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474 suB-~Re~.n T.A~D-SVRFACESA~ ~ARR~. [Aug. X896,

27. On SUB~ROED LAND-SVRFACES at BARRY, G~AMORGANSHIRE. By A. STRA~, Esq., M.A., F.G.S. ~th NOTES On the FAV~A and Fr.ORA by CLEmEnT REIn, Esq., F.L.S., F.G.S. ; and an APPE~vix on the MicRozoA by Prof. T. R. Jo~s, F.R.S., and F. C~AP~AN, Esq., A.L.S., F.R.~I.S. (Communicated by per- mission of the Director-General of H.M. Geological Survey. Read March 25th, 1896.)

BA~Rr Is~.a~'v lies off the northern coast of the , about 7 miles south-west of Cardiff. Until the year 1884 it was separated from the mainland by ~he tidal estuary of the Cadoxton River on its northern side, and on the east by a tract covered at high water, but in which the solid rock cropped up through the tidal ~ deposits at frequent intervals, the most conspicuous prominences being known as the Coston, Mark, Bendrick, and Black Rocks. In the absence of evidence to the contrary we may assume that the course followed by the river at this time was its original course, for it falls into the general south-westerly direction of the rest of the valley. The numerous outcrops of rock, moreover, in the tidal area east of the island make it unlikely that there was an outlet here of sufficient depth to drain the marshes behind it. This tidal area seems to have been one of three low co/s in the water-parting on the southern side of the Cadoxton Valley. One of these would separate the western par~, or the Litble Island, from the main part~ of were it not for a ridge of blown sand; another occurs east of Hayes Farm, where, as shown by the Ordnance level 19 given on the map facing this page, the alluvial marsh of the Cadoxton River closely approaches the present coast. The third, presumably a trifle lower than either of the others, was submerged during the subsidence of the land, of which proof will be given in the following paper. It was therefore as a direct consequence of this subsidence that Barry was separated from Hayes Farm and became an island, while a slight increase in the extent of the movement would have given us three islands instead of one as the result of the submer- gence of the old water-parting. As to the da~e of the insulation of BarD', it will be seen subse- quently that it had not taken place before Neolithic times ; on the other hand the island is, I believe, referred to as such in the earliest historical records. In 1884 the were commenced. The river was diverted from its ancient course and carried to the sea by an artificial cut east of the gap referred to. Its former valley on the northern side of the island was partly filled up and partly excavated to form a deck, the entrances to which were made in the tidal area east of the island, the sea being excluded by a wall. Subsequently a second dock (shown on the map as 'Barry Docks Extension ') was commenced in this reclaimed area, and it was the excavation made Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

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476 xR. A. 8TRAHAN ON SUBMERGED LAND-BURFACI~IS [Aug. I896,

for this purpose that I had the opportunity of examining in the course of my duties on the Geological Survey in 1895. The history of the invasion of the river-valley by the sea through the gap mentioned clearly reveals itself in the sequence of deposits ; but, morethan this, the river-alluvium presents a series of freshwater beds and land-surfaces, whose position in relation to the present sea-level proves that a great change in the level of the land took place during and after Neolithic: times. On some of my visits to the Dock I had the advantage of the assistance of Mr. F.T. Howard, F.G[8., and of Mr. J. Storrie, to the~ latter of whom I am indebted ibr much information respecting the sections exposed in the earlier dock, and also for the identification of some of the specimens from the present excavation. To my colleague Mr. Clement Reid, however, I am indebted for a thorougk examination of the whole of my specimens, and for the identification of both plants and shells, together with critical remarks thereon.. Prof. Rupert Jones, F.R.S., has kindly furnished me with the list of ostracoda, etc., given in the Appendix. The natural topography of the tract is preserved on the 6-inck Ordnance maps, Glamorgan L. and LI. (published 1885, surveyed in 1878), from which the accompanying map (p. 475) has been prepared. The high-water mark of ordinary tides being shown on these maps. in the usual manner, we are able to see that the whole of the new dock is being excavated in ground that was covered at high tide, : though it pretty closely approaches the eastern shore at a point known as Warren Tump (now levelled). The extreme southern point of the dock lies near what was formerly a Shoal known as Coston Rock. In both these parts the excavation is principally in the solid rock, but elsewhere it generally fails to reach the bottom of the alluvial deposits. These may be enumerated as follows :--- 1. Blown Sand. 1 2. ~brob/cu/ar~z,clay. ~ Recent subaerial and tidal deposits. 3. Sand and gravel. Strong line of erosion. 4. Blue silt, with many sedges. 5. The Upper Peat Bed ; about 4 feet below Ordnance-datum. 6. Blue silty clay, with many sedges. 7. The Second Peat, a thin layer only. 8. Blue silty clay, as no. 6. 9. The Third Peat, many large legs and stools, and roots in place underneath; about 20 feet below Ordnance-datum. 10. Blue silty clay, with reeds, willow-leaves, and freshwater shells. 11. The Fourth Peat, with large trees and roots in place. Land-shella numerous. 12. An old soil with roots and land-shells ; about 35 feet below Ordnance- datum. Rock in place.

By the kindness of Mr. James Bell, En~neer to the Barry Dock Company, I have been furnished with the following levels :-- Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

Vol. 5~.] A~ ~RRI, aT.~OR~S~IS~. 477 Above Below Ordnance- Ord~ance~ datum. . datum. feet. feet. Quay-level, coping round Dock, Basin and Deep Lock ""l 26"50 High-water ordinary spring tides ...... I 19"70 High-water ordinary neap tides ...... 1 11"30 Mean sea-level at Barry ...... 1 1"60 Low-water ordinary neap tides ...... :1 8"3 Low-water ordinary spring tides ...... I 16"4 Bottom of Dock ...... I 20"0 1. The blown sand occurs only on the eastern side of the tidal area, whence it was evidently drifted by the south-west winds. The supply was never great, and is now of course entirely cut off. 2. The Scrobicularia-clay occurs in considerable force towards the north-eastern end of the excavation. It is a stiff, brownish clay, jointing vertically as it dries. It contains an abundance of ~crobicularla plans, with the valves united, and in this and other respec~;s resembies the mud which is now being deposited in the more sheltered part~ of the Bristol Channel In the present case it found no rest on the shoals east of the island, but accumulated in some force from near Warren Tump upwards along theriver-valley, as indicated on the map. The greatest thickness seen in the dock was 9 feet. 3. This sand and shingle forms the base of the Scrobicularia-clay, into which it passes insensibly upward. It ranges from 2 to 8 feet in thickness~ according to local circumstances, and is full everywhere of recent shore-shells, all more or less:rolled. Among these the following species have been identified by Mr. Clement Reid:--Scrob~laria Tlana , Tellina balthica (the thin-shelled estuarine form), Gardium edule, Patella vulgata, I, ittorina littorea, L. rudis, and L. obtusata, Southward tMs sandy and gravelly tidal wash extends in a patchy manner among the rocky shoals towards the present foreshore, where it is still in course of formation. The deposits described above were all in process of being laid down, until the area was taken in hand by the Barry Dock Company in 1884. They rest upon a conspicuously eroded surface of the strata about to be described, with which also they contrast :strongly in their contents and character. The erosion is attributable to the scour of the tide when the sea first gained access to the estuary round the eastern end of the island. The series of deposits upon the description of which we n~w :enter forms a continuous sequence from top to bottom. It may gene- rally be described as a mass of fine clayey silt with abundant remains of sedges in the position of growth throughout, and with four or more bands of peat, only three, of whleh, however, are of any importance. :For convenience of reference I have num~oered the beds all through, but the clays or silts whibh fall under the figures 4, 6, and 8 are practically identical. The greatest thicknessseen amounted to about 35 feet. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

4. Over the eastern and southern parts of the excavation, a thick- ness of blue silt ranging from 1 to 6 feet lies next below the recent tidal deposits, but on the north-western side, the tidal erosion having been somewhat greater, this uppermost silt has been washed away and the tidal deposits rest directly upon the peat-bed no. 5. The silt, like the others to be described, is crowded throughout with the roots and rotten stems of sedges in the position of growth, while at the bottom a few foraminifera (see Appendix, p. 485) give the oO .v-4 deposit a slightly estuarine character. 5. This peat-bed forms one of the most conspicuous bands in the series. It ranges from 1 to 2 feet in thickness and persists over the whole of the excavation (and, as I was informed by ~[r. Storrie, through the old dock also) except in those parts where the rock-surface rises in one of the shoals referred to. In such cases the peat-bed, slightly rising as it approaches the rock, thins away to a feather-edge, but comes in again at its proper level as the rock-surface falls. It keeps at a fairly constant level of about 4 feet below Ordnance-datum. Where fully developed it presents the following details :-- 5a. Laminated peat with logs (including, according to ~Ir. Storrie, willow, fir, and oak), passing down into 5 b. Light-eoloured flexible marl, composed of the shells of ostra- coda with much vegetable matter. 5 c. Shell-marl composed princi- pally of the shells of Limn~a, Bythinia, etc., with many ostra- coda and much vegetable matter, 5 d. Peat with logs of oak, etc. (one measuring 5 feet in length by Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

Vol. 5z.J 8UBME11GSDLA~D-SU~FXCES AT ZXRRr. 479

10 inches in diameter). A Neolithic worked flint was found by Mr. Storrie in this bed. 9The ostracod- and shell-marls occurring in this peat are best developed in the southern angle of the excavatiou. As the peat-bed approaches the flanks of one of the rock-shoals previously referred to, it curves slightly upward, and in such cases the shel]?-marls thin out; at the same time logs of wood become more abundant. It may be supposed that these slightly inclined portions of the peat; were formed at the margin of the water in which the shell-marls were accumulating, and that the logs were stranded in the positions which they now occupy. The worked flint referred to was found by Mr. John Storrie after I had left the district. He picked it out from the peat (5 d), three inches below the shell-marl, and within half a yard of it noted a stone containing glaucouitie grains in the shell-marl (5@ The implement is made from a light grey chalk-flint, derived possibly from the drift-deposits of the district. Sir John Evans, to whom I showed the specimen, determined it to be a broken fragment of a polished celt, and Prof. Hughes further pointed out to me that it seems to have been used subsequently as a strike-a-light. The fragment is only about an inch long, but shows parts of the two ground faces of the celt, and of one of the ground edges ; it can be matched exactly in shape (and, as it happens, in colour) by a polished celt from Mildenhall in Suffolk, which was given me for comparison by Prof. Hughes. It may be mentioned here that two bone-needlefi, now in the Cardiff Museum, are said to have been found in this peat-bed during the construction of the first Barry Dock. The only bone which I have seen or heard of was a fragment of an antler, probably of red deer, which had been thrown aside by the workmen. It clearly came from some part of the freshwater series. The ostraeod-marl (5 b) has been examined for me by Prof. Rupert Jones, F.R.S., who furnishes the full list of forms given in the Appendix. The brackish or freshwater Gytheridea teresa, Jones, forms the bulk of the deposit. The shell-marl (5 c) is considered by Mr. Clement. Reid to have been formed in a nearly freshwater tidal marsh. It consists mainly of Limncea and decayed Chara. He determines also the following shells and plants :~ Suecinea elegans. Bythinia tentaculata. Velletia laeastris. Entomostraca. Limn~a auricularia. peregra. Planorbis albus. Al, riplex. .... nautile~ts. Salix. ---- nitidus. Po~amogeton. ~ralvata piscinalis. ~Vaias marina. cristata. Chara, two species. Mr. Reid 9remarks that the occurrence of the pine (as identified by Mr. Storrie) and of Naias marina, both plants unknown in during the historic period, suffices to distinguish this peat from any recent deposit. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

480 ~R. A. STRAltAI~ 0~ SUBMERGED LAND-SURFACES [Aug. x896v

6. This blue silty clay precisely resembles no. 4. It ranges from 5 to 7 feet in thickness. 7. The second peat is an impersistent brown band never exceeding 8 inches, and averaging about 3 inches in thickness. Its upper and lower limits are indefinite, and it suggests merely that for the time being plant-remains were accumulating more rapidly than mud. :Mr. Reid describes i~ as 'a marsh-peaty apparently composed mainly of sedges (Svirpus rnaritimus).' 8. This resembles nos. 6 and 4, and is from 5 to 7 feet thick. In its upper part, immediately under the peat-bed no. 7, it con- tains shells, among which Mr. Reid identifies .Melam_pu8 myosotis, Helix arbustorum, Puloa, and Hydrobia ventosa. Upright stems of a sedge, probably Svirpus maritimus, occur throughout this bed as through all the other silts. 9. This peat occurs at or close to the bottom of the dock--~hat is, at; 20 feet below Ordnance-datum. It rarely exceeds 8 inches ia thickness, but is persistent. In several places it is made up almost entirely of large timber, both trunks and stools of trees~ while in one section roots and rootlets extending downward from the peat into a soil composed of disintegrated Keuper Marl were finely displayed. I give the section at this point, in full :-- ~ec,tion about the middle of the North-western side of the Dock. feet. inches, 2. Brown clay with Scrobicularia...... 0 to 1 0 3. Sand and gravel with recent marine shells...... 5 0 Line of erosion. 5. Peat ...... 1 6 6. Blue silty clay ...... 7 0 7. Peat ...... 3 to 4 8. Blue silty clay ...... 9. Peat with large logs, including some'of oak":::...... ::::..:: 5 3to8 0 Decomposed green Keuper Marls, traversed by roots in position of growth and joining on to the peat above. Among the roots are some of conifers ...... 3 0

Close by ~his spot the rock-surface rises on the flanks of on~ of the shoals referred to above ;, the beds thin out in succession against this slope (as shown in the section on p. 478), and it is fbr this reason that the sequence ends here with No. 9. The clear exposure left no doubt that the roots and rootlets were embedded in the position of growth in their native soil, nor was there any difficulty in tracing them upward into the mass of rotten wood that constituted the peat. In examining this section I had the advantage of the assistance of Mr. Storrie, to whom I am indebted for the identification of the woods. Mr. Reid describes a specimen of this peat collected fat a few yards distance as consisting of 'a tough mass of vegetable matter, principally sallow and reed, both roots and s~ems. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

Vol. 52.J x'c BA~R~, Qr.A~0RG~NS~mP.. 48Z

It also contains seeds of Waleriana o.]]ioinalis and Carex, and elytra of beetles. There is no evidence of sal~ water.' I infer that the peat was formed in the one case as a true forest-bed along the margin of a swamp, and in the other by the growth of water-weeds within the limits of the morass. 10 and 11. These strata lay below the dock-bottom and werer exposed only in the excavation for the foundations of walls, etc. :Fortunately a good exposure of the important part of them was accessible about halfway between the entrance and the southern angle of the dock. The section commenced at the dock-bottom~that is, at the peat last described (no. 9) ; in th~ upper part it was timbered up, but at a depth of about 9 feet, blue silty clay (no. 10)of the usual character could be seen and dug out through the timbers ; at 12 feet below the dock-bottom the silt was succeeded by peat no. 11, and from here downward. the section was open.

Section below the Dock-bottom south of the Entrance. feet. inches. f Not seen, but according to information all blue silty clay. 10 0 10. Blue and greenish silt, full of reeds and eontMning leaves and land-shells ; in the upper part foraminifera 2 0 ll. Peat with much timber ...... ~...... 3 4 12. Reddish clayey gravel with land-shells and penetrated by roots in place; passing down into red and green grits, limestone, and marls. With the exception of the foraminifera from the lower part; of the silt (no. 10), there is nothing in this section to suggest th~ presence of salt or brackish water. The list of the microscopic organisms is contributed in the Appendix with the remark that th~ bed is quite marine, but the molluscs and plants enumerated below seem to modify this conelusi, m. The red clayey gravel below was an unstratified deposit, including large angular fragments of the underlying rock. It was traverse4 by a network of roots ranging up to 3 inches in diameter, one of which at least was connected with one of the masses of wood in the peat above. Some of them also had moulded themselves against or between the angular blocks of rock, as would happen with roots growing in such a soil. Many had small twigs attached them, while much of the deposit was'more or less traversed by root-fibres. Some roots ran horizontally, but many vertically, and of the latter several were followed .down for 3 feet below the base of the peat without reaching their termitlations. The rock at this point is rising somewhat sharply, so much so that within 50 yards it touches the Upper Peat (no. 5), as shown in the section on p. 478. It might, therefore, have yielded some talus, but the gravel was totally unstratified and seemed rather to be rock decom- posed in place. The evidence leaves no room for doubt that this peat is an old land-surface, lying at a depth of 35 feet below ther present 0rdnance-datum. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

482 ~R. A. SrRARAN ON SU~tERS~J) LX,~D-SURSACSS [Aug. I896 '

Mr. Clement Reid furnishes me with the following information 9especting these deposits :-- 10. This greenish sandy silt is full of reeds and contains leaves of willow, and land- and freshwater shells, such as Limncea auricularia, Planorbis albus, P. nautileus, Hydrobia veutrosa, Valvata piscinalis, and /7". cristata ; Salix ~prvea and Phrag- mites. 11. This peat contains much broken oak-wood, mixed with seeds and shells, Hyalinia (Zonites), etc. A thin seam is full of willow-leaves and contains ostracoda, Hyalinia, and apparently Pisidi~m~ and Planorbis; the shells are much crushed. Oak, Quercus robur (wood). Hazel, Corylus avellana (twigs and nut). Cornel, Corn~s sanguinea (seeds). Hawthorn, Crat~gus oxyacantha (seeds). Bur-reed, STarganium (seeds). Sallow, 8ali.v caTra~a (leaves). 12. This old soil contains :- Bird (femur of small species about the size of the stint). Charychium minimum. Pupa. Helix arbu~storum. Valvata Tiscinalis. -- rot~ndala. Cardium edule, two fragments hisTida. (? brought by gulls). Hyalinia. Crat~gus oxyacantha (seed). Succi1~ea. Gornus sanguinea (seed). Limn~a truncatula. Quercus rebut (wood). Mr. Reid concludes from his examination of the specimens that the lowest land-surface represents a true forest-growth, such as could only live at an elevation clear of the highest tides ; one tide in the year would have sufficed to alter markedly the character of the fauna and flora in the deposit. Subsequently to the growth of this oak-forest a slow subsidence seems to have taken place, turning the land-surface into a shallow lake full of reeds and freshwater shells, the only indication of any salt being the occurrence of Hydrobia ventrosa, a shell which is seldom found in purely fresh water, and the foraminifera enumerated in the Appendix. The third peat (no. 9) Mr. Reid judges from the specimen submitted to him to indicate swampy ground rather than a true land-surface, but it will be remembered that in another section the existence of roots in place beneath the bed was clearly shown. The silt above (no. 8) be judges t~) be estuarine in its upper part, where it yielded fora- minifera, ~lelampus myosotis, Hyclrobia ventrosa, Helix arbustorum, and Papa, while the peat (no. 7) he considers to be a compressed mass of sedges and not a land-surface. Of the highest peat (no. 5) Mr. Reid remarks that the contained fossils suggest at first a purely freshwater origin, but closer examination shows a noticeable absence of all species that are sensitive to the addition of a little salt, and one of the plants, iYaias marina, is usually found within the reach of an occasional tide. The Igaias, he points out, is of special interest, for at the present day it is known from Britain in one locality only, in Norfolk, though it occurs also in the Cromer Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016 u 5z.] AT ~AR~Y, OLA~OR~A~s~ra~. 483

Forest Bed. Its recent distribution on the Continent is also very partial, but it~ seeds have lately been noted in abundance in. peaty deposits, perhaps of the same age as those of Barry, in parts of Sweden and Holstein. Mr. Reid remarks also that there is nothing in the fauna or flora to indicate any change of climate.

The facts detailed above seem to admit of but one explanation, namely, that the land has subsided at least 55 feet since the forma- tion of peat no. 11. In dealing with such deposits we have to bear in mind that the sea is capable of raising barriers against if~elf, and that behind such barriers freshwater deposits may be forming, or even a land-surface may exist at a level below that of the highest tides, though never below mean sea-leveL As bearing on thi, question I have noted from the 0rdnance-map the levels of some: of the marshes now bordering the Bristol Channel :- Feet above Ordnance-datum. Sully Moors, the alluvial flat of the Cadoxton River, 1 mile above Barry ...... 18 Cardiff (Grange Town), near the Taft River ...... 18 Cardiff East Moors ...... 20 to 22 .... , near the Rhymney River ...... 18 Cardiff (Cooper s Fields) ...... 25 Peterstoae Wentloog, 1 mile N.W. of ...... 15 .... 1 mile N.E. or, and near a ' gout ' ...... 13 In all these cases, except perhaps the Cooper's Fields, the tide~ would occasionally overflow the land, were it not artificially kept~ out. Assuming for the sake of argument that a surface 20 feet above Ordnance-datum is the lowest that would now be safe from such periodic incursions of salt water, we have 55 feet as the difference in level between the land-surface, peat no. 11, and the lowest possible at the present day. At , 15 mile west of Barry, a small stream with an alluvial fiat about 150 yards broa~ debouches upon the shore. The sea has blocked the valley by a barrier of shingle, through which the fresh wager escapes by perco- lation. The alluvial flat is liable to floods, though not, I believe, through the incursion of salt water, but only by the pending back of the fresh. The level of this marsh is about 40 feet abova Ordnance-datum, or 75 feet above the lowest peat (no. ll) of Barry Dock. In none of these alluvial flats, nor elsewhere in the Bristol Channel, do we approach conditions under which the Barry Dock deposits could have been formed. If we assume that the sea had raised against itself an effectual barrier at the mouth of the Cadoxton River, and that it had not yet gained access to the river-valley by the gap on the eastern side of the island, we must then allow the existence of a freshwater lake, for the land-water would accumulate behind the barrier to at least mean sea-level. That is to say, we should have to assume that water stood at a depth of over 36 fee~; ~vhere we find evidence of a land-surface, with forest tree~ grawing Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

484 SVB~RGSDv.Am3-SURFAC~ AT BARRr. [Aug. t896,

in place and abundant land-shells. The same sort of evidence, in a scarcely less striking degree, is presented by every layer from the bottom to the very top of the series. There is, in fact, no part of it that could be formed with the land at its present level. It will be noticed that the Cadoxton River flows for much of its ~ourse over Keuper Marls and the conglomerate or limestone which form the base of that series, but that at the coast it traverses the ~arboniferous Limestone. In the softer rock its valley is broad and occupied by the alluvial flat, of which the Sully and Cadoxton 3[oors form part, but in the Carboniferous Limestone it narrows down to about 100 yards. It was in this broad area of obstructed ~trainage that the deposits described above accumulated, and no doubt the regularity with which they were laid down, and the gentleness with which estuarine influence was occasionally in- sinuated, was largely due to the narrowness of the outlet. /it the time of the earliest land-surface, when the land stood not less than 55 feet higher than at present, the sea must have been still farlher removed, but how much farther it is not possible to say. Though the Carboniferous Limestone would waste with extreme slowness, there may have been extensive post-Glacial deposits outside Barry Island, of which the Bristol Channel tides would make short work, so that it is doubtful how far the contours of the present sea-bottom are those of a submerged.land-surface, or to what extent lhey have been modified by marine erosion. It is worth noticing that the only part of the Bristol Channel, south and east of Barry, which exceeds 60 feet in depth is" a rather narrow trough about 2 miles south of the Welsh coast. At any rat~3, we may suppose that the alluvial fiat, of the Sully and Cadoxton Moors occupies what was a generally freshwater estuary, occasionally dry enough to support a fores~growth on its margins, but as a rule swampy and densely overgrown with sedges, ~3tc. By a more or less continuous sinking of the land the swamp tended to become a shallow lake, nearly but not wholly beyond the reach of the tide, until the subsidence admitted the sea by the gap ~3ast of Barry, ~hus separating that island from the mainland, and burying the estuarine series under true marine and tidal muds. 'The occurrence of the fragment of a polished flint-implement in the uppermost peat proves that the subsidence was in progress in Neolithic times, but had not yet sufficed to insulate Barry Island.

In conclusion, I should mention that~ there is a copious literature ~n both submerged forests and raised beaches in the Bristol Channel. The re-survey of the district, however, by ghe Geological Smwey ]~eing in progress, I hope t~hat much fresh information will be forth- coming, and I have confined myself to a description of the one section that I have had an opportunity of examining, more especially as that section seemed unusually completo in itself. In dealing with ~he subject generally, both the earlier upward movement iml,lied by the raised beaches, and the later downward movement proved by the submerged land-surfaces, I shall hope to do full justice to my numerous predecessors. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

".Vol. 5z.] ~ICaOZOA rxo~ BXX~X nocx. 485

APPENDIX. I~EPORT On She MICROZOA ~ MARL a~ SILTS from BAI~RY DocK, ~e~" CARDIFF. [This has been drawn up by Mr. FaEDE~ICK CHAPMAN, A.L.S., F.R.M.S., with the advice and co-operation of Prof. T. RUPERT JONES~ F,R.S., F.G.S.] A. OSTRACODA. (1) From the Clay above Upper Peat (No. 4 of p. 478). 1. CYTHER1DEATOROSA (Jones), var. TE2Es, :Brady and ttobertson. See above, p. 479. This has been previously recorded from Cardiff (New Dock Basin). Two specimens. 2. LOXOCONCHAELLIPTICA, G. S. Brady. L. elZit)tica, G. S. Brady, 1868, Trans. Linn. Soc. vol. xxvi. p. 435, p1. xxvii, figs. 38, 39, 45-48; pl. xl. fig. % Previously recorded from Cardiff (New Dock Basin). Frequent.

(2) From the Upper Peat (No. 5 b of p. 478). 1. CA~DO~APUBESC~,NS (Koch). ' ay.pris pubescens, Koch, 1837, 'Deutschlands Crustaceen,' etc. ~fteft xi. p. 5. Gypris setigera, Jones, 1857, Monogr. Tert. Entom. (Pal. Soc.) p. 12, pl. i. fig. 6. Candona compressa, Brady, 1868, Trans. Linn. Soc. vol. xxvi, p. 382, pl. xxvi. figs. 22-27. Oandona pubescens, Brady & Norman, 1889, Sci. Trans. R. Dublin Soe. ser 2, vol. iv. p. 101, pl. xii. figs. 32-37 (limbs, etc.). This species has been recorded from post-Tertiary deposits in Berkshire and Cambridgeshire; and it occurs as a recent fresh- water form in Great Britain and Europe. Examples still bearing the short bristles on the exterior of the ~alves are found in the deposit from Barry Dock. Frequent. .~. CANDO~ASUB~EQUALIS, Jones. O. subo~qua~is, Jones, 1857, ~onogr. Ter~. Entom. (Pal. Soc.) p. 20, pl. i. figs. 9 a-c. This is already known as a post-Tertiary freshwater form from ~Essex. Two specimens ; Barry Dock. S. CA~0NA eA~DIDA (Mfiller). .Oypris candida, Miiller, !785, Entom., etc. p. 62, pl. vi. figs. 7-9. Candona candida, Baird, 1845, Trans. Berwick. Nat. Club, vol. ii, p. 153 ; Jones, 1857, Monogr. Tert,. Entom. (Pal. Sot.) p. 19, pl. i. tlgs. 8a~-f; BraSy and Norman, Sci. Trans. R. Dublin Soc. set. 2, vol. iv. 1889, p. 98, pl. x. figs. 1, 2, & 14-23 (including varieties). Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

486 M~. F. C~APXAZ~A~V PRO~. T. R. JON~S [Aug. I896 r A Pliocene, post-Tertiary, and recent freshwater species. Frequent, Barry Dock. 4. C~oNA T.ACrSA, Baird. ~andona l~tea, Brady and Norman, 1889, Sci. Trans. R. Dublia Soc. ser. 2, vol. iv. p. 100. A post-Tertiary and recent freshwater species; Great Britain and Europe. Frequent ; Barry Dock. 5. DA~W~I~VLAST]~VE~SO~I, Brady and Robertson. Daru, i~elh~ StevensonX, Brady and l~obertson, 1874, ~[onogr. post- Tert. ]~ntom. (Pal. Sot.) p. 141, pl. ii. figs. 13-17. .Darwinula Stevensoni, Brady and Norman, 1889, Sci. Trans. It. Dublin Soc. ser. 2, vol. iv. p. 12Z, pl. x. figs. 7-13. A Pliocene, post-Tertiary, and recent freshwater species ; Grea~ Britain and Europe. Common ; Barry Dock. 6. LIM~IC~THV.r~n~oP1~ATA(Baird). Limnicythere inopinata, Brady, 1868, Trans. Linn. Soc. vol. xxv. p. 419, p1. xxix. figs. 15-18, pl. xxxviii, fig. 9, pl. xxxix, fig. 1. This strikingly sculptured species is a pest-Tertiary and recenb form; inhabiting fresh and estuarine waters, and found sometimes in seawater near the coast. Very common ; Barry Dock. 7. CYTHE~rDSA ~OROSA(Jones), vat. TER]~S, Brady and Robertson. G. torosa, var. teres, Brady and Robertson, Ann. ]Wag. Nat. Hist, 1870, ser. 4, vol. vii. pp. 21, 22; Brady, Crosskey, and Robertson, 1874, ~[onogr. Post-tert. Entom. p. 178, pl. vii. figs. 1, 2. This variety is distinguished from the type by the absence of the knobs so conspicuous in O. torosa. The specimens here under notice vary very much in size, measuring ~ to rl~ inch (0"42 ram. to 1"38 ram.) in length. The external surfaces of the valves are marked with minute pittings, disposed in a somewhat concentrically lineat~ manner. The usual transverse median sulcus is well-marked in nearly all the specimens, but it is better developed in the larger individuals. There is a short stout spine on the margin of the right valve at the posterior ventral angle. The valves of ~he male ara narrower and more elongate than those of the female. Previously known as a Pliocene, post-Tertiary, and recent fresh- water and estuarine form; Great Britain and Europe. Very abundant ; Barry Dock. (3) From the Clay above the Lowest Peat (No. 10 of po 481). 1. C~H]~R~. PELT.UCXVA,Baird. ~. pelludda, Brady and Norman, 1889, Sci. Trans. R. Dublin Soc. set. 2, vol. iv. p. 126, p1. xiv. figs. 13-15. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

Vol. 5z.] oN I,,~ ~ICaOZOA FaOM B~RR:r DOCX. 487 This is an essentially brackish-water species, and has been before recorded from Cardiff (New Dock Basin) amongst other places. Commoll. 2. CYTHERURA PRODUCTA, G. S. Brady. (5'. producta, G. S. Brady, 1868, Trans. Linn. See. vol. xxvi. p. 443, pl. xxxii, figs. 60, 61. This species has been previously found at Cardiff (New Dock Basin). One specimen.

~. FORAMINIFERA.

From Clay From From Clay (Nol0) (No. 4) above Upper above Lowest Peat Peat. Upper Peat. (~o. 5 b)

Miliolina oblon#a (Montagu) .. ... ,.. 2 subrotunda (Montagu) ...... o. 1 Cornuspira involvens, Reuss ...... ,~ 3 Trochammina inflata (Montagu) . Frequent. o.. 1 , vat. macrescens, ]3] H. 1 3 Brady. Textularia trochus, d'Orbigny ... ..~ ~ 1 small specimen. 3~olivina gextularioiztes, Reuss ... .~176 ~ Common. zLagena globosa (Montagu) ..... ~ 1 1 - lcevis (Moutagu) ...... 1 Pol~tmorThina lac~ea (W. & J.) .. ,~ 1 small specimen. .Discorbina rosacea (d'Orb.) .... ,~176 1 2 Bertheloti (d'Orb.) ...... 1 --- obtu~sa (d'Orb.) ...... 1 1 Truncalulina ~n.qeria~a (d'Orb.) ... 1 Rotalia Beccarii (Linn6 ). Dwarfed Common. 2 Frequent. specimens. 2%nionina depressula (W. & J.)... Cornmen. Very common. Polystomella striatopunctata (F. Very common. 9 1 Yery common. a M.). jBendroThora erecta (Str. Wright) ~requent.

1..9 DENDROPltRYA EREeTA, Strethill Wright. Dendrophyra erecta, Str. Wright, ]861, Ann. & Mag. Nat. Hist. ser. 3, vol. viii. p. 122, pl. iv. figs. 4 & 5. Fragments of tubes, composed of loose sandy materiall and usually tapering at one end, after the manner of the above form. There can be hardly any doubt, that these post-Tertiary specimens are referable to the above species. Frequent ; Barry Dock. 2. L,~NA L~vIs (Montagu). Lagena lcevis, Williamson, 1848, Ann. & Mag. Nat. Hist. ser. 2, vol. i. p. 12, pl. i. figs. 1 & 2. A very minute, but perfect, example of this species; from Barry Dock. Q. J. G. S. No. 207. 2r. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

488 :MR. A. STRAHAN ON SUBMEROED LAND-SURFACES [Aug. I896

3. LAGENA GLOBOSA (Mont, agu). Entosolenia globosa, Parker and Joue% 1857, Ann. & Mag. Nat. Hist. ser. 2, vol. xix. p. 278, pl. xi. figs. 25-29. Lagena globosa, Reuss, 1868, Sitzungsb. k. Akad. Wiss. Wien, vol. xlvi. p. 318, pl. i. figs. 1-3. A very small individual; from Barry Dock. 4. DISCORBIN~ R0SACEX (d'Orb.). Discorbina rosacea, Parker, Jones and Brady, 1865, Ann. & Mag. Nat. Hist. ser. 3, vol. xvi. p. 25, pl. ii. fig. 71. One specimen, of fair size ; Barry Dock. 5. DISCO~BI~A OBTUSA(d'Orb.). Discorbina obtusa, Brady, 1884, Rep. Chall. Foram. p. 644, pl. xci. fig. 9. A young example of this form, with but few chambers. One specimen ; Barry Dock. 6. Ro~ALIA BECC~RII (Linn6). .Rotalia Beccarii, Brady, 1884, Rep. Chall. Foram. p. 704, pl. evil. figs. 2 & 3. Young specimens, but typical. Two examples; Barry Dock. 7. POL~STOMELLAS~RIX'~OPU~CTATX (Fichtel and Moll). Polys:omella striato_punctata, Brady, Rep. Chall. Foram. p. 733, pl. eix. figs. 22, 23. One specimen, of rather small size ; Barry Dock.

C. PLANT2E. From the Upper Peat (No. 5 b of p. 478). Nucules and stem-fragments of Chara, sp. ; Cam_pylodiscus (Dia- tomacem).

From the Clay above the Lowest Peat (zNo. 10 of p. 481). Camloylodiscus. Frequent. The lowest portion is quite marine ; the higher upward one goes the more estuarine the material becomes.

Dtscw SION. Prof. T. RVP~T JONES referred to the importance of foraminifera as giving evidence of the presence of sea-water ; and stated that some of the entomostraca ~rom the ostracod-marl had a brackish-water habitat,. He mentioned that the examination of the specimens was made by Mr. Chapman, and that he had only given help and advice. The "PRESIDENTsaid that the paper was of much interest to him, Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 15, 2016

VO1. ~2.] AT BAR~, SLAMO~S:~S~RE. 489 as he had during many years past paid considerable attention to the submerged forests and peat-beds which have been found along the Welsh coast of the Bristol and St. George's Channels. Some sub- merged forests were noticed by the historian Giraldus Cambrensis in the 12th century, at spots now constantly covered by the sea; and there is other evidence to show that great encroaehments have taken place in comparatively recent times. When the forests which contained oak, alder, birch, etc. as their chief trees, grew on the plains and in the valleys exposed to the westerly winds, it is clear that the sea must have been at a considerable distance ; and it seems more th~n probable that the :Bristol Channel was then mainly a tract of marshy plains traversed by important rivers. The trees in the forest at Whitesand Bay, Pembrokeshire, which he examined many years ago, had been deeply rooted ill the underlying Boulder Clay, and many antlers of the red deer, a jaw of the brown bear, and a well-worked flint-flake were found by him in the peat-bed. Possibly the oldest of the beds referred to by the Aulhor might belong to the same period, but the others appear to be of more recent date. Mr. CO~)RINGTO~ said that the old beds of the river and ' pills' along the Coast indicated subsidence at least as great as 55 feet. The rock- bed of the Wye at Chet~stow was 42 feet below low water, having 40 to 50 feet of mud over it eont~dning nuts, leaves, and oak-timber. In Milford Haven the rock-bottom of Myland Pill was 45 fee~ below low water, and that of the channel of the pill at Milford Docks deeper still, with 40 to 50 or 60 feet of mud. There were many such sections. The AC~HOR replied to Prof. Jones that he had acknowledged the occasional invasion of the estuary by salt or brackish water, implied by the presence of foraminifera and some of the ostracoda. At the same time the entire absence from the estuarirm beds of the marine shells which abounded in the overlying deposits was significant. The hypothesis of the President, that when the lowest peat was being formed the Bristol Channel was dry lzmd traversed by a winding river had occurred to him also, and it was with this in mind that he had pointed out the existence of a deep narrow channel about 2 miles south of Barry. The relative levels of the peat-beds and the sea could not be explained by more encroachment of the latter. ~o glacial deposits occurred either in the excavations or in the immediate neighbourhood. The existence of the numerous buried valleys referred to by Mr. Codrington, and the general character of the deposits filling them, were well known to him. They had been explored, however, chiefly by borings, and he attached greater value to observations made on such deposits in situ, and to specimens collected with every precaution against the mixing of the fauna and flora of different beds, than to the mangled dgbris brought up by the boring-tool.

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