Crag beds of Norfolk and Suffolk, and on many of the points raised there is as yet no general agreement. This more particularly applies to the sands, gravels, and clays associated with the Norwich Crag, one school considering them part of the Crag formation and therefore Pliocene, and another believing them to be glacial and Pleistocene. Doubt on this matter has had an important bearing on the discovery of Sub-Crag implements in Norfolk, though I believe that the evidence is now incontrovertible. With regard to the basement-bed of the Crag, whether of the Coralline, Red, or Norwich Crag, which appear to have been successive deposits in the order given, the geological evidence as to position and antiquity—though not as to the conditions under which it was deposited—is not disputed. Mr. F. W. Harmer, F.G.S., says:—“In consequence of a combined movement of elevation iu the southern part of this region, and of subsidence towards the north, the whole Crag basin moving as on a pivot, its southern margin was gradually shifted, the sea retiring towards the north.

V.—Memoranda, chiefly on the Drift Deposits in various parts of England and Wales: being Extracts from the Notebooks and other MSS. of the late Sir Joseph Prestwich, M.A., D.C.L., F.R.S., etc.

[For a period of nearly sixty years Sir Joseph Prestwich recorded his geological observations in a series of notebooks. These records, together with the illustrative sections, were afterwards copied, in many instances, into folio volumes dealing respectively with the Eocene and Miocene, the Pliocene and Post-Pliocene formations, and with well-sinkings, springs, etc. The systematic arrangement and indexing of his very copious notes no doubt greatly facilitated the labours of the author. The majority of his notes and sections have been published, but here and there among the notebooks and MSS. there are records of pits and railway-cuttings, as well as some statements of opinion, which appear never to have been printed. A selection of these is now given, together with references to published papers dealing with the same subjects. All additions are put in square brackets.It was the desire of Sir J. Prestwich to have dealt more fully with the phenomena of the Glacial Period, but owing to the many calls upon his time, and to his aim invariably to obtain and to submit fully to his readers all the evidence bearing upon his subjects, he was led to postpone for many years his more elaborate works. Thus his important papers on the Crag formations were issued long after most of his observations had been made. Meanwhile other geologists had entered the field and made known many of the facts which he had previously gathered, a proceeding natural enough and one by no means to be regretted. Thus Sir J. Prestwich remarks in his paper on the Westleton Beds, Part I (Quart. Journ. Geol. Soc., vol. xlvi, 1890, p. 86), that “The Memoirs of the [Geological] Survey, to which I shall have frequent occasion to refer, now supply a mass of valuable details, which greatly facilitate the task and do away with the necessity of much local description.” The notebooks rarely contain any particular expressions of opinion; they simply record facts and only occasionally suggest correlations. The conclusions were for the most part worked out subsequently and embodied in various published papers.Among the MSS. left by Prestwich is the rough draft of the Table of Contents of a paper dated 1892. It includes the following heads:—]

Fossil Cetacea

DURING the recent extensions of the fortifications of Antwerp, which have occupied some years, very fine opportunities have been offered, as is well known to geologists, for studying the Crag formations (Diestien and Scaldisien systems) of Antwerp, of which we have remnants on our own east coast. It is not however, so well known that the Belgian Government during the excavations used every care to preserve the remains of Cetacea and other marine mammalia thus disinterred. The workmen were instructed to give up all such remains for the Government, and were not allowed to sell them. Parts of the Black and Grey Crags proved to be a complete charnel house—so abundant were the remains—and these have been quietly brought together and placed under lock and key for the last eight years. The richness of the fauna disinterred may be judged from the fact that it is stated that eight new genera of Ziphioid Cetaceans are indicated besides sixteen new species belonging to known genera. Many of the forms are represented by far more complete portions of the skull than have hitherto been known from these beds, also portions of the trunk, limbs, and lower jaw in connection with these. Portions of the skull of the fossil Walrus, tusks of which occur in the Suffolk bone-bed and have been described as Trichecodon, have been obtained, as well as remains of seals. All these specimens are under study by the Vicomte du Bus, and are not open to the inspection of even professional palæontologists. They are being carefully and freely engraved, and will soon, it may be hoped, be made known to the world.

XIX.—On some new or little-known shells &c. of the Crag formations

(1870). XIX.—On some new or little-known shells &c. of the Crag formations. Annals and Magazine of Natural History: Vol. 6, No. 33, pp. 213-217.

IV. On the Connection between the Crag Formations and the Recent North Pacific Faunas

All facts from stray sources bearing on the connection between the Newer Tertiaries and existing faunas are worth placing on record, as they may hereafter unexpectedly throw light on important points of inquiry. The existing faunas radiating from the Boreal districts may, indeed, be expected to have much in common, together with species peculiar to each ocean, and to each side of each ocean; and the correspondence extends to species living in the Temperate and even the Sub-tropical districts. Kellia suborbicularis, Lasea rubra, and Saxicava pholadis of the Coralline Crag are now living along the whole coast from Vancouver to the Acapulcan district: and Erato Maugeriw, whose head-quarters are now in the West Indies, appeared in the Coralline, did not disappear in the Red Crag, is now living in the Bay of Panama, and is nearly, if not quite, identical with E. columbella of the Gulf and the Temperate shores of California.

I. Remarks on the Bridlington Crag, with a List of its Fossil Shells

The earlist, and almost the only published, notice of the ‘Bridlington Crag’ is contained in a single page of London's ‘Magazine of Natural History’ for 1835, vol. viii. p. 355, entitled ‘A Short Account of an Interesting Deposit of Fossil Shells at Burlington Quay, by Mr. William Bean.’ Writing from Scarbro’ on March 30th, Mr. Bean states that ten days previously he had made a geological excursion to ‘Burlington Quay,’ when Mr. Walter Wilson, an intelligent lapidary of that place, directed his attention to a deposit of fragile and broken shells, which the late high tides had exposed on the north side of the harbour, and near the pleasure-ground called the Esplanade. On arriving at the spot, he found a heterogeneous mass, only a few yards long, and as many high, composed of sand, clay, marine shells, and pebbles of every description, chalk and flint being most abundant. The colour and appearance of this shelly bed resembled London Clay, but the fossils had the character of those found in the Crag formation. It would be necessary to collect a greater number of species than he had then obtained, and to exercise much caution before the geological position of the bed could be truly determined; but of this much he was certain, that the shells were coeval with, if not of higher antiquity than the Crag. More than half of them could not be referred to any existing species. The writer concluded by mentioning that he had already made a second visit to the place, in company with Dr. Murray, and reaped an abundant harvest.

On the Occurrence of Crag Strata beneath the Boulder-clay in Aberdeenshire

I n the parishes of Slains and Cruden (see Map, p. 348) we have beds apparently of the same age as the English Crag formation. They consist of stratified sand and gravel underneath the boulder-clay, and reposing upon the old rocks of the district. I need not enter into any description of the locality in which these deposits occur, nor of their general character, as these will be found detailed in a paper on the Pleistocene of Aberdeenshire, which the Geological Society did me the honour of printing in the 14th volume of their Journal (see pp. 522–525). I had even at that time some suspicion of their Crag character, from their position below tho boulder-clay, and, further, from the total absence of any glacial striæ or polish upon the pebbles: but I have since then made a close search amongst the comminuted shell-fragments that are everywhere sparingly scattered through the mass; and it is from the character of these, combined with the geological position of the strata, that I infer the age to be probably that of either the Red or the Mammaliferous Crag of England. I have upwards of a score of hinge-fragments which I can safely refer to the Cyprina rustica or Venus rustica of Sowerby’s ‘Mineral Conchology’—a shell which is unknown in the drift-beds, and which, so far as I am aware, has been found only in the Crag; likewise a few fragments of the Fusus contrarius , another Crag form. The prevailing species of Pecten , so far

On the Occurrence of Crag Strata beneath the Boulder-clay in Aberdeenshire

I n the parishes of Slains and Cruden (see Map, p. 348) we have beds apparently of the same age as the English Crag formation. They consist of stratified sand and gravel underneath the boulder-clay, and reposing upon the old rocks of the district. I need not enter into any description of the locality in which these deposits occur, nor of their general character, as these will be found detailed in a paper on the Pleistocene of Aberdeenshire, which the Geological Society did me the honour of printing in the 14th volume of their Journal (see pp. 522–525). I had even at that time some suspicion of their Crag character, from their position below tho boulder-clay, and, further, from the total absence of any glacial striæ or polish upon the pebbles: but I have since then made a close search amongst the comminuted shell-fragments that are everywhere sparingly scattered through the mass; and it is from the character of these, combined with the geological position of the strata, that I infer the age to be probably that of either the Red or the Mammaliferous Crag of England. I have upwards of a score of hinge-fragments which I can safely refer to the Cyprina rustica or Venus rustica of Sowerby’s ‘Mineral Conchology’—a shell which is unknown in the drift-beds, and which, so far as I am aware, has been found only in the Crag; likewise a few fragments of the Fusus contrarius , another Crag form. The prevailing species of Pecten , so far

On the Position in which Shells are found in the Red Crag

Abstract T he unvarying position of the bivalve and univalve shells in the red crag formation of Suffolk and Essex, in many localities, has not, that I am aware of, been ever publicly discussed. The inexhaustible stores of Pectunculi in this formation, as well as the other less numerous bivalves, are deposited in layers of various thickness, from six inches to as many or more feet, each shell having its inside or concavity downwards, and the umbones of the shells having in general an easterly direction.

On Fossil Bones found in the Crag of Suffolk

The author states, that near Ramsholt Creek, Sutton, and in other parts of Suffolk belonging to the Crag formation, large quantities of fossil teeth, hones, and coprolitic substances are found. These remains are rich in phosphate of lime, and are now collected for agricultural purposes. They are found mixed with sand and gravel from two to four feet below the surface, and about 300 tons had been procured from about a rood of ground which had been turned up.

On the Occurrence of the Genus Physeter (or Sperm Whale) in the Red Crag of Felixstow

Some years since, whilst looking over a collection of fossils in the possession of Mr. Brown of Stanway, I was struck by the appearance of a cylindrical nodule from the Red Crag of Felixstow, which seemed to me to exhibit indications of an organic structure unlike that of any fossil body which had previously come under my notice. With the permission of its owner I had a section made of this fossil; but the characters which it presented upon being cut did not enable me to arrive at any determination respecting its real nature. At a subsequent period, I learned from Mr. Brown that the nodule in question had been submitted by Professor Owen to microscopical examination, and identified as the tooth of a Cachalot. In the reports of the British Association for 1842, this tooth is included in the list of British Fossil Mammalia; but Mr. Owen, through mistake, has there assigned it to the “Diluvium of Essex.” I am informed by Mr. Brown, that he procured the specimen from a man at Felixstow, who stated that he picked it up on the beach; and as several of the rarest known Crag fossils have been obtained at this spot under similar circumstances, there is no room to doubt its being a genuine fossil of the Crag formation.

XXVIII. On the crag formation; in answer to Mr. Charlesworth's “reply”

"XXVIII. On the crag formation; in answer to Mr. Charlesworth's “reply”." The London, Edinburgh, and Dublin Philosophical Magazine and Journal of Science, 8(45), pp. 138–139

XL. Some remarks upon the crag formation of Norfolk and Suffolk

XL. <i>Some remarks upon the crag formation of Norfolk and Suffolk</i>