The Strabane Lead Mine, Co. TyroneAuthor(s): R. A. OldSource: The Irish Naturalists' Journal, Vol. 18, No. 2 (Apr., 1974), pp. 41-43Published by: Irish Naturalists' Journal Ltd.Stable URL: http://www.jstor.org/stable/25537725 .

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In 1964 Meta menardi was found by the souterrain team in the following souterrains:?Dunluce Castle near Portrush, County Antrim; Bog Head and Donegore near Antrim town, County Antrim; St. Lasser's at Florencecourt, County Fermanagh; in Aghanaglack at Boho, County Fermanagh (Adair, 1973).

In 1964 and 1973 no cave spiders were seen in Knock Dhu Souterrain although they had been recorded there previously (see above). In 1973 the spiders were seen in

The Boho Caves and in Bog Head Souterrain. They were not seen in Donegore Souterrain nor in a souterrain at Castlewellan (see above).

The author has made extensive explorations in the caves and potholes of the Fermanagh, Cavan and Sligo districts. Much time has been spent searching for cave fauna. It is interesting to note how scarce Meta menardi is in the caves of these districts.

It is possible that flooding plays a major role in the suitability of a cave for habitation by the spider. It is noteworthy that the spider has not been found in the many larger^ cave systems which are not subject to flooding.

The size of the colonies found varied from about ten specimens in Bog Head Souterrain to upwards of ,50 specimens in St. Lasser's Souterrain.

In conclusion Carpenter's comment of 1898 is still applicable, that "this spider is evidently rare in Ireland, though it seems to be widely distributed".

Behavioural Note

Standen (1909) mentions that in the Dog's Hole Cave in Warton Crag in Lancashire the spiders are "not at all easy to capture

. . . extremely active, disappearing

into crevices when a light is thrown upon them". In the author's experience the Irish'

spiders show quite the opposite characteristics. They are readily captured. They react to sudden light only by pulling the legs closer to the body, and only move, albeit

rapidly, when actively disturbed. Within minutes of the disturbance ceasing the spiders return to their original positions.

A specimen in Aghanaglack Souterrain in 1973 was of particular interest. It had "tied up" in silk a live young earthworm about an inch and, a half long and was

hauling it up the web.

Acknowledgements

I wish to thank W. S. Wright, F.R.E.S., who identified Meta menardi (Latr.) and Dr C. Arme of the Department of Zoology, Queen's University, who read the

manuscript.

15 Sunningdale Drive, Newcastle, Co. Down.

REFERENCES Adair, F. O. (1973). Souterrain Survey, Second Report (In Press). See also unpublished

records in the Ulster Museum.

Carpenter, G. H. (1898). List of the spiders in Ireland. Proc. R. Ir. Acad. ($er. 3), 5:

128-210.

Jameson, H. L. (1896). On the explorations of the caves of Enniskillen and Michelstown.

Ir. Nat, 5: 93-100.

Pack-Beresford, !D. R. (1907). Contributions to the Natural History of Lambav: Araneida

Ir. Nat., 16: 61-65.

Standen, R. (1909). Notes on the Cave Spider, Meta menardi, Latr. Lanes. Nat., October.

Stendall, J. A. S. (1928). Cave spider in County Antrim. Ir. Nat. J., 2: 55 and 74.

THE STRABANE LEAD MINE, CO. TYRONE

R. A. Old

A small lead mine, long disused and previously unrecorded in geological literature has been discovered recently by the writer at Strabane, Co. Tyrone. In view or the continued interest in prospecting for base metals in Northern Ireland which is

being shown by mining companies, it is considered that a description of the mine is warranted.

The mine is situated on the east bank of the Mourne River at Milltown about

I km upstream from Strabane Bridge [Irish Grid Reference: H351 965]. Two adits

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have been driven horizontally into the steep valley side, the longest extending for about 15 m. Garena, pyrite and a little chalcopyrite occur in quartz-filled shear zones a few centimetres wide, striking 325? and dipping north-west at 50?. The wall rock lis Dal radian quartzo-feldspathic schist dipping 2?-3? N.E. Limestones and calcareous green shists which crop out close by (Fig. 1) are probably equivalent to the rocks of the

Dungiven Limestone Group of Hartley (1938).

f/ .. ^ ^gfes!S?S>;jK:-5r Dungiven I_I ? t . . Jt j&^my -V?8?^g^^-r^2^:jga^ jy K^M Port Dalradian

5-+SStrabane ft^^ * / \x [ : i | Dungiven Limestone 3

I-SSfiE jk i t ^>>:j Middle Oatradian

f-T-'r.P tJ S -?>. jf^j/ &Jb\ Lead working

?**#!^i, \ s\^#?C,fflM&/M*?* Lead oceurrenc.

-. ̂ ---.-.-----^-- \ ^>>/^ MXMnmt&ii*&>\_I 10 Kilometres

Fig. 1. Sketch map to show relationship of galena occurrences to Dalradian stratigraphy.

Simplified from Hartley (1938) and Pitcher and Berger (1972).

No evidence has been obtained as to the exact date of working of the mine,

although it appears to be of some antiquity. The mine is situated on land formerly

part of the Abercorn Estate. In a letter dated 10 September 1758 the estate's agent, Nathaniel Nisbitt, writes to the Earl of Abercorn in London:

"Neither the colliers nor I could find any vein in the manor of Magaveiin but

what consisted of different sorts of common stone and clay; they were at what is

called the lead mine near Strabane and took some pieces of it but professes no skill of

anything but coals; ..."

This letter suggests that working had ceased at the mine at the time of writing.

(The "colliers*' referred to were evidently engaged in & search for coal in the district.)

A "lead vein" is marked at the site of the mine on the First Valuation Map

published in 1833. There is no mention of the mine, however, either in the official

valuation records even for the first valuation of 1833, or in the valuation field book.

No further reference to the mine since that time can be found. The Strabane

area (Sheet 17) was one of the few mapped only on the one-inch scale during the primary

geological survey of the last century (Kinahan et al 1889). Hence the mine could easily

have been overlooked. It is not located, however, on the six-inch field map made in 1907

by S. B. Wilkinson. Neither of the main writers on the economic geology of Ireland

makes any mention of the mine (Kinahan 1889, Cole 1922). Galena is of fairly frequent occurrence in the Sperrin Mountains (Bazley 1969,

J. J. Hartley, manuscript 6-inch maps) and two other small mines were worked in

addition to the one at Strabane. One at Teebane, near Greencastle, is mentioned by Nolan (1884, p. 24-5); the other at Glenlark was located recently by Dr C. T. Morley

(personal communication to Dr A. Brandon). It is said to have been' an adit driven at

160? which collapsed after 13 m. Most of the known galena occurrences fall into two

groups, of which the more northerly shows a close relation to the Dungiven Limestone

Group with its associated basic igneous rocks, green-schists and black shales. The group to the south falls mainly within the outcrop of the Mullaghcarn Schists of Hartley (1938).

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43

The restriction of galena to certain horizons in the Dalradian succession may prove a

useful guide to any prospecting work carried out in the area. Details of all the galena occurrences shown in Fig. 1 are available for

examination at the Geological Survey of Northern Ireland, and a 1:253 440 provisional Mineral Deposits Map has been prepared for the whole of Northern Ireland.

The writer is indebted to Mr. W. H. Crawford, Public Record Office of Northern Ireland, for the discovery of the references to the Strabane Lead Mine and to Mr J. W. Arthurs for locating two of the galena occurrences. Miss M. Smyth drew the text figure. This paper is published with the permission of the Director of Geological Survey in Northern Ireland.

Geological Survey of Northern Ireland, 20 College Gardens, Belfast, BT9 6BS.

REFERENCES Bazley, R. A. (1969). A discovery of galena near Feeny, Co. Londonderry. Ir. Nat. J.,

16; 233-4.

Cole, G. A. J. (1922). Memoir and map of localities of minerals of economic importance and

metalliferous mines in Ireland. Mem. Geol. Surv. Ireland.

Hartley, J. J. (1938). The Dalradian rocks of the Sperrin Mountains and adjacent areas in

Northern Ireland. Proc. R. Ir. Acad., 44B: 141-171.

Kinahan, G. H. (1899). Economic geology of Ireland. /. R. Geol. Soc. Ir. 8: 514 pp. 514 pp .

-, Wilkinson, S. B. Nolan, J. and Egan, F. W. (1889). Explanatory memoir to accom

pany Sheet 17 and S. E. portion of Sheet 11, Mem. Geol. Surv. Ireland.

Nolan, J. (1884). Explanatory memoir to accompany Sheet 26. Mem. Geol. Surv. Ireland.

Pitcher, W. S. and Berger, A. R. (1972). The Geology of Donegal. Wiley-Interscience, New

York, 435 pp.

A FURTHER STUDY OF THE FOOD OF BARN OWLS, TYTO ALBA (SCOPOLI) AT A ROOST IN CO. GALWAY

F. L- Clark

The previous study at this roost (Fairley and Clark, 1972) was based on monthly collections of regurgitated pellets over a period of one year. At the end of this study in

August, 1972, it was thought that Menlough Castle (Grid reference M 2828) was to be

redeveloped as an hotel* as there was no immediate evidence of redevelopment, it was

decided to continue further regular collections of pellets.

Methods

Pellets were cleared on seven occasions, usually between the twenty-fifth and

twenty-eighth of each month. Unfortunately, the January collection was unavoidably missed, therefore the pellets for January were collected in the February sample. The

pellets were then dried in an oven, broken up, and the required bones removed. The numbers of rodents and birds were assessed, using Fairley's criteria (1967). The total

frogs, Rana temporaria (L.) were estimated from the maximum number of left or right halves of the pelvic girdle.

The owls were observed on three occasions in the study period.

Results

The roost at Menlough Castle is situated in a fireplace some 5 m from the ground. The owls emerging from this, all pellets were collected on the ground in the area beneath this fireplace. In October, one owl was at the roost and this remained unchanged until March, when another owl joined the former, presumably the original owl had taken a mate, as was the case at this time the previous year. For reasons unknown, the owls left

the roost sometime in April, and although the roost was visited each month, no pellets were found until September, when six fresh pellets were found beneath the same

fireplace that had previously been used. As the author left Galway in this month, no observations were made, although more pellets were collected at the end of September.

The numbers of the various major prey are given in the table. As prey species are by no means the same weight, conversion factors were used, to create a more realistic

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