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TIt E

QUARTERLY JOURNAL

OF

THE GEOLOGICAL SOCIETY OF LONDON.

PROCEEDINGS

OF

THE GEOLOGICAL SOCIETY.

JUNE 2, 1852. W. H. Gomonde, Esq., J. H. Blofeld, Esq., and Dr. Finlay, R.N., were elected Fellows. The following communications were read :-- 1. On the GEOLOGY of the BAHAMAS, and on CORAL-FORMATIONS generally. By Capt. R, J. NELSON, R.E. [Communicated by Sir C. Lyell, V.P.G.S.]

2. On some FossIL PLANTS from the LOWER TRIAS of WARWICK- SHINE. By Dr. G. LLOYD, F.G.S. [This paper was withdrawn by the Author, with the permission of the Council.]

JUNE 16, 1852. M. J. Scobie, Esq., was elected a Fellow. The following communications were read :-- I. On a prolrudedmass of UPPER LUDLOW ROCK at FARK in . By H.E. STRICKLAND,Esq., F.R.S., F.G.S. So laboriously minute have been the researches of the Officers of the Geological Survey of Great Britain, that it is only where some VOL. VIII.~PART I. 2 C Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 14, 2016

382 PROCEEDINGSOF THE GEOLOGICAL SOCIETY. [June 16, fresh sections have been subsequently exposed by the operations of nature or of man that any material additions or corrections of that Survey can be looked for. A case of the kind has lately occurred in Herefordshire, revealing a small protrusion of Silurian rocks in the midst of the Old Red Sandstone, and accompanied by circumstances of some geological interest. A quarry having been opened near the base of the Old Red Sand- stone, a few hundred yards west of Hagley House, near Lugwardine, and a deep drain having been cut from the quarry towards the S.E., the junction-beds of the Old Red Sandstone and of the Upper Lud- low Rock were unexpectedly exposed. This circumstance attracted the notice of M. J. Seobie, Esq., of , to whom I am in- debted for having my attention drawn to the spot, and for many in- teresting organic remains and geological details which his residence in the vicinity enabled him to collect. I must also express my obliga- tions, and those of the other geological friends who accompanied me, to Robert Biddulph Phillipps, Esq., the owner of the land, who kindly caused part of the quarry to be re-opened for our inspection. The area of Silurian rocks here exposed on the surface does not exceed three or four acres ; it consists of yellowish sandstones refer- able to the "Downton Sandstones" of Sir Roderiek Murchison, resting on grey micaceous Upper Ludlow schists, and dipping on all sides beneath the sandstones and marls of the Old Red Series. They seem to form a portion of a very flattened dome, and the quarry, which extends about seventy yards from N.W. to S.E., cuts through this dome on its south-western slope. Such at least is the conclusion drawn from the dip of the beds, which at the north end of the quarry is about 10 ~ N.W. byW. ; atthe middle of the quarry, 5~ ; about twenty yards further S., 8 ~ W.S.W. ; and at the southern extremity, 7 ~ S.S.W. The following section is here exposed in de- scending order, as far as the irregularities of the stratification permit them to be measured. ft. in. Old Red Sandstone..., 1. Red marls and clays, containing bands of whitish sandstone, not calcareous, about ...... 12 0 2. Hard brownish sandstone...... 2 0 3. Flaggy, slightly micaceous, brown sandstone ... 2 0 4. Highly micaceous,thin-bedded,brown sandstone 2 0 5. Band of clay and rubble, about ...... 0 6 Downton Sandstones.. 6. Micaceous yellowish sandstone, with traces of carbonized plants ...... 2 0 7. Clay and rubble...... 0 6 8. Micaceousyellowish sandstone, with numerous fragments of carbonized plants ...... 4 0 [ 9. Bones, teeth, and scales of fish, about ...... 0 1 Upper Ludlow Rocks. ~ 10. Grey micaceous shale, effervescing with acid, L full of fossils, about ...... 4 0 29 1 The vegetable remains in the beds Nos. 6 and 8 are interesting from their extreme antiquity, but in general present no traces ~f their organic structure. They are merely rounded and water-worn frag- ments converted into a coaly mass, which cracks in drying. When Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 14, 2016

1852.] STRICKLAND~UPPER LUDLOW ROCK AT HAG]bEY PARK. 383 ignited, these fragments burn like anthracite, without smoke or flame, and remain ignited until they are reduced to a light white ash. The occurrence of vegetable remains in the corresponding beds at Down- ton Castle is noticed by Sir R. Murchison * and near Stoke Edith, and in the May Hill district by Prof. Phillips J'. The bed No. 9 is interesting as being unquestionably the repre- sentative of the "Ludh)w Bone Bed," described by Sir R. Murchi- son~:. His description of this deposit near Ludlow, as "a mass of scales, ichthyodorulites, jaws, teeth, and coprolites of fishes, united by a gingerbread-coloured cement," is precisely applicable to the stratum at Hagley. The cement which unites the bones is calcareous and imperfectly crystalline, exhibiting a chatoyant lustre when the eye catches the light reflected from the cleavage-planes. This sin- gular deposit of ichthyic remains occurs as a thin band, in some places no thicker than a wafer, and gradually increasing at other points to about an inch and a half in thickness, as if deposited by eddies in shallow depressions of the sea-bottomw These minute osseous fragments are mostly much water-worn and highly polished by mutual friction. Some of them are black, but the majority are of a yellowish or ferruginous tint. As very few of the bones or teeth are sufficiently perfect to indicate generic or specific characters, we are only able to enumerate the following :- Spines of Onchus Murchisoni, Agass., Sil. Syst. pl. 4. f. 10. Teeth of Thelodus parvidens, Agass., Sil. Syst. pl. 4. s 34-36. Teeth resembling that figured in Sil. Syst. pl. 4. f. 37, but serrated at the margin. Ganoid scales. The only mollnscons remains in the fish-bed are the OrSicula ru- gata, Sil. Syst. pl. 5. L 11, and an Orthis. In some places fi'agments of coaly matter, similar to that in the bed No. 8, are mixed up with these osseous remains. One of these carbonaceous pellets seems to be the seed of some terrestrial plant. It is globular, about a quarter of an inch in diameter, and being broken across exhibits a central cavity, the parietes of which are about one-tenth of an inch thick, and composed of fibres radiating to the external surface H- The bed No. 10 corresponds in character with the uppermost strata of the Ludlow Rocks wherever they are visible in the neigh- bonrhood. It is a fine-grained sandy shale, of a greenish or greyish colour, abounding with small particles of mica, and effervescing with

* Silurian System, p. 197. t Mere. Geol. Survey, vol. ii. pp. 176, 188, 312. :1: Sil. Syst. p. 198. w Precisely the same conditions exist in the case of the well-known bone-bed at the base of the Lias, and are doubtless due to the difference between the specific gravity of the fish-bones and that of the arenaceous grains of the sea-bottom, causing the former to be separated from the latter by the action of the currents. [[ I propose on a future occasion to give a fuller description of these singular bodies, which have since been detected in the same stratum at several other localities. 2C2 Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 14, 2016

384 PROCEEDINGS OF THE GEOLOGICAL SOCIETY. [june ]6,

acids, although not sut~eiently calcareous to deserve the name of a limestone. The following organic remains occur in it at Hagley Quarry :J Cyathophylhm ? Favosites polymorpha, Goldf. sp., Sil. Syst. pl. 15. f. 2. Cophinus dubius, Konig, Sil. Syst. pl. 26. f. 12. Crinoidal stems (pentagonal). Cyathoerinites macrostylus, Phillips, Mere. Geol. Surv. ii. p. 384. Serpulites longissimus, Mureh., Sil. Syst. p1. 5. f. 1. Homalonotus Knightii, K0n/g, Sil. Syst. pl. 7. f. 1, 2. Calymene Blumenbaehii, Brongn., Sil. Syst. pl. 7. f. 5. Rhynchonella semisulcata, Dalm. sp. (Terebratula laeunosa, Sil. Syst. pl. 5. f. ~o). -Wilsoni, Sow. sp., Sil. Syst. pl. 6. f. 7 a. - nueula, Sow. sp., Sil. Syst. pl. 5. f. 20. Orthis orbicularis, Sow., Sil. Syst. pl. 5. f. 16. lunata, Sow., Sil. Syst. pl. 5. f. 15. Strophomena filosa, Sow. sp., Sil. Syst. pl. 13. f. 12. Lepttena sarcinulata, Sehlott. sp. (L. lata, Sil. Syst. pl. 5. f. 13). Orbicula striata, Sow., Sil. Syst. pl. 5. f. 12. rugata, Sow., Sil. Syst. pl. 5. f. 11. Lingula minima, Sow., Sil. Syst. pl. 5. f. 23. Orthonota amygdalina, Sow. sp., Sil. Syst. pl. 5. f. 2. retusa, Sow. sp., Sil. Syst. pl. 5. f. 5. Avicula ampliata, PhilliTs, Mere. Geol. Surv. ii. p1. 23. f. 1. Orthoceras bullatum, Sow., Sil. Syst. pl. 5. f. 29. perelegans, Salter, Mere. Geol. Surv. ii. pl. 13. f. 2. 9 ibex, Sow., Sil. Syst. pl. 5. f. 30.

- gregarium ?, Sow., Sil. Syst. pl. 8. f. 16. Many of these fossils, especially the Orthocerata, are penetrated with sulphuret of iron, which gives them a bright metallic gloss. In addition to the above-mentioned invertebrate forms, an interest- ing portion of a crustacean has been forwarded to me by Mr. M. J. Scobie from the Upper Ludlow shale underlying the bone-bed, of which Mr. Salter has kindly undertaken the description. (See p. 386.) Traces of ichthyic remains, especially the minute teeth of Thelodus ~arvidens, are occasionally found interspersed in the bed No. 10, but never m the same abundance as in No. 9. Having now enumerated the strata of Hagley quarry and their orgamc contents, I must make a few remarks on the geological phve- nomena attending them. It was stated above that the beds here exposed assume the form of a flattened dome. By reference to the map it will be seen that this protruded dome is about half a mile to the N.W. of the well-known dyke of greenstone at Bartestree, which cuts through horizontal strata of Old Red Sandstone, and runs in an E.N.E. direction towards the S. edge of the protruded Silurian mass of Shucknall Hill*. About * See Murchison, Sil. Syst. p. 185 ; and Phillips, Metal Geol. Surv. vol. ii.p. 180. Downloaded from http://jgslegacy.lyellcollection.org/ at University of California-San Diego on July 14, 2016

1852.] STRICKLAND--UPPER LUDLOW ROCK AT HAGLEY PARK. 385 a mile and a half further to the S.E., we come to the elevated region of Woolhope, the axis of which runs for more than ten miles still in a S.E. direction. It appears, therefore, that the ejection of the trap' dyke at Bartestree, together with this protrusion of Silurian rocks at Hagley Park, occur exactly on the axial line of the great elevation of Woolhope. But though this coincidence of position deserves notice, yet the forces which have caused these minor protru- ~ ~1 ~ sionshaveinfactactednearlyatrightanglesThe to the direction indicated. Woolhope ~ ~ I~\l 5 region, though possessing an axis from N.W. ~ ~~] ~ to S.E., is essentially an area, and not a line, of elevation. Its pressures have been distri- ~ buted, not in two opposite directions from au axis, but in every direction from a centre. In "~ I~\ / "~ ~ conformity with this view we find that in its ~~ north-western portion it is cut through by the !'~ ~ "' great Mordiford fault," running N.E. by E. ~ (or nearly at right angles to the major axis), "~. ~ and causing the strata about Dormington and ~ Stoke Edith to assume the same strike, Be- ~ ~ yond the Woolhope area we find the valley of "~ ~ the River Frome, the Bartestree Dyke, and the protruded Silurian mass of ShucknaU HiU assuming almost exactly the same east-north- easterly direction. And in the small dome- ~ like p~'otrusion of fIagley Park, which lies 9 parallel to Bartestree Dyke, and precisely in ~ the axis of Shucknall Hill, we find a further ~, ~ proof of the same movement. .~ It appears probable, then, that the pressure ~ caused by the elevation of the central dome .~. of the Woolhope area, acthlg in every direc- tion, has on the north-west side caused great '~ ~ undulations in the Silurian and Devonian strata ~ which lie beyond the region of actual elevation. ~ In two instances, that of Shucknall Hill and r ~"-~'"/~]1i ~ of ttagiey Park, the denudation of the Old ~ Red Sandstone has exposed to view the sub- ~////I .~ jacent Silurian rocks on the summits of these undulations. Great shattering and disloca- tion would of course accompany these move- ments, and in the Bartestree Dyke it is inter- ii i ...... ii esting t~176176 great crevicesthns ~ formed, and filled with eruptive matter derived from the Plutonic region where all these great movements originated. The accompanying section will serve to show the relations in "which the tIagley protrusion stands to the Bartestree dyke and the Wool- hope elevation.