426 



NA TURE 



{August y , 1882 



Below this no fossils found. 



The Park on East side of Selsea and the Mixen Rocks. 



On the east side of the Selsea peninsula, the highest bed seen 

 is the Nitnimulina larvigata bed, rich in fossil. All the succeed- 

 ing beds down to the Venericardia planicosta bed are usually 

 exposed at "the Park" 



Mixen Rocks. — A ledge, one mile south of Selsea Bill, com 

 posed of a Miliola and an Alveolina, continuation of No. 22(b) 

 only more calcareous. 



Bournemouth Area. 

 The geology of this remarkable area has received attention 

 from several explorers. Sir Charles Lyell in 1826, Professor 

 Prestwich in 1848, the Rev. O. Fisher in iS6r, and in the year 

 1878 Mr. JohnStarkie Gardner prepared and read an able paper 

 on the "Description and Correlation of the Bournemouth beds." 

 Part I., the Upper Marine Series (Quarterly Journal of the 

 Geological Society, vol. xxxv. pp. 202-228. 1879.), treating of 

 the coast section between Bournemouth and Highcliff; and a 

 second paper, Part II., on the ljwer or Freshwater series 

 (Quarterly Journal of the Geological Society, vol. xxxviii, pp. 

 I-15.). He states his reason for differing from the previuus 

 writers upon the succession of the beds and their correlation 

 with other localities. Mr. Gardner's researches endeavuur to 

 show that the celebrated Bournemouth leaf-beds immediately 

 underlie the true Bracklesham series, and are, unlike those of 

 Alum Bay, of Middle and not of Lower Bagshot period, hitherto 

 the received view as to their age. The author has also ascer- 

 tained that a great portion of the cliffs between Hengistbury 

 Head and Bournemouth are of marine origin, and highly fos- 

 siliferous. These marine beds comprise two distinct characters, 

 which the author traces across to Alum Bay in the Isle of Wight. 

 Mr. Gardner also differs from the Geological Survey in believing 

 "that the so-called Upper Bagshot beds of the London bain 

 do not belong to that series, but are the equivalents of his 

 Boscombe sands, these sands, and the marine Bournemouth beds 

 being, according to his researches, the western equivalents, or 

 extreme shore-condition of the Bracklesham sea." 



At Highcliff, nearly under Rothsay Castle, both the Baitor. 

 and the Bracklesham series are exposed, the Barton being not 

 more than 10 feet in thickness, and the subjacent Bracklesham 40 

 feet. The section is revealed to the sea-level, and therefore 

 highly instructive. The Highcliff sands conformably underlie 

 the Barton and Hordwell serie- at an angle of 2° to the E. The 

 remarkable promontory of Hengistbury Head is mainly composed 

 of strata contemporaneous with the Bracklesham series ; and 

 which Mr. Gardner would for convenience call the Bournemouth 

 beds. Hengistbury promontory in shape resembles a parallelo- 

 gram obliquely truncated at its northern extremity. The cliffs 

 facing the sea on the south are about 50 feet high, increasing to 

 IOO feet on the north, both presenting bold escarpments to the 

 sea. " The succession of the strata at Hengistbury Head, read- 

 ing upwards, comprises, I, the Boscombe sands; 2, a lower 

 series of sand with green grains, and an upper bed with iron- 

 stone ; and 3, the white Highcliff sand. The white sands at 

 Highcliff are 30 feet thick, being 12 feet thinner than the equiva- 

 lent beds at Alum Bay, where they measure about 42 feet." The 

 lowest series in the cliffs at the headland Mr. Gardner terms the 

 " Boscombe sands," which without any doubt repJcsents the 

 chief mass of brilliantly coloured sands, about 750 feet thick, at 

 Alum Bay, known to all explorers of the island. These coloured 

 sands are numbered 25 and 26 in Profess >r Prestwich's section of 

 the vertical beds in Alum Bay (Vide Quarterly Journal of the 

 Geological Society, vol. ii.). Mr. Gardner also notices another 

 hill similar in contour to that of Hengistbury, about three miles 

 to the north of the Head. This, St. Catherine's Hill, possesses 

 like the headland, similar physical features, being flat-topped 

 and having abrupt escarpments on all sides, and 160 feet high. 

 Both the Highcliff sand and the Hengistbury beds occur in this 

 hill, showing their connection and continuity inland with the 

 coast section. " The correlation of the Hengistbury Head scries 

 on the mainland with those of Alum Bay across the Solent 

 admits of little doubt, and they would appear to be represented 

 at Alum Bay by the Higluliff sands, 25 feet in thickness, and 

 equivalent to bed No. 28 in Prof. Prestwich's section. The 

 Hengistbury Head beds appear to be the equivalents of bed No. 

 27 in the Alum Bay section. The Boscombe sands represent 

 beds No. 26 and 25 of Prestwich in Alum Bay, where they are 

 l<;o feet thick. It can be conclusively seen from examination of 



the cliffs in the Bay from Hengistbury to Bournemouth that there 

 is a general sequence, and that the strata have an amount of dip 

 or inclination, sufficient in so extended a distance to expose two 

 complete series of beds, the upper series, being the continua- 

 tion of the Boscombe estuarine sand-, 100 feet thick, and the 

 lower series of sands and clays, of marine origin, which Mr. 

 Gardner has provisionally termed the Bournemouth marine 

 beds." With Mr. Gardner's paper in hand the most minute 

 details of the coast may be followed (Loc. cit. 217-226.), from 

 the Head towards Bournemouth. These, both for physical and 

 pakajontological details, I must therefore refer to you, as giving 

 step by step an analysis of the structure of the ciiffs, and the 

 flora contained in the clays and sandy series of which they are 

 composed. This flora of the Bournemouth bed n arine may be 

 referred to the Middle Bagshot series, and the Bracklesham 

 division, possibly representing the same stage in the London 

 basin, and it would appear from careful consideration of the 

 Middle and Upper Bagshots that no Eocene beds younger than 

 the Bracklesham are met with in the London area, a geological 

 fact of much significance as compared with the complete succes- 

 sion of the 'Eocene series as developed in the Hampshire basin, 

 and that of their equivalents in the basin of Paris. Mr. Gardner 

 believes that "the fossil plant remains of the Bournemouth beds, 

 especially those in the marine s eries, are of the same age as 

 tho e in the Bovey Tracey deposits, which have been wrongly 

 assigned to the Miocene period, believing, in fact, that they are 

 simply an outlier of the Bournemouth series, now 80 miles to the 

 west," but formerly and originally connected as a western 

 extension of the Bournemouth deposits. 



Comparison uf the flora of the two areas shows a close 

 affinity, if not identity of species, Uimunda lignata, Lastraa 

 Bunbwyi, Palinacites desmonorops, the fruit, conifers, and dico- 

 tyledons being not only specifically identical, but occur in the same 

 combinations and manner of preservation," loc. cit. pp. 227, 

 228. Polypodium, Chry sodium, Pteri>, and Osmunda, amongst 

 the ferns ; Eucalyptus, branches of Sequoia, pods and leaves 

 of the Legumino se, Nipadites, Dryandra Cacti, Anona, 

 Hightea, &c, occur in the beds constituting the western termi- 

 nation of the Bournemouth marine series. The fauna testifies to 

 its marine derivation : the genus Oslna, Area, Modiola, Tellina, 

 Calyptrcca, Phorus, Natica, and Ceri hium. The Crustacea, 

 through Callianassa, and a shore crab, with Bryozoa ( Flustra), 

 needs no other comment. The changing physical characters of 

 the beds of the Bournemouth series, both horizontally and 

 vertically, the mar-hy character of the flora, "as represented 

 by the ferns, aroids, Eucalyptus, &c, the patches of clay, in 

 which the water-plants, ferns, &c, may have rooted, the local 

 patches of ironstone, the intercalated marine beds and their 

 fauna mingled with uni s, clearly shows that this was the debate- 

 able ground between sea and r.ver, beyond which to the west it 

 would appear the sea never then penetrated." In February of 

 the prtsent year, Mr. Gardner communicated to the Geological 

 Society bis second paper on these Bournemouth beds, being a 

 continuation of his former notice, but in this his researches are 

 confined to the history of the "Lower or Freshwater Series" 

 (Quarterly Journal of the Geological Society, vol. xxxviii.) of 

 the Bournemouth area. The author describes the geological 

 structure of the Eocene cliffs as far as Poole harbour. All the 

 strata between Bournemouth and Poole harbour are of fresh- 

 water origin, and are highly interesting on account of the fossil 

 flora recently obtained from them by Mr. Gardner— undoubtedly 

 the mo-t extensive, richest, and most varied hitherto discovered 

 or extracted from the Tertiary formations. No leis than nine- 

 teen species of ferns have been described from these beds. 

 Only ten species have been met with in all the other British 

 Eocene deposit-, including the famous Bovey Tracey beds, and 

 three of these ten are also found at Bournemouth. Sir C. 

 Lyell, in 1827, the Rev. P. B. Brodie, in 1842, Mantell, in 

 1S44, Prof. Prestwich, in 1847, Trimmer, in 1855, De la 

 Harpe, in 1856, and Heer, in 1859, have all written upon the flora 

 and its associated conditions, origin, &c. In 1862, the Geological 

 Survey, through the Memoir by Forbes and BrLstow upon the 

 Lie of Wight, held the view that the fos-il flora of Bournemouth, 

 Corfe, and Alum Bay, were identical, although few species 

 were common to these localities. "The cliffs comprising the 

 Bournemouth freshwater series extend from Poole harbour on 

 the west, to beyond Bournemouth, and pre.-ent escarpments 

 averaging about 100 feet in height, composed of yellow, white, 

 orange and black sands and clays, crowned with fir-trees or 

 pine woods. 



