133

EXCURSION TO THE .

VVHITSUNTIDE, 1919. DIRECTOR\ G. W. COLENUTT,F.G.S. AND R. W. HOOLEY, F.G.S. (PLATE 8 B.) THE party, numbering 31, assembled at Ryde, Isle of Wight, on the evening of Friday, June 6th, the Headquarters being at Yelfs Hotel, Union Street, Ryde, the object of the Excursion being to make a study of the principal strata exhibited in the cliff sections at the localities set forth in the programme. 1\1r. A. W. Oke acted as Excursion Secretary.

SATURDAY, JUNE 7TT!. REPORT BY R W. HOOLEY, F.G.S. The members left Ryde by the 8.29. a.m. train for Newport, and thence by brakes to Shepherd's , Atherfield, via Shor­ well. Here the party was met by the Director. On arrival at Shepherd's Chine, the Perna Bed at the base of the Lower Green­ sand, where it outcrops in the sides of the Chine near the Military Road, received attention. The junction of the Lower Greensand with the Wealden Shales was noted. The Chine is cut out of these Shales from here to the sea-cliff. Several recent slips caused by the percolation of surface water through the mass and the undermining by the stream were seen. Thus are pro­ duced its sloping sides. Cowlease Chine was then visited. Here the shales are supported by the thick bed of sandstone Which, rising from the beach near the mouth of Shepherd's Chine, passes -out of the cliff at Barnes' High. Only in winter, or after heavy rains, do streams enter Cowlease Chine; the main work of erosion was done in former days when the Shepherd's Brook had its outlet to the sea through this Chine instead of Shepherd's Chine. Its former bed, which runs parallel with the edge of the cliff, has already been breached seawards by the fall of the cliff through marine erosion. Midway between Cowlease Chine and Barnes' High the Director explained the tectonic features of the district. A very thick sea-fog enveloped the whole of the surrounding country, obscuring its topography. The party .descended here to the beach by a rough and steep path and proceeding eastwards, the mottled marls and clays of the Lower Wealden Beds were examined. The Hypsilophodon Bed was well exposed and formed a marked band in the cliff. From the fern-bed, which overlies the thick bed of yellow sandstone in the Wealden Shales many very 134 EXCU RSION TO THEISLE OF WIGHT fine hand-specimens containin g Lonchopteris, Pecopteris, etc. "ere obtained. The paper-shales and th e seams of Cyrena limestone were examined and specimens of th e characteristic fossils collected, among which was a spine of Hybodus. The upper portion of the Shales was almost entir ely covered by an immense fall of the Atherfield Clay which had taken place during th e past winter. In places the junct ion of th e Lower Greensand with th e Weal­ den Shales was observed, but no good section was found. Speci­ mens of Modiola and the dwarfed forms of Exogyra were obtained from th e thin lime-iron-stone band occurring here. Several members collected fine crystals of selenite from th e fallen masses of Ath erfield Clay. An immens e number of blocks of th e Perna limestone had also been brought down and thickly strewed the beach. For half an hour busy hammers were en­ gaged in chiselling out the characteristic fossils. Lunch was taken at Ath erfield Point, Before studyi ng th e Lower Greensand Beds, th e Director described the section exposed from Atherfield Point to Ladder Chine. The party th en commenced to examine th e section in detail. In the Lower Lobster Bed a portion of a Cardiaster was found and a small specimen of the characteristic lobster, Meyeria oectensis. Very few of the boulders of the Cracker Rocks were visible on the beach, but many blocks were exposed in situ in th e cliff. Some were seen to be full of Geroillia anceps and several amm onites were visible in th e Cracker Group of strata, but tim e did not permit of their extraction. The Lower Gryphrea (Exogyra) Group of Fitton was work ed for fossils, and shark's teeth, the cha racteristic. brachiopods and ostraa and a very fine specimen of Ps eudodiadema were obtained. Passing eastwards, the Scaphite and Crioceras Groups were studied. A large specimen of Scapkites (Ancyloceras) was seen in one of the large characteristic calcareous blocks in the cliff, by reason of th e block having split in half owing to a fall of th e face of the cliff. Manv ammonites were observed in a ha rd calcareous bed which "runs eastwards across the beach as a reef into the sea near the mouth of . This Chine is a deep and pre­ cipitous gorge cut by the stream th at flows through it. Ascent to th e top of the cliff was made through Ladder Chine, which in form is like an amphitheatre, which has been eroded by wind action. The party thence proceeded by the Military Road to Chale, whence they drove to Newport, where tea was obtained SUNDAY, June 8TH. REPORT BY G. W. COLENUTT, F.G.S. As it was the wish of some of the members to be given an opportunity of examining the fine and complete section of Eocene AND PORTSMOUTH WATERWORKS. 135 Beds and Oligocene clays, etc., at White Cliff Bay, an unofficial excursion was arranged, and the party left Ryde by train at ILO to Brading. A pleasant walk by path led to the Cliffs at the Bay. Descending to the beach a short time was spent in examining the Chalk of Culver Cliff, which shewed fair sections of the higher zones. Attention was called to the extensive fracturing of the flints in situ and to the crushed condition of the shells of echinoderms which were found. The Eocene Beds above the Chalk were next examined. The Director pointed out the great changes which have taken place in the Bay since the Association last visited the Island in 1906, and to how great an extent the cliffs have foundered and fallen since that time as a result of the wholesale removal of shingle from the foreshore in 1904. The erosion then started has been con­ tinuous, and its progress does not show any signs of being abated. Several falls of cliff have occurred during the past winter and some of the more important strata are now partly hidden by the founders which have taken place. The beds of Eocene and Oligocene age from the 'Woolwich and Reading Beds to the Bern­ .bridge Limestone were in turn examined and the characteristic fossils collected from the horizons which yield organic remains. The lignite seam in the Bracklesham Beds was very well exposed. Attention was called by the Director to the different junctions of the several beds and to other features for comparison with the strata to be seen in the cliff section at Alum Bav, and it was pointed out how difficult it was to correctly correlate the strata at the two localities. The party walked back to Brading and took train to Ryde in the latter part of the afternoon.

WHIT MONDAY, JUNE gUT.

REPORT BY G. W. COLENUTT, F.G.S. The members left Ryde by the 8.17 train for Freshwater Station, where brakes were in readiness for the drive to Alum Bav. On arrival at the shore Mr. Colenutt gave a short account of the cliff section which shewed the whole of the beds from the Chalk of Needles Down (zone of B.mucronata), to the Bembridge Limestone at the summit of Headon Hill. Some time was spent in studying and collecting from the Headon Beds in the sloping cliff below Headon Hill, which are so singularly rich in organic remains. The Barton, Bracklesham and Bagshot Beds were in turn exa­ mined and fossils collected, and also the London Clay and the Woolwich and Reading Beds. Attention was called to the eroded surface of the Chalk at its junction with the Eocene Beds. The erosion of the floor of the Bay was noticed; this has led to the lowering of the normal level of the foreshore and has partly resulted in the undermining of the base of the cliffs. A rather extensive founder has lately taken place in a part of the cliff 136 EXCURSION TO THE ISLE OF WIGHT formed of the upper portion of the Bracklesham series, and it seems highly probable th at fur ther falls of cliff will occur in the near future. Afte r lunch the members drove in the brak es to Broo k. REPORT BY R. W. HOOLEY, F. G.S. THE part y arrived at Brook soon after 3.p.m. Here!\Ir. Hooley took sale charge. The Lower Wealden Beds of Brook Bay were investiga ted. The Cliff near being clear of talus, the lowest Wealden strata found in the Isle of Wight were well exposed. The small chine from which Hul ke obta ined many fine reptilian remains has practic ally been obliterated by th e sea during the past winter. The" Pine-raft " at Hanover Point, owing to th e tid e being at half-flood, was only partially uncovered. The large tree-trunk observed on th e last visit of the Association in 1906 was visible and many smaller porti ons of trees. Here the Director c.escribed this raft and its probable formation and the strata exposed from Hanover Point to the Western end of Compton Bay. Proceeding westwards, th e alluvium of Shippard's or Compton Gran ge Chine i was investi­ gated and specimens of hazel nuts found. (See Plate 8, fig. B.) Particular attention was directed to th e repetition of the red and mottled marls and the shales of th e Wealden strata and the faulting of the second series of the variegated beds against th e shales of the first series. The same section as figured in th e P roc. Geol. Assoc., vol. xix, 1906. p. 364 is still exposed. Aft er the examina tion of th at section, it was decided to return to the brakes to ensure the party catching the train at Ningwood, Justice, th erefore, could not be done to th e fine section to be seen in Compton Bay trorn the Wealden Beds to th e Chalk. The party retraced their steps and driving to Ningwood Sta tion entrained by the 5. 58. p.m, train for Newport, and thence to Ryde. TUESDAY, JUNE 10TH. REPORT BY G. W. COLENUTT, F.GS . THE memb ers left Ryde by the first train for Yarm outh, as the day was to be spent in examining the splendid sections of Bembridge Marls and th e Hamstead Beds in Bouldnor and Harnstead Cliffs, and on th e shore between tid e marks. While waiting for the tid e to fall th e Director gave th e members an account of the geological history of the old Solent River, and pointed out the convincing evidence in support of th e theory th at the last connection of th e Island with th e mainland was by an extension of th e land between and Studland Bay in Dorsetshire, such land having formed the southern bank of th e ancient river th e site of which is now occupied by the Solent AND PORTSMOUTH WATERWORKS. 137 Proceeding by cliff path to the summit of the cliff at Hamstead -whence fine views were obtained across the Island and the southern part of Hampshire, the atmosphere being very clear-­ the members spent some time in thoroughly working the Marine band at the top of the cliff.' Some fine examples of Ostrea calli­ [era Were obtained and also an abundance of the finely preserved fossils in theclavs and marls of the marine and estuarine series of the Hamstead Beds. Descending to the beach the way was taken along the foreshore eastward and many fossils Were col­ lected. The black band at the base of the Harnstead series was well exposed, as also were the underlying Bembridge Marls in the broken and slipped cliffs and on the shore itself. The members walked back to Yarmouth along the shore, it now being low tide, and on the way made a detailed examination of the marls of the White Band, and the underlying" platnore " clay, which has yielded many mammalian and reptilian bones. Tea was taken at Yarmouth and the members then returned bv train to Ryde, after having 'spent an interesting time in examining the unique section at Hamstead.

WEDNESDAY, JUNE IITH.

REPORT BY G. W. COLENUTT, F.G.S. As the members had a few hours to spare, a walk Was taken from Ryde to Quarr, Where one of the old quarries in Bembridge Lime­ stone has been re-opened during the last few years. The quarry is in the copse at the eastern end of Quarr Wood, and shews a section of the upper band of the Bernbridge Limestone. The rock is hard and forms a splendid building stone for walls, etc. but as it is transversely jointed at this locality it would probably be difficult to extract in large blocks for more important building work. Some portions of the section showed that the Limestone was almost entirely composed of very fine crystals of calcite, in other parts it Was crowded with the characteristic fossils in the form of casts. The members also visited the shore below Players copse, where a fair section of the Limestones of the Osborne Beds was visible. The upper band is Baggy and splen­ didly ripple marked. The party walked back to Ryde in time for an early lunch and then, at 12-40 left by the steamer for Portsmouth en route to Havant. (See p. 139.)

REFERENCES. r-inch Geological Map, Special Sheet, Isle of \Vight. 1844. IBBETSON, Capt. L B., and FORBES, Prof. ED\'V,\RD.-·" On the section between and Atherfield Point," Proc. Geol. Soc., vol. iv., p. 407. 1847. FITTON, Dr. \V. H.-" A Stratigraphical Account of tho Section from Atherfield to Rocken End, &c.," Quart. [ourn, Geol, Soc .. vol. iii., p. 289. 138 EXCURSIO N TO THE ISLE OF WI GHT.

1847. MAN TELL. D r. G. A.- " Geological E x cursion s Roun d the I sle of W igh t . &c.... Seco nd Edition r 85L T hird Editi on 1854 . 1856. F ORBES, Prof. EDWARD.-" Tertiary F luvio-rnarin e F ormat ion of the Isle of Wight," Mem , Geol. S urvey. 1862. B RISTOW. H. W .- " Geo log y. Isle of Wight ." Me m, Geol . Survey. 187°· CODRINGTON . T .- " On the Superficial Dep osits of the So uth of H ampshire a nd the Isle of Wight;' Quart . [ ourn , Geol, Soc., vol. x xvi. I87L J UDD. P ro f. J. \V.-" 'On the Punfield Formation." Quart . j O I !YI~ . Ceol. S oc., vo l. xxvii. 1872 • MEYER. C. J. A.--" On t he W ealden as a Fl u vio-la custrine F ormation , &c.,' · Quar t. J ourn. Geo l , S oc., vol. xxviii., p . 243. GARDXER. J . S.- " On t he Briti sh Eocen es and t heir Dep osit ion." Proc. Geol, A ssoc., vo l. vi., p . 83. 1880. J UDD, J . \V.- " On the Oligocene Strata of the H ampshire B asin, " Quart. J OUn! . Geol. S oc.• xxxvi. p. r3 7. wit h P I. vii. r88L KEEPING, H .• a nd T AW!\EY. E. B.-" On the Bed s of H ead on Hill and ," Quart. [ourn, Geol, Soc.• vo l. xx xvii.• p. 85, with P I. v. r888. GARD:\fER, J. S. , K EEPING H., and lVIONCKTOX. H . \V.- " The Upper Eocen e. comprising the Bart on and Upper Bagshot F ormat ions," Quar t, J ourn. Geol, Soc.• vol. x liv .• p . 578. 1889 . RE ID, C., and STRAHA!\ A.-" Geology of the Isle of Wight." by H. \V. Bristow. Second E dition. Geol. Survey M emoir. 1906 . E xcursion t o the Isle of Wight. P roc. Geol. A ssoc., vo l. x ix .• P art 9· 1908. COLE NUTT .G. \\'.- " Outline of Geol ogy of Isle of W ight," cont ri­ buted t o " A Guid e t o the Nat ural Hi story ofthe Isle of Wi ght." by Frank Morey. F .L. S. 1910. HE RRIES. R . S.- " The Isle of Wi ght "-" Geology in the Freld;" J ubilee Volume of Geol. Assoc.• chap. xviii.• p . .P4.