Eocene Series Research Articles

On the Correlations of the “Curiosity-Shop Bed” in Canterbury, New Zealand

The River Rakaia, after leaving the mountains, flows in a south-east direction across the Canterbury Plains. In cutting its way down through the shingles and silts of these plains, it has come across and exposed on its left bank a small patch of calcareous and arenaceous rocks, which are so full of fossils as to have given the name “Curiosity-Shop” to the locality. It is situated between five and six miles below the bridge over the Rakaia Gorge. I visited the Curiosity-Shop in February 1873, and made the accompanying section (fig. 1). All the exposed beds dip 20° E.S.E., and they appeared to me to be]ong to a single series. Mr. A. McKay, of the Geological Survey, has given a detailed description of these beds, which I have embodied in the following Table :— 1. River-gravels. Pareora Series. 2. Loose grey quartz sands, 15 feet thick, with a bed of badly preserved shells. Upper Eocene Series. 3. Soft calcareous sandstone, 10 or 12 feet thick; in the upper part highly charged with glauconite; passing downwards into irregular beds of tufaceous clay. Cretaceo- Tertiary Series. 4. Calcareous sandstone without glaueonite grains. . Loose grey or yellowish-brown sands; 35 feet thick. Nos. 2 and 5 are much obscured by shingle-slips from the high river-bank. The upper part of No. 3 is the principal horizon for fossils, although they are also found in No. 4. & list of

IV.—On the Relative Ages of the American and the English Cretaceous and Eocene Series

I have been desired by the Council of the British Association to contribute some account of the later Fossil Floras of Europe and America, with a view to determining, more precisely if possible, their relative ages.

The Origin of Coral Reefs 1

II. THE most detailed investigation of coral-reefs which has yet appeared has just been published by Prof. A. Agassiz.2 This able naturalist is engaged in prosecuting a series of researches into the biological phenomena of the seas on the eastern side of the United States, under the auspices of the United States Coast Survey, and in the course of these explorations he has had occasion to devote himself to the detailed study of the coral-reefs of the Florida seas. For purposes of comparison he has likewise visited the reefs among the West Indian Islands, as well as those on the coast of Central America. His observations are thus the most exhaustive and methodical which have yet been published, and the deliberate conclusions to which he has come deserve the most attentive consideration. He traces the history of a coral-reef from its latest stages as dry land to its earliest beginnings, and even beyond these to the gradual evolution of the conditions requisite for the first starting of the reef. His familiarity with the nature of the bottom all over the area in question, and with the life so abundant in the tropical waters, gives him a peculiar advantage in this inquiry. The upheaval of recent coral-formations to considerable heights above the sea in various parts of the region enabled him to examine the inner structure and foundations of the reefs, and to obtain therefrom altogether new data for the solution of the problem. Following him in his induction we are led back to a comparatively recent geological period, when the site of the peninsula of Florida was gradually upraised into a long swell or ridge, having its axis in a general north and south direction, sinking gently towards the south, but prolonged under the sea as a submarine ridge. The date of this elevation is approximately fixed by the fact that the Vicksburg limestone was upraised by it, and this limestone is assigned to the Upper Eocene series. As a consequence of the elevation, a portion of the sea-bottom was brought well up into the waters of the Gulf Stream, which were probably shifted a little eastward.

The Origin of Coral-Reefs

II. THE most detailed investigation of coral-reefs which has yet appeared has just been published by Prof. A. Agassiz.2 This able naturalist is engaged in prosecuting a series of researches into the biological phenomena of the seas on the eastern side of the United States, under the auspices of the United States Coast Survey, and in the course of these explorations he has had occasion to devote himself to the detailed study of the coral-reefs of the Florida seas. For purposes of comparison he has likewise visited the reefs among the West Indian Islands, as well as those on the coast of Central America. His observations are thus the most exhaustive and methodical which have yet been published, and the deliberate conclusions to which he has come deserve the most attentive consideration. He traces the history of a coral-reef from its latest stages as dry land to its earliest beginnings, and even beyond these to the gradual evolution of the conditions requisite for the first starting of the reef. His familiarity with the nature of the bottom all over the area in question, and with the life so abundant in the tropical waters, gives him a peculiar advantage in this inquiry. The upheaval of recent coral-formations to considerable heights above the sea in various parts of the region enabled him to examine the inner structure and foundations of the reefs, and to obtain therefrom altogether new data for the solution of the problem. Following him in his induction we are led back to a comparatively recent geological period, when the site of the peninsula of Florida was gradually upraised into a long swell or ridge, having its axis in a general north and south direction, sinking gently towards the south, but prolonged under the sea as a submarine ridge. The date of this elevation is approximately fixed by the fact that the Vicksburg limestone was upraised by it, and this limestone is assigned to the Upper Eocene series. As a consequence of the elevation, a portion of the sea-bottom was brought well up into the waters of the Gulf Stream, which were probably shifted a little eastward.

V.—Notes on Some Sarsden Stones

I. Concretionary with Calcareous Cement.—Last autumn the Rev. John Adams, of Stockcross, kindly took me to see the interesting specimen of Sarsden Stone in situ at Langley Park, north of Newbury, Berks, which he described in the “Transact. Newbury District Field Club,” vol. i. 1871, p. 107, and in the Geol. Mag. Vol. X. p. 200; and which has also been described by Mr. W. Whitaker in the “Memoirs Geol. Survey,” vol. iv. p. 193. This concretionary Sarsden Stone, belonging to the “Woolwich and Reading” series, consists of quartz grains with a Calcareous cement. This is an unusual circumstance for “Sarsden Stone”; and points to the former presence of Shells, perhaps, or of calciferous waters, in that portion of the Lower Eocene series.

On the Presence of the London Clay in Norfolk, as proved by a Well-boring at Yarmouth

T he northward extension of the London Clay has hitherto been considered to have its limits in the southern part of Suffolk. Its lower beds outcrop near Ipswich; at Harwich it is only 23 feet thick; and, as from thence to Bawdsey near Orford, the rise is to the northward, the impression is given that the Eocene series ends under the Coralline Crag somewhere about Orford or Aldborough, and that further north the Pleiocene series reposes directly on the Chalk; such being in fact their superposition throughout North Suffolk and Norfolk wherever the base of that series is visible. An exception, however, to this order has been proved by a well-boring at Great Yarmouth, which was brought to my notice by the Rev. John Gunn, F.G.S., of Irstead. It appears that in the year 1840, the firm of Sir E. Lacon and Co., being desirous of obtaining a larger supply of water, had a shaft dug to the depth of 22 feet, and then a boring carried down to the depth of 597 feet, by Messrs. Clark of Tottenham. Unfortunately this spirited undertaking was not successful so far as the water-supply was concerned; but geologists are nevertheless indebted to Messrs. Lacon and Co. for having preserved a full record of the boring, and specimens of the strata penetrated, which have brought to light some geological facts of interest. On either side of Yarmouth the cliffs consist of Boulder-Clay, with underlying sand- and gravel-beds, ranging for miles in a comparatively horizontal position

On the Structure of the Strata between the London Clay and the Chalk in the London and Hampshire Tertiary Systems

The preceding descriptions I believe embrace, with two or three exceptions, all the principal sections exhibiting the superposition of the basement bed of the London clay. Although, considering the extent of the line of outcrop, they are not very numerous, the intervals between them are sufficiently short to trace this deposit from place to place with considerable certainty. The details of each may vary in a few points, but they all present a general resemblance. This may not however be considered sufficient for our object—such thin and ordinary beds might be subordinate to some other portion of the Eocene series, and not peculiar to this part of them, and therefore some other proofs of their position may be thought necessary. In the first place, all the sections in the tertiary district show, by evidence of the clearest kind, that the London clay forms a nearly homogeneous mass, several hundred feet thick, of tough clay of a predominating brown colour—that throughout its whole body it nowhere presents any subordinate beds of a mineral character essentially different from that of its ordinary argillaceous type—and that its organic remains are very irregularly dispersed, abounding.in some parts and being entirely wanting in others. This clay occupies an area which is very well defined. Now wherever, without a single exception that I am aware of, the lower beds of this clay outcrop, there is found underlying them a basement bed of a conglomerate character and with or without organic remains—and these, if present, invariably belong

On the relative Age and Position of the so-called Nummulite Limestone of Alabama

In a former paper published in the Quarterly Journal of the Geological Society of London (vol. ii. p. 405, May 1846), I stated that the limestone containing abundantly the Nummulites Mantelli , Morton, which occurs near Suggesville, Clarksville, and other places between the rivers Alabama and Tombecbee, in the State of Alabama, was a member of the Eocene tertiary group, and that so far from constituting any part of the cretaceous formation, as had formerly been imagined, it holds in reality a place high up in the Eocene series of the South. In the same memoir I gave a section extending from Claiborne through Suggesville and Macon to the west of Clarksville, Alabama, in which the position of the so-called nummulitic limestone was explained. It was stated to be newer than all the beds of the well-known Claiborne Bluff, and I mentioned that “the bones of the gigantic cetacean called Zeuglodon by Owen were everywhere found in Clarke County, in a limestone below the level of the nummulitic rock and above the beds which contain the greater number of perfectly preserved eocene shells, such as Cardita planicosta and others.”

On the probable Age of the London Clay, and its Relations to the Hampshire and Paris Tertiary Systems

It is not intended on the present occasion to enter generally upon the subject* of the London clay, nor yet to describe its structure and fauna further than may he necessary to prove the argument of this paper, which is, that tne London clay of Highgate, Sheppey, and other places in the neighbourhood of London, apparently is not, as it has hitherto been considered, synchronous with the Calcaire grossier of Paris, nor yet with the clays of Barton, and the clays and sands of Bracklesham; but that it is of older date than these, and consequently occupies a lower position in the Eocene series. Old terms are altered with difficulty; they have the sanction of usage and weight of successive authorities, and are in geology occasionally apt, by their theoretical signification, to stand in lieu of proof. In the case before us, considering up to a late period the contemporaneity of the marine strata of London, Bracklesham, Barton, and Paris well established, I thought it scarcely necessary to investigate the data on which their identification rested; or rather, proceeding under the full impression of its correctness, I yielded to it facts, and endeavoured to conform to it phænomena, which, had I allowed them their due influence, would have earlier led to independent inferences. The differences known to exist in the fauna of these groups had been attributed solely to changes of condition and distance—causes, which as they produce effects whose limits are not easily assignable, sometimes prevent inquiry by offereing

On the main points of Structure and the probable Age of the Bagshot Sands, and on their presumed equivalents in Hampshire and France

In continuation of the paper I had the honour of reading before the Society on the 3rd of February last, I purpose now to examine another division of the Eocene series, frequently incumbent upon the London clay in the neighbourhood of London, and commonly termed the “ Bagshot Sands .” Forming usually barren sandy districts, and rising, over great part of their area, into ranges of heath-covered hills, the Bagshot sands have attracted but little attention, having, although so near London, remained comparatively unexplored since Mr. Warburton described them in 1821*. Without any permanent natural sections, and with few artificial ones beyond an occasional sand or clay-pit, and the curious grave-shaped excavations often scattered over the surface of the gravelly heaths on some the hills, where they are formed in the process of digging out of the sands the occasional masses of conretionary sandstone, the almost only opportunities for studying the structue of the Bagshot sands are afforded by fresh roadside sections and railway cuttings. The fossils are as rare as the sections. The three genera† (for the species were not distinguishable) of testacea found by Mr. Warburton at Chobham; and the subsequent notice by Dr. Buckland in 1838 of the remains of fishes (including the determination of three new genera) at Goldsworthy, near Woking, comprise I believe all‡ at present known of the palæontology of the Bagshot sands§. Notwithstanding however the scantiness of their recent flora and the poverty of their ancient fauna, the Bagshot sands present many features of much