Foraminiferal, High-Level Boulder Clay, in the County of Dublin, and in Dumfrieshire and Ayrshire; With Observations on the Origin of Boulder Clays

Foraminiferal, High-Level Boulder Clay, in the County of Dublin, and in Dumfrieshire andAyrshire; With Observations on the Origin of Boulder ClaysAuthor(s): Joseph WrightSource: The Irish Naturalist, Vol. 12, No. 7 (Jul., 1903), pp. 173-180Published by: Irish Naturalists' Journal Ltd.Stable URL: http://www.jstor.org/stable/25522369 .

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JUIY, 1903. '7

FORAMINIFERAL, HIGH-LEVEL BOULDER CLAY, IN THE COUNTY OF DUBLIN,

AND IN DUMFRIESHIRE AND AYRSHIRE;

WITH OBSIRVATIONS ON THE ORIGIN dO BOUTLDErR -CLAYS.

BY JOSEPH WRIGHT, P.G.S.

IN 1873 Rev. Maxwell Close r.s., read a paper before the

Royal Gleological Society of Ireland, on "The Elevated Shell

bearing Gravels near Dublin."' In this paper the author. records the occurrence of molluscan shells- in the sand and

gravel beds at Ballyedmoilduff, at an elevation of i,0ooo.feet above the sea, and at Caldwell Castle, at an elevation of 1,200 feet. Five years later I visited the former locality, and

brought away a small quantity. of, the finest of the material for microscopical examination; the shell fragments through it were much worn' by exposure to the weather.2 The. fol lowing Foraminifera were obtained:

MYillolina Boueana (d'Orb.) ?-Rare.

Polystomella crispa (Linnd).-Rare. P. striato-punctata (F. & M.).-Rare.

Nonion ma ciepressula (W. &J.).-Common. A few months ago I received from Mr. H. J. Seymohr, of

t-he Geological Survey of Ire and, two packets of Boulder clay, which he kindly got for me from Mr. J. de Witt Finch of the National Library, Dublin. They were from Rockbrook

and Larch Hill, Countv Dublin.3 The following is a list of

the Forarainifera RocKxROOK.

Boulder clay, Rockbrook, 500 feet above the sea. Weight of clay, 24-8 oz. Troy; After washing, 7u2 OZ. fine, 4 oz, coarse,4 stones angular and rounded, some of them very much rounded as if they had been, so

formed on an exposed sea beach. Foraminifera most a-bundant..

WlIliolina seminulum (Linn4).-Very rare.' Verneuilina pygmea (Egger).-Very rare..

1 Journ. Roy. Geol. Soc. Areland, vol. iv., new series. pp.- 3-64, I873-77.

2 Proc. Belfast Nat. Field Club, I879-80, app., p. I56.

For information regarding these clays, see "A Contributio'n;to Glacial Geology of County Dublin," by J. de Witt Hinch, Irish -Naturalist,

October, 1902. 4 The sieves used for washing the clays were a galvanized- wire sieve,

I6 meshes to the linear inch, and a miller's silk 4w i xs s hie the -tbte

linear inch, A



174 The Irish Naturalist. July,

ullmlna marglnata, d'Orb.-Very rare.

B. elegantissglma, d'Orb.-Very rare.

B. fustformls, Will.-Very rare.

Bollvlna dl latata, Rss.-Very rare.

B, text! larloides, Rss.--Very rare.

B. plicata, d'Orb.-Common.

Cassiclu l na crassa, d'Orb.-Comnmnou.

Lagena globosa (Montag.).-Very rare.

L. ctepressa, Chaster.-Very rare.

J.. ineata (Will.).-Very rare.

L. sulcata (W. & J.).-Very rare.

L. imarglnata (W. & B.).-Rare.

L. iucida (Will.).-Very rare.

Uvlgetrina angu-Iosa, Will.-Rare.

Globigerlna bulloldes, d'Orb.-Common.

Orbuilna tiniversa, d'Orb.-Frequent.

Dlscorbina obtusa (d'Orb.t.-Common.

0. mlnutissimaa, Chaster.-Very rare.

D. rosacea (d'Orb.).-Very rare.

Truncatullna Iobatula (W. &J.).-Rare.

Pulvinuitna KarstenI (Rss.).-Very rare.

Nor.lonina depressula (W. & J.).-Most abundant.

PolystomelIa striato-puntetata (F. & M.).-Rare.

Five hundred and sixty specimens of Nonionina depressula were obtained

from this gdthering, whilst the remaining 24 species niumbered only 201

specimens. Lagena depressa was by far the most interesting species; only

one specimen was found.

LARCH HILL.

Boulder clay, associated with shell-bearinig gravel. Larch Hill, 65o feet

above the sea. Weight of clay, 21V3 oz. Troy. After washing, 9q2 oz.

fine; -oo3 oz. coarse; a few very minute stones more or less rounded.

,oraminifera most abundant.

MllIolina sem.nutum (Linnd).-Very rare.

Verneutlina pygmaea (Egger).-Rare.

V. spinulosa, Rss.-Very rare.

Textularla globulosa, Ehr.-Rare.

Bullm na pupoldes, d'Orb.-Rare.

B. eivgantlssima, d'Orb.-Very rare.

B. fusiformis, Will.-Frequent.

Bollvlna punctata, d'Orb.-Frequent.

B. dltatata, Rss.-Rare.

B3, textilarlocles, Rss.-Very rare.

B. plicata, d'Orb.-Very common.

.C,assidulina crassa, d'Orb.-Very common.

-Lagena globosa (Montag.).-Very rare

Le apiculata, Rss. ?.--Very rare.



1903. WRIGHw.-Foramninf/eral Boulder-clay. T

Lagna lovls (lontag.).-Very rare. L. meMistriata, Will.-Very rare. L. lineata (Will.).-Very rare. Lo Ivevlgata (Rss.).-Rare. L. marginata (W. & B.).-Frequent. L. Orbignyana (Seg.).-Very rare L. flmbriata, Br.-Very rare.

Nodosarla calomorpha, Rss.-Very rare. Uvigerina angulosa, Will.-Frequent. -

Olobfgerina buloidles, d'Orb.-Most abundant. 0. cretacea, d'Orb.-Rare. Orbbu 11 na un iversa, d'Orb.-Common. PatellIlna corrugata, Will.-Very rate. Discorblna globularis (d'Orb).-Very rare. D. obtusa (d'Orb,)._Cotnmmoi.

D. rosacea (d'Orb.).-Frequent.

D, m Inutissi ma, Chaster.-Very rare. D, tuberculata, B. & W.-Very rare.

Truncatulina lobatula (W. & J.).-Rare.

Pulvinullna auricula (F. & M.), var.-Very rare. P. Karatenl (Rss.).-Rare.

Rotalla Beccarll (bJinn,6).-Very rare.

Nonlonina depressula (W. & J.).-Most abundant.

N. pauperata, B. & W.-Very rare.

Polystomej la strlato-punctata. (F. & M.).-Very rare

Seven hundred and seventy specimens of Nonionina depressula were obtained from this gathering, whilst the remaining 38 species comiprised only 6oo specimlenis. Lagenta flmbiata. was the most interesting form; it has only beent met with as a recenit British species off the west coastsaof

Ireland and Scotland; it occurred in 30 of the Lord Bandon gatheriigs

from between tides to ea depth of 214 fathoms.

To Mr. Jonll Smith, of Monkreddinig, I ami mlluch indebted

for four samples of shelly Boulder clay fromi high levels in

Ayrshire and Dumfrieshire. A few years previously I had

examined, for Mr. T. Mellard Reade, v &.S4G five, samples of

Boulder Clay from Ayrshire, which he had- collected -in coin'

pany with Mr. Smith, who was the discoverer- of these fossili

ferous clays in this part of Scotland.' In four of the samples

Foraminifera were founid in more or less abundance--viz., at

Byne Hill Burn, i20 feet O.D., i,i6o specimens were ob

tainied; at Merkland Burn, 550 feet O.D., 22 specinmens; at

1Geological observatio'ns in Ayrsliire. Pr-oc. LivrolGo Sc

1i896-97, pp. 104- 129. 2 Drift or Glacial Deposits Qf Ayrshire. Trans.. Gept. $oe.; GZ(as~o v;

$uppleinent, vol xl., i898.



176 The Irish Naturalist. JulY,

Westown Burn, 500 feet O.D., I,443 specimens; and at Greenockmains, 6oo feet O.D., I2 specimens. The following

is a list of the Foramninifera froml the clays recently sent to

me by Mr. Smith

KILWINNING.

"Sanldy mud, in Boulder clay, the latter about 20 feet thick, Seven acres Quarry, under Kilwinninig, about 200 feet above-the sea." Weight of clay, 2I'5 Oz. Troy. After washing, 7 oz. fine; 3-4 oz. coarse; stones somiewhat rounded, shelL fragments frequent. Foraminifera plentiful.

Bolivina plIcata, d'Orb.-Rare. Cassidullna crassa, d'Orb.-Frequent. Lagena ? sp.-One specimen. Polymorphina lanceolata, Rss.--One large specimen. Globigerina bulloIdes, d'Orb.-Very rare. Discorbina obtusa (d,Orb.).-Rare. Truncatullna lobatu%a (W. & J.).-Very rare.

Nonlonina clepressula (W. &J.).-Very common.

- ~~~~~~THORNHIX<I,. "Boulder clay, Tansley Burn, three miles N.E. of Thornhill Station,

Dumfrieshire, i,ooo feet above the sea. Stones and boulders, many of them striated," Welght of clay, 25 5 oz. Tr'oy. After washing, 6-2 Oz. fine; 4 2 oz. coarse. Foraminifera rare.

Bullmina pupoldes, d'Orb.-Very rare.

S3l1vinaa plicata, d'Orb.-Very rare.

.CassldulEna crassa, d'Orb.-Very rare.

Globlgerlna bulloldes, d'Orb.-Rare.

Discorbina obtusa (d'Orb.).-Very rare.

Truncatulina lobatula (W. & J.). -Very rare.

Nonlonina depressula (W. &J.).-Very rare.

0 ~~~MUIRKIRK.

"Boulder Clay, Dippel Burn, near Muirkirk, Ayrshire, i,o6I feet above the sea." /Weight of clay, ito oz. Troy. After washing, 35 4 oz. fine-; 19'6 oz. coarse. Foraaminifera frequent.

Bilocullna ringens, (Lamk.).-Rare..

IvElol1na seminulum. (Linn4).-Rare. . .s ub rotuncla (Montag .).- Rare.

Oulmnina fusiformis, Will.-Very rare.. BolIlvIna punctata, d'Orb.-Very rare.

B. dilatata, Rss.-Very rare.

Cassidulina 1aevigata, d'Orb.-Very rmre, C, - crassa, .d'Orb.-Veryr rare

Lagena Isevigata, Rss.-Very rare.

Li ucdica (WiJl.).-Very rare. L. mnargtnata (W. & B)-Very rare,



1903. WRIrHnt-Foraminiferat touldler-clay. 177

Olobigerina bullolcies, d'Orb. -Very rare. Orbulina universa, d'Orb. -Very rare. Dlscorbina obtusa (d'Orb.).-Rare.

RotaIla orbicularls, d'Orb.-Very rare.

Nonionina depressula (W. & J.).-Common. Polystomella striato-punctata (F. & M.).-Rare.

P. subnodosa (Munster),-Very rare.

I received two packets of this clav. The first weighed 7I Oz; I found

in it only one solitary example of ZVo4ionina idepressla; the other, which

Mr. Smith informis me was collected about ioo yards distant from the

previous one, and weighed only 39 oz,, yielded 79 specimens. Much thq rarest form in this gathering was Poeystomnella subnodosa) as a recent British species it has only been found off the west coasts of Ireland and Scotland..

"Boulder clay, Leaze Burn, four miles N.E. of Muirkirk, Ayrslzire, 1,330 feet above the level of the sea, stones atnd boulders well striated."

Weight of clay, 781 oz. Troy. After washing. 23-6 oz. fine 202 o Z. coarse. Foraminifera rare.

Discorblna obtusa (d'Orb.).-Very rare. Nonlonine depressula (W. & J.).-Rare.

I received, two packets of this clay. In one of them I obtained seven specimens; in the other, only one specimen.

The occurrence of Foraminifera at such high elevations in

the County of Dublijn and in Ayrshire is very instructive, as

it shows that the land at these places as well as in Wales was

submerged to a great depth during the glacial period. Forami-X inifera have been found in the drift of Moel Tryfaen in Wales

at an elevation of I,350 feet, at Leaze Burn, Ayrshire, at I,330

feet, and at Ballyedmlonduff, Co. Dublin, at i,ooo feet, and

shell fragments were obtained in the gravels at Castlecaldwell, 2oo feet higher, but the gravel from this locality has not yet

been examined for Microzoa. In the " Memoir of the Country around Dublin, Explanation

of Sheet II2," recently published by the Geological Survey,

the writer of the part dealing with the origin. of the, glacial

deposits has attempted to explain that the idrifts as awhole, including those that contain shell fragments, have been de

posited by land ice and not during marine submergence-that

the shell-bearing clays and gravels have been shoved, up by

ice from the bed of the Irish Sea to their present elevation that this took place at a time when the basin of the Irish Sea

and the adjoining land was buried to a great depth nider lce that the fossil shells are always incomplete and generally mere

fragments, and that they are absent from the beds offine sand



178 Ehe frish Naturalist. July,

and stratified clay which are -imbedded with the Boulder clay

and gravels, with other observations supporting this conclu sion- of a similar purport.

The microscopical examination which I have made not only of the fossilif'rous' clays at Rockbrook and Larch Hill, but

also of Boulder clay from other localities, has led me to" a very

dilfe:rentO concltision as to the origin of these clays. No doubt there was, in glacial timies both elevation and subsidence;

arinst glaci striation, then depression, Boulder clay, and

hlaifile`lprgani!s'w ;

WThen the,writer refers to '"'the absence of shells fronm beds of fine sand and stratified clay, which are imbedded with Bduildet chy "lit mi-ght have added, "but in which other marine:organisms-otcur.' -It is the fine claywhich usually

yields Forantinifea in the greatest numbers. It was in such in:terstratified clay, both at Iarch Hill and also at Shellag, Isle

of Man, that Foraminifera occurred in such profusion. This Is- a-l-sd thie: da?e in r&cent marine sedimentary deposits, a soft oozy sea bottom is more favourable to maritne life, especially to toraifinifera, than- places that are more sandy and where

t-he t u-n-of the tides is stronger.- ; Many of the shells inl Boulder clay wefe transported by ice

bergs witli stones and rock fragments, but some of' them cer

tainly live-d at the places wherie they are now found, and with

So&d few e:xceptios`s all the Foraminifera must have done so, Ais thtey are usually as perfect and as fresh looking as recent

spetimens brought up by the dredge. Nor cant I agree with the writer that the Irish Sea and the

adjoining lanld was buried under such immense miasses of ice.

WhereAdid Tfhe vapour Come fronm to form these masses of ice,

seing that there cotuld be litt:le evaporation froni such a frozen

surface? -Eve-n presuming such a glacier did- exist cofiiing

ffr&n the -North Channel, its nlatural course would be south

ward by- St. George's Channel where thete would be least- re,

Jiistance, -and not- upwards over the land. I have examined micrtoscopically 134 samiples of Boulder;

cla-y rom11 various places i'n Ireland, England, Scotland, Canada,

And: Ndvaia Zemlia, and- in' 102 of these Foraminifera' have

been' f- und.- Specimens were got in all the 'samples, i6V- in

nu-mba; which I receiVed froni Novaia Zemlia.L These had all



1903. WRIGH1t -Foramin?feral Bou-ider-clay.

to be examined in detail under. the microscope, the -samples. being too small to be. treated in any other way. . Floatings, from the other clays were alone examined; in 3.2-Of these no organisms were found, this may in part be due. to the first" floatings alone being examined, also that these. mi-nute or-. ganisms are at times liable to be- overlooked when.- examining, the clay. To ascertain how far floatings.,could be relied.on.. for giving conclusive results, one ounce troy of the Boulder clay from Woodburn,. Carrickfergus,. was examined ,with great care. The first floating cotntained i,400 specimens, the .float ing process being repeated .25 times before specimens ceased. to come up. What remained of the clay was then examniined under the ,microscope, and 67 additional specimens got from it. Upwards of 2, I0o spe.cimens were obtained from this. ounce of-clay. This experiment clearly demonstrated that: the process of floating cannot be relied on for proving the. non-existence of Foraminifera in Boulder clay.

- The fau na- of the Boulder clav is a peculiar one; more than, half of-the entire specimens found are referable to Nonionina depressula and Cassididina crassa; the latter, which is .some-.

what rare as a recent British species, is often, plentiful in the

*clay. The porcellanous-forms are usually very rare, whilst the .Arenacea are represented only by the species HaplopAhragm1ium canariense. It is instructive to compare the numbe r of these: two sub-orders fronm dredgings taken. in the Irish Sea, with those that have been found at Larch Hil-l and Rockbrook.

Four small specimiiens of Miliolina serninulunm were: the only Porcellana founld in the Dublin clays, and there were no

Arenacea whereas, in the dredging taken_ off Dublin by Mr. F. P. Balkwill and myself,> 22 species -of the formiier wete ob

tained and I9 of the latter, these being represented by thou-. sands of specimens.

The marine fauna in a clinmate so rigorous as must have

prevailed during the glacial period, could not fail to be a poor one. Mr.. S. A. Stewart, in his " Mollusca of the Boulder Clay of. the North-East of Irelanid " says, "Molluscani shells

occurring. in.. the Boulder clay are not numerous; in most cases they are only got by patient searching, and theni only in a fragmentary condition, but in a few instances they are less

1 Trans. Roy. I. Acad., vol. xxviii. (Science), pp 317-365, 1885.



ISo The isAS Na?uraszT t. July;

rare, avid iliclude speeximens in. a perfect state. The presence of perfect shells of Leda was known lolng since to General Portlock, and forced himi to the same conielusion as arrived at

by-the author, that the Boulder Clas is a mnarine sedimentary deposit."17: At Woodburn and Knock Glen, Co. Down, Leda

minula and iL. Aygmea are usually found uninjured, and often with valves united. Here, alsto, Foraminifera occur in the very greatest profusion, ioo species hav7ing beein fouild at

Woodburn, and 79 at Knock Glen. The Foramiinifera in Boulder clay are usually much 'smaller in size than recent British species, but many of the specimens at these two localities 'attain fairly large proportions. This, no doubt, is due to,these clays having been deposited in deep and quiet

water, ;below th'e disturbing influence of ice action; it would also account for theP abundance of specimens, as well as for the smaller proportion of stones in the clay.

The occasional occurrence in Boulder clay of Foraminifera, which- are now only known as recent British species from collections off the west coast of Ireland, and, in one or two instances, off the west coast, of Scotland,-,is of great interest.

Three of these species have been found in the clay at Wood

burn, and five of them at Knock Glen. Some also have been got at- other localities, giving further proof that the Boulder

clay was in places deposited in deep water, where the marine

co-nditions miList have been somewhat similar to what now

prevail off the west coast of Ireland.

,:Should, at any future time, the sea-bed between Labrador and Greenland be raised above the sea, one can readily imagine such a place to present very similar appearances to those which we now find in Boulder clay. There would be rock fragments and stones striated and scored by ice action, associated with shells more or less broken with other material that Ihad been carried there by: icebergs floating southward from Arctic places, the rapidly melting bergs depositing their burden over -the sea bottom, and with these would be asso

ciated mud anid stones from the wearing of rocks in the

Vicinity, as well as the marinie organisms that lived at the place. -

Belfast

' Mhvrc. Bdfdsf Na. Zfide ClAb.-App.-1879-8Q



Documents

Foraminiferal, High-Level Boulder Clay, in the County of Dublin, and in Dumfrieshire and Ayrshire; With Observations on the Origin of Boulder Clays