words, by the mighty debacle, and what was deposited by the usual currents found in large basins of water, into which huge rivers emptied themselves, that, with our present knowledge, in my opinion, we cannot apportion the effects due to each agent. That the clays, particularly, are composed of transported materials there cannot be a question, for the chalk which forms the substratum of the greater part of western and central Norfolk could not furnish the blue clay so frequently met with upon it: not only this, the boulders, so abundantly found in the clay, inclose organic remains which enable us to determine that their parent rocks are situated fifty, nay hundreds of miles apart from them. Without noticing the fragments of primitive rocks (which are more difficult to identify, in consequence of their not containing organic remains), I may particularize boulders from the old red sandstone, mountain limestone, alum-shale of Whitby, blue lias, cornbrash limestone, Septaria of the Oxford and Kimmeridge clays, &c., all inclosing animal exuviæ that indubitably determine from what strata they were disrupted. As many of these boulders weigh some hundreds of pounds, indeed, some tons*, it is fair to infer that no common current or torrent could have impelled them to their present sites, making every allowance for time; indeed, the magnitude of some of them, the distance they must have travelled, and the want of order in the arrangement of the clay, sand, and gravel, all combine to render it highly probable that the transport of these materials could not have been effected by any other agent than the Noachian Deluge. The light lands covering the outcrop of the chalk abound in bleached fragments of flint, the debris of the abraded chalk; these fragments are in many places (as around Castleacre) so abundant, that it is found necessary to pick them from the land about once in four years, to the amount sometimes of two loads (24 bushels to the load) per acre. The clay of the heavy lands is either yellow or blue: the former contains a large proportion of calcareous matter, and in it large fractured flints predominate, with their angles sharp; the blue clay is in a much greater degree argillaceous, and is also remarkable for the abundance of boulders of the oolitic series of rocks, having all their angles rounded. The gravel beds are principally composed of fragments (in the form of pebbles) of almost every member of the series of rocks, from granite upwards, with every angle effaced, manifestly the result of long exposure to attrition. In some situations, as is exemplified on Necton Common A boulder of breccia in a clay-pit at Fouldon, south of Swaffham, weighs several tons. near Swaffham, the gravel beds contain so large a quantity of decomposing iron pyrites, that the water percolating the gravel is sufficiently charged with iron to cement the sand and stony fragments together, and form a coarse breccia. Under similar circumstances, the water of some springs has a considerable ferruginous impregnation: at Thetford a chalybeate spring occurs, containing also carbonate of soda and free carbonic acid, with a proportion of iron not inferior to that of Tunbridge Wells, although it flows from a very different source; the elaboratory of our chalybeate being situated in the diluvial beds, and the decomposition of iron pyrites from the disrupted chalk strata affording the ferruginous ingredient. Fragments of calcareous tufa are occasionally met with in these beds. Being desirous of not extending this paper beyond the limits of a periodical, I forbear noticing the œconomical and agricultural purposes to which these beds are applied; and for the same reason I shall refer your readers to Mr. Samuel Woodward's Geology of Norfolk* for a list of the antediluvian organic remains, which are, for the most part, inclosed in boulders. The only mammalian remains I have seen are, part of a tusk of Elephas primigenius found at Hunstanton, teeth and vertebræ of Elephas Indicus from beneath the brick-earth at Narford, and part of a tooth of the Mastodon latidens? found in a gravel-pit at Swaffham. It is worthy of notice, that the parent strata from which the boulders must have been originally detached are all situated to the north and the west of our county. Alluvium. -The first deposit I shall notice under this head has received the name of " Brick-earth of the Nar," from my having (till very recently) found it only in the valley through which that river takes its course. In this valley I have traced it west and east from Watlington through East Winch and West Bilney to Narford, a distance of nine miles. It occupies low grou, d, except at its inland extremity, where it rises to about eighty feet above the level of the Nar. Mr. Arthur Young in his "Agricultural Survey of Norfolk," speaking of this deposit, under the article "Manure Oyster Shells," says, "In East Winch and West Bilney, and scattered for ten miles to Wallington (Watlington ?), there is a remarkable bed of oyster-shells in sea mud: the farmers use them at the rate of ten loads an acre for turnips, which are a very good dressing; they are of particular efficacy on land * An Outline of the Geology of Norfolk, page 39, "Clay of Western Norfolk." worn out by corn. They are found within two feet of the surface, and as deep as they have dug, water having stopped them at sixteen or eighteen feet deep. They fall into powder on being stirred." The clay inclosing the shells is of a slate blue colour, and upon drying falls into lamina; it contains numerous spangles of mica, and in the lower part of the bed at Winch and Bilney there is a considerable admixture of sand. It has a very muddy smell when first opened, and the water which rises from it is too offensive to be used for culinary purposes. No boulders have been found in it. At At West Bilney it is generally covered by two or more feet of earth, consisting of vegetable soil, and yellow sandy loam, containing small pebbles and angular fragments of flint. The yellow loam burns into a red brick; a portion lying between the loam and the blue clay, and probably a mixture of the two, produces a mottled brick; and the blue clay, usually denominated the brick-earth, becomes a fine white brick. another part of the brick-yard bleached shells, chiefly Turritella Terebra and Mactra subtruncata, are found immediately beneath the vegetable soil in white sand: the same shells are also scattered through the brick-earth, with Ostrea edulis, Rostellaria Pes Pelecani, &c. At this locality a well was sunk to the depth of forty feet, and Ostree and Rostellariæ were still brought up; but the oysters were most abundant at the depth of three or four feet from the surface. Two fragments of the grinding teeth of the Or, and small portions of bone, were also found in the blue clay, at the depth of five feet. At East Walton, Ostrea, Turbo littoreus, and fragments of a Pecten are turned up by the plough; in a pit they may also be seen imbedded in a light-coloured alluvial clay, rising abruptly from the valley of the Nar to the height of eighty feet above the level of the river: the shells are much more broken than those found in the blue clay, situated at a lower level; indeed, in the latter situation but few are at all injured. At Walton Stocks the same shells were also found. At Narford, near the Hall, in the same fetid blue clay as at Bilney, Ostrea, accompanied by Rostellaria, were discovered beneath a considerable bed of sand and loam; the clay was sunk through at the depth of twenty-seven feet, and in its lowest portion teeth and vertebræ of the Asiatic Elephant were found this is the most inland extremity of this deposit at present detected. The shells of the same deposit have also been found at a brick-yard in East Winch, covered by seven feet of sand and loam: beneath these lie a light-coloured argillaceous earth, six feet in thickness, containing a few shells, which reposes upon the blue clay, in which the Ostrea, Ros tellariæ, &c. are very abundant; the blue clay has here been opened to the depth of ten feet. Very recently have been discovered at this spot, in the loam, fragments of a tooth and bones of an elephant, and a broken tooth of a rhinoceros. In the middle of the village of East Winch, by the side of the road leading to Lynn, Ostreæ and Rostellariæ were discovered on sinking a well; and on Mr. Forster's farm, in the same parish, similar shells were found. At Tottenhill brick-yard, a short distance from the road leading from Lynn to Downham, and at Watlington, the same bed of blue clay is met with, inclosing similar shells to those at West Bilney. The same kind of blue clay was opened last summer about half a mile to the south of Middleton Tower, in a valley running parallel to that of the Nar, and separated from it by the high ground on which the village of Middleton stands; a small stream takes its course through this valley, emptying itself, as the Nar does, into the Ouse at Lynn. Ostrea edulis and Turbo littoreus were found six feet below the surface. In some localities, with the Ostrea have been found Cardia, Mactræ, and other shells, of which the following is a list. The greater number of the oysters are large, thick, and antiquated; they and the Rostellaria are very abundant; Natica glaucina is next in abundance; Pecten and Cerithium are scarce. The shells have not suffered by attrition, but few are broken, and none of them are mineralized. Name. Vermilia triquetra Cardium echinatum edule....... Corbula Nucleus Mactra subtruncata.. solida Ostrea edulis Pecten varius ... { Organic Remains. Brown's Illust., pl. 2. f. 1,5. Wood's Conch., pl. 55. f. 4. Penn. Brit. Zool., pl. 55. f. 2. Tellina,young specimens, species undetermined. Cerithium reticulatum Geol. Norf., t. 1. f. 2. Buccinuni reticulatum Rostellaria Pes Brown's Illust., pl. 43. Elephas Indicus, teeth and vertebræ of. Rhinoceros, fragments of a molar tooth of the lower jaw*. * Dr. Buckland's Reliquiae Diluvianæ, pl. 7. fig. 6. We have here shown, that within the valley of the Nar there occurs an extensive deposit of mud, containing marine shells, the living congeners of which inhabit the adjoining sea. The accompanying map (vol. vii. Plate I.) of the ground occupied by this deposit is a portion copied from the Ordnance map, and exhibits the high grounds bounding the valleys. I have affixed the various localities where the shells have been found, to render my account more intelligible, and to show the extent and course of the deposit. The shells have at present been found on the north side of the valley only, except at Tottenhill and Watlington; they have not been met with on the south side (the present course of the Nar) beyond Wormegay, but occupy the low ground to the north and east of the elevated patch of carstone on which Bilney Lodge stands, and are again found in the valley of the Nar at Narford. The general level of that portion of the brick-earth in which the oyster-shells are most congregated is not much above low-water mark at Lynn; at the Bilney brick-yard they are about seventeen feet above it. Their elevation to the extreme height (about 100 feet) at which they are found at East Walton was probably effected by spring tides in conjunction with storms casting them upon the shore of the creek (presuming this valley to have been once a creek of a sea): the fractured state of the shells and the high angle of their elevation at this locality will, I conceive, justify such an inference; indeed, the equinoctial gales, which here blow with great violence from the west, and consequently towards Walton, would impel waves with corresponding force up this very acclivity. We are therefore led to infer that this valley was, at a remote period, occupied by the waters of the ocean: upon examining the accompanying map, and observing the relative situations of it and the estuary called the Wash, it will be seen that the embouchure of the former is in the direction of the latter; and when we bear in mind that there is a process of filling up constantly in progress in all estuaries, and that our estuary, therefore, must once have extended much higher into Marshland, we cannot doubt that the valley of the Nar at a former period opened directly into the estuary, and that the ocean's waves flowed freely into the valley, forming an extensive creek, bounded by the high grounds of North Runcton, Middleton, and East Winch on the north; those of Walton, Westacre, and Narford on the east; and of Marham, Shouldham, and Tottenhill on the south. I think it not at all improbable that similar deposits of Imud and shells to those of the Nar and Middleton Tower may hereafter be discovered in the valleys of South Wooton Third Series. Vol. 8. No. 43. Jan. 1836. F |