1839.] 



THE CIVIL ENGINEER AND ARCHITECT'S JOURNAL. 



229 



mon to both. The Canada fossils, howevef, S9 far as tliej' have liithcrto been 

 examined, do not agree as a whole, with the testacea now inhabiting the Gulf 

 of St. Lawrence : many of the species ranging, in a living state, from the Gulf 

 to the border of the North I'olar Circle, or are now only known in high 

 northern latitudes, as in the seas of Greenland, Iceland, and Norway, or agree 

 with shells found in the newer Pliocene of Scotland and Sweden. On the 

 contrary, many of the shells most conspicuous in the Gulf of St. Lawrence, 

 have not been found in a fossil state. As the climate of Canada is now exces- 

 si?e, it is natural that many northern and arctic shells should exist in the Gulf 

 of .St. Lawrence, without any mixture of tropical forms; it is very probable, 

 also, that in the period immediately antecedent to the present, the climate of 

 Canada was even more excessive than it is now, and that the shells n'sembled 

 still more closely that small assemblage existing in high nortliern latitudes. It 

 is likewise evident, from the manner in which the large fragments of rock are 

 interspersed through the shelly stiata near Quebec, ihat while these deposits 

 were forming, blocks of ice were annually transported as at present. Among 

 the fossil shells near Quebec, not one has yet been foimd which can be affirmed 

 to be extinct. They relate, therefore, to an extremely modern [rcriod, and, 

 though the climate may then have been more excessive than at present, a more 

 equable one may have preceded, and the alterations may have been connected 

 with the geographical ch.tnges which upheaved the shelly deposits of Canada 

 200 feet above their former level. 



3. -In Eximvt of a Letter from Herr F. A. Ro':mci- to Dr. Fitton, dated 

 Hildrsham, March 20. 



The Wealden formation, including the Purbeck stone, is very extensively 

 developed in the North of Germany, and is overlaid by a great argillaceous 

 deposit, containing marine shells, similar both to the oolitic and the creta- 

 ceous systems. Of the fossils found in the Wealden of England, almost every 

 species occurs in Germany, including even the minute Ci/pris tHhcriuUitu, 

 C. granulosa, and C. Valdciisis. Last autumn, Hcrr Roemcr discovered the 

 Wealden, with its characteristic shells, near Botlingen, in the High Alps. He 

 possesses also the Li-pidotus Mujitelli, of the English Wealden, from Saxony. 

 The Portland sand occurs in the North of Germany, but the Portland stone 

 and the Kimmeridge clay are so intimately connected by their fossils, that the 

 intermediate sandy beds cannot be considered as a separate deposit. The 

 chalk with flints occurs possibly in the Hartz. The green-sand series is exten- 

 sively developed, the Flammenmergel of Hausmann being the upper green-sand 

 of England, and the quader-sandstoin the lower. Hcrr Roemer believes that 

 the gault also exists in Northern Germany. 



4. Clasnijicativn of ttir Older Rochs of DcLonshire and Cornwall, by Prof. 

 Sedgwick and Mr. Mubciiison. 



In a former communication to the Society the authors explained 

 their general views respecting the older rocks of Devonshire and 

 Cornwall, but having recently been induced, on zoological evidence, not 

 then obtained, to make a change in the lower part of their classification, they 

 give in this paper their reasons for doing so. With respect, however, to the 

 geological age of the culmiferous strata occupying the greater portion of 

 Devonshire, they adhere to their first opinion, and consider them the equiva- 

 lents of the true coal measures of other parts of England. In the grouping, 

 succession and lithological characters of the great series of beds underlying 

 the culmiferous strata, they likewise make no alteration, and used, in reading 

 the paper, the same section which they exhibited to the British Association, 

 at Bristol, in 1835, when they first explained the true position of the culm 

 deposit. On their first examination of Devonshire and Cornwall, they were 

 induced to consider the great slaty and sandstone districts forming Exmoor 

 and tiiG Quantocks on the north, and a large portion of southern Devon and 

 the whole of Cornwall, as the lower part of the .Silurian system and the upper 

 part of the Camljrian, having been misled by the slaty character of the rocks, 

 and its supposed proof of geological antiquity. A recent examination, how- 

 ever, of the fossils collected by the authors, or kindly sent to them for the pur- 

 pose by the Rev. R. Hcnnah and the Rev. D. Williams, has proved that the 

 strata immediately subjacent to the culm series (shown on a former occasion to 

 contain true coal-measure plants). enclose fossils resembling those in the lower 

 carboniferous strata of the north of England ; that the great mass of iiiterme- 

 diate beds aie characleriied by peculiar fossils ; and that the lowest strata 

 contain some which partake of the same type, and others which belong to the 

 upper Silurian formations- On these grounds, therefore, the authors have 

 been induced to remove the slates and older sandstones of Devon and Corn- 

 wall from the position they first assigned to them, and to place them on the 

 parallel of the old red sandstone, the intermediate series of strata between the 

 carboniferous and Silurian systems. Had, however, the whole of the evidence 

 derived from organic remains been before the authors in I8.'i(), the geological 

 age of the strata could not then have been determined, as the fossils of the 

 Silurian system, one of the terms of comparison, had not been fully ascer- 

 tained. In the gradual passage of the strata from one group to another, and 

 in the recurrence of the same groups north and south of the great culmiferous 

 or carboniferous series of central Devon, there is the most decided siratigra 

 phical evidence of the whole of the country; belonging to one geological epoch. 

 The marked difference between tlie slates of Devonshire and Cornwall, and 

 the sandstones of Herefordshire with the adjacent counties, hitherto considered 

 types of the old red system, the authors showed can he no valid objection to 

 the proposed dassilication, as lithological characters have been long proved to 

 be of little or no importance in connecting deposits, at even very limiled 

 distances. The absence of the true carboniferous limestone was also shown to 

 be no argument against the arrangement of the authors, as on the western ex- 

 trenrily of Pembrokeshir-c, that formation is entirely wanting, and the 

 culnr or coal-mcasuies rest immediately otr older rocks. Lastly, the 

 authors proposed, in consequence of the strata in Devonshire yielding the belt 



zoological type, to substitute the term Devonian system for old red, and they 

 expi-essed a hope that the determination of these fossils would assist in filliirg 

 up the sequence of geological formations, and enable observers to discover, in 

 other parts of the world, a series of deposits hitherto supposed almost peculiar 

 to the British isles. The authors acknowledged the assistance they have 

 received from Mr. James De Carlo, Sowerby ; and that Mr. Lonsdale first 

 suggested that the limestones of .South Devon would prove to be of the age of 

 the old red sarrdstonc. The paper was illustrated by the large index map of 

 the Ordnance Survey, coloured by the authors, and it exhibited the r-angc of 

 the scver-al systems through North and South Wales, the border counties of 

 England — Devonshire and Cornwall. 



5. A Notice OH tlic ijciicral relation o/ the variOKS Bands of Slate, Limt- 

 stone, and Sanihtone in South Vcpon, by Mr. li. A. C. Aisten. 



Commencing with the oldest deposits east of the Teign. there appear — 1, 

 Slates ; -2, A barrd of black limestone containing corals and shells, and some- 

 times thin seams of anthracite — it ranges from Staple Hill through Bicking- 

 ton, Ashburton, Buckfastleigh, and Dean; 3, Fine-grained schistose shale 

 and slates; 4, The limestones of Plymouth, Dunwell, Shilstone, Ugborough, 

 North Huish, Little Hempston, txc, — they are associated with scistose r-ocks; 

 5, A great arenaceous deposit, often coarse and resembling old red sandstone : 

 Eome'.irncs conglomeritic, when it resembles the new red ; it ranges from 

 Plymouth Sound and Uigbury Bay, across the central part of South Devon, 

 by Modhury and Blaekdown, cutting the Dart below Totness, and ranging 

 thence through Marldon, Cockington, and Bartorr ; in some places it contains 

 thin bands of limestone ; 6, The limestones of Torbay. Mr. Austen says the 

 carbonaceous rocks of central Devon form no part of this series, but rest upon 

 it unconformably. 



Lastly. A Notice, by Mr. Miller, of Cromarty, On the exact p'lsiliun in 

 the old red sa/idstone, of the bed containing fosad Jishes and exposed in the cliffs 

 of the Moray Fritli. It is overlaid by a yellow sandstoirc and rests upon a 

 deposit of a red sandstone, chocolate coloured conglomerate, and impure linre- 

 stonc. The base of the whole is stated to be granatic gneiss. 



May 8. — Tlie Rev. Dr. Buckhmd, I'rcsident, in the chair. Three com- 

 nnuiications were read :— 



1. On Casts or Impressions of Vermiform Bodies on thin Flaystones, 

 helunc/iiK/ to tiic Carboniferous series near Ilallwliistle, in Nurthumberhind, by 

 Mr. G. C. Ati^inson. ' The bed of sandstone is about eighteen feel thick, 

 aird the .surface of the layers of wliich it is composed, present, in almost 

 every instance, tortuous iirrpre.ssion.s, or casts marked by a longitudinal 

 furrow, and occasional transverse closely set lines. 



2. On the London and Flaslie Clays of the Isle of Wight, by Mr. 

 Bo^vERB.v^'K. The object of this comniunication was, to show that there 

 is no zoological distinction between the two clays, the author haviirg found 

 that many of the same species of testacea range through the wliolc series of 

 beds in White Clifl' and Alum Bays. 



3. On the rclatire Ayes of l/ic Tertiary Deposits commonly called Crag, in 

 Norfolk and SnJj'oll<,by Mr. Lvicll. Three poiirts of great importance 

 relative to the Crag of Norfolk and Suflblk arc discussed in this luemoir. 

 1st. The direct superposition of the red to the coralline crag, as pointed out 

 by Mr. Charlesworth in 18.3.5. '2ndl3'. Whether mammalia are really im- 

 bedded in midisturbed marine strata of the crag of Norfolk. 3dly. 

 Whether the proportion of recerrt shells, as compared to the extinct, is 

 decidedly larger in the crag of Norfolk, so as to indicate a posteriority iu 

 age relatively to the Suffolk crag. With regard to the first poiirt, Mr. 

 LycU states, that the red crag is clearly superimposed on the coralline at 

 Kamsholt, Tattingstone, and Sudburn, resting at the two former localities 

 on denuded beds of the lower deposit. He ascertained, also, by the assist- 

 ance of Mr. W. Colchester, that at Sutton, near Woodbridgc. the red crag 

 abuts against a vertical face or clifl' of the coralline, and likewise overlies 

 it. In this instance, the sand which composes the older bed, or coralline 

 crag, had evidently acquired a certain consistency at the bottom of the 

 sea before the rr'd crag was deposited, for it has been perforated by nume- 

 rous pholadcs, the tortuous holes of which descend six or eight feet below 

 the top of the bed, and still contain the shells of the pholas, while the 

 remamder of the cylindrical hollows has been filled with the sand of the 

 superiircumbent stratum. With regard to the second point, the occurrence 

 of mammalia in undistuvlicd beds of marine crag in Norfolk, Mr. Lyell 

 slates, that he had ascertained, by air examination of tins crag near South- 

 wold and Norwich, that it is not purely marine, but contains everywhere 

 an intermixture of land, freshwater, and seashells, with bones of mammalia 

 and fishes. In this deposit near Southwold, Captain Alexander, who 

 accompanied the author, found, some time since, the tooth of a horse, 

 within a large specimen of Ft(sus striatus, and he uiforined Mr. LycU that 

 bones of miunmalia are frequently associated in the same beds with those 

 of fishes, marine shells, and Crustacea. In the neighbourhood of Norwich, 

 this deposit forms )iatches of variable thickness, resting on chalk and 

 rovcredby gravel. It is well exposed at Bramcrton, WhilUughain, Thorpe, 

 and Postwick, and presents beds of sand, loam, and gravel, containirrg a 

 mixture of marine, terrestrial, and fluviatilc testacea, ichthyolitcs, and 

 bones of rnainmalia. The chalk on which it rests was shown, by the late 

 ISlr. Woodward, {» have been drilled by marhic animals; and (he Kcv. Mr. 

 Clowes, I'f Yarnrouth, prcscirlcd .Mr. Lyell with a specimen of chalk con- 

 fainiiip a I'liolas erispatus in n pcrforatiini several inches deep. TJial this 

 pcirtioir of the crag was slowly accumulated, is evident from Captain 

 Alexander liaviirg fouird, at Branicrloir, the tusk of an elephant, with marry 

 supcrUe ou its siui'iice; and, from this fact, JMr. Lyell infers that tire bones 



