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Excursion to Brighton
239 EXOURSION TO BRIGHTON. JUNE 11TH, 1873.
Directors.-The PRESIDENT, HENRY WOODWARD, Esq., F.R.S., F.G.S., &c., and Professor T. RUPERT JONES, F.R.S., F.G.S. On arrival at B~g~ton the party crossed the South Downs to the "Devil's Dyke," at the summit of the escarpment overlooking the Weald; and here, illustrating his remarks by maps showing the changes in the physical geography of this part of the globe which have occurred during various geological epochs, Professor T. Rupert Jones, F.R.S., explained the theories which had been advanced to account for the denudation of the Weald. The Professor first referred to the hypothesis of the upheaval of the elliptical area of the Weald causing axial and transverse fissures in the Chalk, This upheaval gave rise to several rivers running north, and corresponding ones running south, which now drain the Wealden Area. The advocates of the sub-aerial denudation hypothesis maintain that the action of rain and rivers sufficed to complete the work of denudation; but it is contended, on the other hand, that it must have been consummated by submarine action. This latter opinion was strongly advocated by Mr. S. J. Mackie, who had very ingeniously shown the manner in which the sea would act, and form a long bay corresponding to the present Wealden Area before the formation of the Straits of Dover. The lecturer concluded by some general observations on the changes which had occurred in the physiography of this part of the globe. Mr. Woodward concurred in the opinion that Mr. Mackie's theory had scarcely received that careful consideration which it seemed to him it deserved, and adduced various phenomena that would be difficnlt to account for on the hypothesis of sub-aerial denudation alone. Returning to Brighton by way of the Western Valley and past Furze Hill, the area of the Tertiary Deposits, the party traversed the whole length of the Ooast Section, and alighted at Kemp Town to observe the" Elephant Bed," which was especially well seen in consequence of a recent fall of a portion of the Oliff. This remarkable bed, and the underlying "raised beach" resting on the undisturbed Chalk, were very attentively examined. After luncheon the new Museum was visited. The visitors were R
240
EX CURSION TO B RIGHTOY.
received by the Chairm an of the Museum Committee, Mr. Thoma s Davidson, F.R.S., and the Curator, Mr. G. Scott j and th e Davidson collection of foreign fossils and volcanic products, th e Will ett collection of Cretaceous fossils, and the contents of the Museum generally were subsequently iuspected. Mr. Woodward lucidly explained th e 'general arrangement of th e Museum, which he regarded with especial interest, as well as th e great share Mr. Davidson had taken in bringing togeth er a collection which was worthy of th e import ant town of Brigh ton. P rofessor Rup ert Jones th en discoursed on the El ephant Bed, attributing t his g reat aggr egation of Chalk debris against undisturbed Chalk t o a " bankin g up," which would be pr oduced by a reflex action of th e tid es consequent upon the obstruction of the isthmus which existed where are now the Straits of Dover. After thanks had been duly tendered and responded t o by Mr. Davidson, the Members proceeded to the Aquarium, to visit which they had been courteously invited. The remainder of th e time at the disposal of th e party was thu s instru ctively and agr eeably spent , and the return to London by the evening train concluded the day' s proceeding s.
EXCURSION TO HATFIELD. JUNE
28TH, 1873.
Director.-J. LOGAN L OBLEY, Esq., F .G.S . Though little visited as a locality of geological interest, th e neighb ourh ood of Hatfield presents sections both of th e older and of th e newer Tertiaries of considerable importance. Situated on t he northern edge of the London Terti ary Basin, Hatfield is an advantageous point of departure for a geologist who wishes to trace the juncti on line of the Secondaries and Terti ari es. To enable the Members of th e Association to traverse this line, and t o inspect the principalsection showing the junction of the beds, th e Marquis of Salisbury courteou sly threw open Hatfi eld Park. Thi s wide-spreading domain, with it s gentle undul ations, bearing oaks and elms and limes, afforded t o th e visitors a typical exampl e of London Clay scenery j while the fine old Tudor house, with memories of Queen Elizabeth,carried th eir thoughts back to the age
Directors.-The PRESIDENT, HENRY WOODWARD, Esq., F.R.S., F.G.S., &c., and Professor T. RUPERT JONES, F.R.S., F.G.S. On arrival at B~g~ton the party crossed the South Downs to the "Devil's Dyke," at the summit of the escarpment overlooking the Weald; and here, illustrating his remarks by maps showing the changes in the physical geography of this part of the globe which have occurred during various geological epochs, Professor T. Rupert Jones, F.R.S., explained the theories which had been advanced to account for the denudation of the Weald. The Professor first referred to the hypothesis of the upheaval of the elliptical area of the Weald causing axial and transverse fissures in the Chalk, This upheaval gave rise to several rivers running north, and corresponding ones running south, which now drain the Wealden Area. The advocates of the sub-aerial denudation hypothesis maintain that the action of rain and rivers sufficed to complete the work of denudation; but it is contended, on the other hand, that it must have been consummated by submarine action. This latter opinion was strongly advocated by Mr. S. J. Mackie, who had very ingeniously shown the manner in which the sea would act, and form a long bay corresponding to the present Wealden Area before the formation of the Straits of Dover. The lecturer concluded by some general observations on the changes which had occurred in the physiography of this part of the globe. Mr. Woodward concurred in the opinion that Mr. Mackie's theory had scarcely received that careful consideration which it seemed to him it deserved, and adduced various phenomena that would be difficnlt to account for on the hypothesis of sub-aerial denudation alone. Returning to Brighton by way of the Western Valley and past Furze Hill, the area of the Tertiary Deposits, the party traversed the whole length of the Ooast Section, and alighted at Kemp Town to observe the" Elephant Bed," which was especially well seen in consequence of a recent fall of a portion of the Oliff. This remarkable bed, and the underlying "raised beach" resting on the undisturbed Chalk, were very attentively examined. After luncheon the new Museum was visited. The visitors were R
240
EX CURSION TO B RIGHTOY.
received by the Chairm an of the Museum Committee, Mr. Thoma s Davidson, F.R.S., and the Curator, Mr. G. Scott j and th e Davidson collection of foreign fossils and volcanic products, th e Will ett collection of Cretaceous fossils, and the contents of the Museum generally were subsequently iuspected. Mr. Woodward lucidly explained th e 'general arrangement of th e Museum, which he regarded with especial interest, as well as th e great share Mr. Davidson had taken in bringing togeth er a collection which was worthy of th e import ant town of Brigh ton. P rofessor Rup ert Jones th en discoursed on the El ephant Bed, attributing t his g reat aggr egation of Chalk debris against undisturbed Chalk t o a " bankin g up," which would be pr oduced by a reflex action of th e tid es consequent upon the obstruction of the isthmus which existed where are now the Straits of Dover. After thanks had been duly tendered and responded t o by Mr. Davidson, the Members proceeded to the Aquarium, to visit which they had been courteously invited. The remainder of th e time at the disposal of th e party was thu s instru ctively and agr eeably spent , and the return to London by the evening train concluded the day' s proceeding s.
EXCURSION TO HATFIELD. JUNE
28TH, 1873.
Director.-J. LOGAN L OBLEY, Esq., F .G.S . Though little visited as a locality of geological interest, th e neighb ourh ood of Hatfield presents sections both of th e older and of th e newer Tertiaries of considerable importance. Situated on t he northern edge of the London Terti ary Basin, Hatfield is an advantageous point of departure for a geologist who wishes to trace the juncti on line of the Secondaries and Terti ari es. To enable the Members of th e Association to traverse this line, and t o inspect the principalsection showing the junction of the beds, th e Marquis of Salisbury courteou sly threw open Hatfi eld Park. Thi s wide-spreading domain, with it s gentle undul ations, bearing oaks and elms and limes, afforded t o th e visitors a typical exampl e of London Clay scenery j while the fine old Tudor house, with memories of Queen Elizabeth,carried th eir thoughts back to the age