26 



SCIENCE-GOSSIP. 



GEOLOGY 



Geology at Belfast. — We have to record a 

 remarkable week of geological studies conducted 

 by Professor G. A. J. Cole, M.R.I. A., F.G.S., 

 of the Royal College of Science for Ireland, 

 which terminated at the end of March. A 

 paper on the structural details of the Antrim 

 rhyolites, read at the microscopical meeting of the 

 Belfast Naturalists' Field Club, commenced the 

 course, lantern-slides showing the microscopic 

 character of local lavas, varied by others of 

 rhyolitic areas in other parts of Great Britain. 

 The scheme included six excursions for the 

 study of geology in the field, three hours each 

 evening being devoted to a class on petrography, 

 necessarily limited to a dozen students, resem- 

 bling a "special course" at the Dublin College 

 of Science. 



The first field excursion was to Squire's Hill, 

 where the series of Cretaceous quarries were visited, 

 Professor Cole pointing out and explaining the 

 methods in which the many dykes had intruded 

 through the sedimentary rocks ; also drawing the 

 attention of his students to the difference between 

 the Irish Cretaceous series and that of England, 

 showing the persistence of upper chalk fossils such 

 as Bekmnitella mucronata through the limestone to the 

 base of the glauconitic chalk, whilst the general 

 palseontological characters suggested that the 

 chalk must represent the Senonian, the greensand 

 the Turonian, and the somewhat barren lower beds 

 (which, however, furnished Pecten qxiinquecostatus 

 and other characteristic fossils) belonged to the 

 Cenomanian series. A visit to the basaltic quarry 

 led the party across Carr's Glen to the Cave Hill 

 quarry, with its great dyke showing horizontal 

 columns, which traverses the chalk and the over- 

 lying basalt. 



The second excursion made an early start for 

 Stewartstown, involving a walk of ten miles 

 through fine rolling country, passing Tullahoge, 

 and on to Tullyconnell for the Permian strata that 

 are so rare in Ireland. The survey memoir 

 describes a section on the roadside, but this is no 

 longer visible, a block below the road, nine or ten 

 feet long, and a poor exposure in an adjacent cottage 

 garden, being all that now remains. The rock is very 

 fossiliferous. The Castle Farm quarries at 

 Stewartstown furnished fossils from the Carboni- 

 ferous Limestone, some pits in the lower coal 

 measures being passed on the return drive to 

 Dungannon. 



On Friday the party walked from Dundonald, 

 among the interesting partially-cemented gravels^ 

 full of travelled pebbles, by the old road to 

 Scrabo, a halt being made by the way to visit 

 and photograph the Kemp stone. Professor 

 Cole utilised the pause for lunch on the slope of 

 Scrabo, whence a glorious prospect was obtained 

 of Strangford Lough and the distant coast of 

 Antrim, by explaining how this outlier of Triassic 

 sandstone was formed by the slow sinking of 

 8 hallow-water lakes, a parallel being found in the 



present condition of the Great Salt Lake in America. 

 Saturday was devoted to the rhyolitic area, 

 which has been specially studied by Professor 

 Cole for some years, and magnificent weather 

 favoured the party as they drove from Doagh to 

 Sandy Braes, and proceeded to visit the innumer- 

 able exposures that are found over the charming 

 heathery moorland, where the glassy lavas of the 

 old volcano are displayed in marvellous variety. 

 The causes of this variety were fully explained by 

 Professor Cole, who said that hitherto geologists 

 had sought for acid lavas from Hungary or Lipari, 

 and only a few realised the stores that lay decom- 

 posing on the hilltop around Tardree. Lunch at 

 the southern quarry on Tardree was followed by 

 a walk across Carnearny Brae into Antrim, visit- 

 ing a hole where the rock showed singularl}' large 

 felspar crystals found by Mr. A. G. Wilson, and 

 an interesting boss of glassy rhyolite, with both 

 spherulitic and perlitic structure, discovered by 

 Professor Cole some time ago. 



The geologists made a fresh start on March 23rd, 

 the place selected being Barney's Point, near 

 Magheramourne, where abundant Lower Lias fossils 

 were obtained. Fragments of Rhaetic rock led 

 Professor Cole to point out that these Liassic beds 

 had probably slipped forward over the lower 

 strata. Crossing the backbone of Islandmagee, 

 the party inspected the fine basaltic cliffs at the 

 Gobbins, longing for the access to their face 

 which will be given, should the walk projected by 

 the Northern Counties Railway Company ever 

 be constructed. The return to the ferry showed 

 the opposite hills blue with approaching rain. 

 Yet splendid weather favoured the final excursion 

 on the following day, which included a visit to 

 the mountain range of Mourne. The dykes south of 

 Newcastle, which traverse the uptilted Ordovician 

 strata, frequently traversed themselves by later 

 dykes, were visited, Professor Cole demonstrating 

 their age by explaining that the Mourne granite 

 which cut through them was of the same age as the 

 rhyolites of Antrim. 



The party subsequently ascended by the Bloody 

 Bridge and Glen Fofany, when another address 

 taught the students that many so-called moraines 

 were in reality great detrital fans of mountain 

 debris. Mr. LaTouche (Geol. Survey of India), who 

 was with the party throughout the week, described 

 the making of such a fan in the Himalayas in a 

 few hours, when a mountain torrent swept every- 

 thing before it, spreading a mass of mud and stones 

 over the lower ground, the river at first flo\ving 

 over its handiwork, and subsequently cutting 

 through it. An ascent of Thomas Mountain, to 

 see the fragment of the Ordovician strata that 

 remains — a relic of the great sedimentary arch 

 under which the molten granite gathered — was 

 followed by a descent through the grounds of 

 Donard Lodge. 



The value of such a week caimot be over- 

 estimated ; and any field club that has such a 

 chance to offer to its members well deserves 

 its name. This is the third time that the Belfast 

 Club has been fortunate in securing instruc- 

 tions from Professor Cole, and the importance 

 of such continuity is manifest. The presence 

 of members of other clubs recalls pleasantly 

 the recenty-founded Irish Field Club Union, with 

 its useful plan of admitting members of other 

 clubs who may be temporarily in a strange place 

 to the honorary membership of the club of the 

 locality. 



