3IO 



NA TURE 



{Jan. 28, 1886 



tion, capable of giving resistances from 24 to 62,000 ohms. — M. 

 Boiirbouze, new models of hygrometers. In these instruments, 

 which are modifications of the dew-point hygrometer, the forma- 

 tion of the first film of dew is observed by causing the deposit to 

 be made on thin glasses which form the sides of the etlier- 

 -chamber, when, on viewing a candle or other luminous point 

 through the glass, coloured halos are visible. 



SOCIETIES AND ACADEMIES - 

 London 



Royal Society, December 10, 1885. — "On the Relation 

 of the Reptiliferous Sandstone of Elgin to the Upper Old Red 

 Sandstone." By Prof John W. Judd, F.R.S., Sec.G.S. 



The question of the geological age of the yellow sandstones 

 of the district lying to the north of the city of Elgin has been, 

 as is well known, the subject of very animated discussions among 

 geologists. Some have even gone so far as to assert that the 

 evidence on the question, which has been adduced by strati- 

 graphists, is absolutely incapable of reconciliation with that 

 relied upon by palaeontoloa;ists. 



After detailing the successive discoveries of fossils in the^e 

 beds from 1844. to 1877, in which latter year Prof Huxley pub- 

 lished his well-known monograph on StagonoL'pis, the author 

 proceeds : — 



In the year 1S84 I saw in the Elgin iVIuseum the cast of a 

 skeleton which had recently been obtained from the new quarry 

 near Elgin, to be more particularly referred to in the sequel. 

 This fossil appeared to me to be so different from all the remains 

 hitherto found in the formation, that I obtained an impression of 

 it and submitted it to Prof. Huxley, who recognised in it certain 

 characters distinctive of the Dinosauria. From the same quarry 

 a skeleton apparently belonging to another lizard, distinct both 

 from Tderpeton and HvperodapeJon, with portions of the 

 skeleton of the last-named genus, were also obtained. 

 ■■■Returning to Elgin in the autumn of the present year, I was 

 told by my friend Dr. Gordon that another reptilian specimen, 

 including the skull and some other parts of the skeleton, had 

 been found in the same quarry. On examining this specimen I 

 at once saw that it exhibited the characteristic features of 

 Dicynodon , and my opinion on the subject was confirmed by my 

 friend Dr. Traquair, F. R.S., of Edinburgh, who, at my request, 

 proceeded to examine the specimen. A second example of the 

 same genus has since been discovered, and I trust that ere long 

 a full account of this interesting form will be given by Dr. 

 Traquair. 



In addition to the=e fjcts, I may add that casts of teeth, un- 

 distinguishable from those of Ceratodi(s, were some time ago 

 obtained from the Spynie quarries. 



The present state of the palseontological evidence concerning 

 the age of the beds then is as follows. The strata have yielded 

 the remains of no less than four orders of reptiles, all of them 

 belonging to forms very different from any which have been found 

 in Palaeozoic rocks. The Lacertilia are represented by Tder- 

 piton, Hyperodapedon, and an undescribed form ; Crocodilia by 

 Stagonolepis ; Dinosauria by an undescribed skeleton, and possibly 

 by Dasygnathus ; and Dicynodontia by two individuals of the 

 type genus. In addition to these we have a great number of 

 footprints differing so greatly in form or size that they must 

 probably have been made by creatures of very different proportions 

 and organisation. 



It will be seen from this summary that the pakeontological 

 evidence in favour of the Triassic .age of the Elgin sandstones is 

 now absolutely overwhelming. Besides the remains of Hypfro- 

 dapedoit and Dicynodon, genera which appear to be confined to 

 Triassic strata, in districts so widely separated as South Africa, 

 India, the Ural Mountains, and the British Islands, we have 

 Stagonolepis, a crocodile with Mesozoic affinities, the highly organ- 

 ised lizard Tcleypeton, and Dinosaurs ; the last-mentioned having 

 never been found in any rocks older than Trias. Ccmtodtis, too, 

 has usually been regarded as having commenced in the Trias, 

 though it must be admitted that difficulty may exist in separating 

 the cast found at Spynie from Ctenodiis, which occurs in the 

 Carboniferous, or Diplerus, which occurs in the Devonian. 



Let us now inquire what is the nature of the stratigraphical 

 evidence which has been regarded as opposed to the palfeonto- 

 logical arguments in favour of the Triassic age of this formation. 

 At the outset it is necessary to bear in mind two ver)' important 



circumstances. First. The exposures of the Reptiliferous Sand- 

 stone and of the Upper Old Red in the district are more or less 

 isolated, the greater part of the country being thickly covered by 

 drift and other superficial deposits. Secondly. The whole of the 

 rocks in the district exhibit evidence of having undeigone great 

 disturbance ; this is shown by their steep inclinations, and by the 

 foldings and fractures which can often be recognised in the 

 quarries opened in them. 



The Reptiliferous Sandstone makes its appearance at the sur- 

 face in two parallel ridges, Hanging from north-east to south- 

 west for a distance of about nine miles. The most northerly of 

 these ridges extends from Brandenburgh to Burghead. Although 

 the rocks are well exhibited both in sea-cliffs and in reefs on the 

 shore, the only fossils obtained from them are the fo')tprints of 

 the Cummingston and Hopeman quarries, near the south-western 

 extremity of the ridge, and the remains of Sta^onolepis, Tehr- 

 peton, and liyptrodnpcdon, found in a single bed at Lossiemouth, 

 at its north-eastern end. A tract of about three miles wide, 

 thickly covered by superficial deposits, completely isolates the 

 northern or coast ridge from the southern one, which is known 

 as the Quarrywood ridge. In this Quarrywood ridge the Rep- 

 tiliferous Sandstone is only found along its northern face for a 

 distance of about three miles. The southern slope is composed 

 of the ordinary rocks of the Upper Old Red Sandstone, con- 

 taining Holoptychius nobilissimus, Ag. , with species of Glypto- 

 pomus and Plerkhthys, There is no evidence of the occurrence 

 of Triassic strata, either along the southern slopes of the Quariy- 

 wood ridge or in the district lying still further south about the 

 city of Elgin. The localities in which the s.andstone containing 

 reptiles has been found along the northern slope of the Quany- 

 wood ridge are as follows : — At Spynie, which may be regarded 

 as a north-eastern prolongation of the Quarrywood ridge, the 

 deep quarries have yielded Tderpeton, Hyperodapedon, and 

 Ceratodits. At Findrassie Wood, a mile and a half further to 

 the south-west, a quarry, now abandoned, has yielded Slago- 

 •tolepis and Dasyanathus. Lastly, the quan-y near the top of 

 the ridge, above New Spynie Church, .and a mile and a half 

 still further to the south-west than Findr.assie, has yielded 

 Hyperodapedon and another lizard with a Dinosaur and a 

 Dicynodont. 



In both the c-ast ridge and the Quariywood ridge, as was well 

 pointed out by Dr. Gordon, the Reptiliferous Sandstone is seen 

 to be covered by a very peculiar and easily-recognisable deposit, 

 known as the " Cherty rock of .Stotfield." It has been fre- 

 quently suggested that the preservation of these two sandstone 

 ridges, and thus of the whole peninsula between Burghead Bay 

 and Spey Bay, was in all probability due to the presence of this 

 remarkable rock, which offers such resistance to the ordinary 

 agents of denudation.' The rock consists of a more or less 

 intimate admixture of siliceous and calcareous materials, in- 

 cluding also crystallised patches of g.alena, blende, and pyrites ; 

 it has yielded no trace of organic remains. Sir Roderick 

 Murchison compared the "Cherty rock of Stot field" with the 

 Cornstones of the Old Red series, with which, however, they 

 have but little in common ; and some confusion appears to have 

 arisen from bands of true Cornstone, which occur in Upper Old 

 Red .Sandstone to the south of Elgin, with the Cherty rock of 

 the Trias. 



Prof Harkness in 1864 was able to show that the positions in 

 which the Cherty rock and the Reptiliferous Sandstone occur in 

 the neighbourhood of Elgin are such as can only be explained 

 by the existence of great faults. At a later date I showed how 

 numerous are the indications of disturbance in the district — 

 evidence of tilting of the beds, of actual contortion, and of 

 fracture occurring in many of the quarries. On the north of the 

 coast-ridge I have shown that beds of Inferior Oolite are found 

 faulted against the Trias at Stotfield,- and pr^ibably also at 

 Burghead. In the gre.at " Scars," or reefs, which lie off this 

 coast red sandstones are seen, and I have been assured that 

 scales of Holoptychius occur in them. The presence of these 

 great lines of dislocation is unquestionable, and in the paper 

 referred to I have endeavoured by means of dotted lines to 

 indicate the approximate position of some of them. It must be 

 remembered, however, that in a country so deeply covered by 

 drift as Northern Morayshire, the working out of the relations of 

 the rock-masses by tracing their outcrops at the surface is an 

 almost hopeless task. 



As throwing an entirely new light on the age and relations of 



■ Quart. Journ. Geol. Sec. vol, xx, (1864), p, 424. 

 = IHii. vol. .XXIX. (1S73), p. 128, &c. 



