i88 



HARDWICKE'S SCIENCE-GOSSIP. 



when, their nature being clearly ascertained, the 

 boring was stopped. The fossils of these coloured 

 beds, which included Spirifera disjuncta, Rhynchondla 

 cuboides, and species of Edmondia, Chonetes, and 

 Ortliis, show them to be of Devonian age. Thus, 

 the existence of Paleozoic rocks at an accessible 

 depth under London, and the absence of the Jurassic 

 series, as maintained long since by Mr. Goodwin- 

 Austen, is experimentally demonstrated. These facts 

 are of interest in connexion with the question of the 

 possible extension of the coal-measures under the 

 Cretaceous and Tertiary strata of the south-east of 

 England. The beds found at the bottom of Messrs. 

 Meux's boring are of the same character as the 

 Devonian strata which everywhere accompany the 

 coal-measures in Belgium and the north of France, 

 being brought into juxtaposition with them by great 

 faults and flexures. The author refers especially to 

 a remarkable section at Auchy-au-Bois, in the western 

 extremity of the Valenciennes coal-field, which is 

 particularly interesting from its furnishing evidence 

 that the Hardinghen coal-field, between Calais and 

 Boulogne, is a prolongation of that of Valenciennes, 

 and because the same strike and a prolongation of 

 the same great fault observed at Auchy-au-Bois through 

 Hardinghen would carry the southern boundary of 

 any coal-field in the south-east of England just south 

 of Maidstone, thence passing a little north of London. 

 Hence it is in the district north of London that there 

 is most probability of the discovery of the Carboni- 

 ferous strata. The extent of country in which shafts 

 could be sunk to the Paleozoic strata will, however, 

 be limited by the presence of the water-bearing 

 Lower Greensand, which probably reaches close to 

 London in the south, reappears in Buckinghamshire 

 and Bedfordshire, 30 or 40 miles north of London, 

 and probably extends some distance towards the city 

 under the chalk hills of those counties and Hertford- 

 shire. The nature of the representative of the Lower 

 Greensand in the boring, and the character of the 

 fossils contained in it, lead the author to the conclu- 

 sion that in it we have a deposit produced near the 

 shore of the Neocomian sea, here probably consisting 

 of cliffs of Devonian (or Carboniferous) rock. From 

 these cliffs the calcareous material which here replaces 

 the usual loose sands of the Lower Greensand was 

 perhaps derived by the agency of springs ; and the 

 shore-line itself must be situated between the south 

 end of Tottenham Court-road and the Kentish Town 

 boring. The sandy beds of the Lower Greensand 

 will probably be found to set in at no great distance 

 to the southward, presenting the conditions neces- 

 sary for storing and transmitting underground waters. 

 A test boring made by Mr. H. Bingham Mildmay at 

 Shoreham-place, about 5 miles from Sevenoaks, and 

 in which the Lower Greensand was met with at about 

 the estimated depth (450 feet) and furnished a supply 

 of water, seems to confirm these views. At the close 

 of Prof. Prestwich's paper, Mr. CharlesMoore, F.G.S., 



remarked that the various deep well-borings around 

 London have abundantly proved the correctness of 

 Mr. Godwin-Austen's inference that the Palceozoic 

 axis of the Mendips is continued beneath the Secon- 

 dary rocks of the south-eastern counties. Mr. Moore 

 has himself shown that where these Palaeozoic rocks 

 finally disappear under the Secondary strata, there 

 are found at the unconformable junction of the two 

 formations a set of deposits indicating the existence 

 of very peculiar physical conditions, and containing 

 an admixture of fossils from very different geological 

 horizons. Hence he was led to inquire whether any 

 trace of similar abnormal deposits might be found in 

 the deep well-borings of London. With this view he 

 set to work at washing some of the materials supplied 

 to him from Meux's well, and studying the minute 

 and often microscopic organisms thus obtained. The 

 Chalk was not particularly examined ; but from a 

 single small sample of Upper Greensand he obtained 

 numerous Foraminifera and Entomostraca, including 

 one Cyprid new to science. The Gault yielded 16 

 genera and over 30 species of Foraminifera, and 20 

 species of Entomostraca, 4 of which are new, together 

 with many young forms of Gasteropods and Cephalo- 

 pods. But the chief interest of Mr. Moore's investi- 

 gations centres in the 67 feet of strata intervening 

 between the Gault and Devonian. In this marly 

 and oolitic-looking deposit he found no less than 85 

 different kinds of organisms, exhibiting a singular 

 admixture of marine and lacustrine forms of life. 

 Foraminifera are rare, but Entomostraca and Polyzoa 

 are very abundant. Some genera are found, such as 

 Carpentaria, Saccamniina, Thecidium, and Ztflania, 

 of which the range in time is greatly extended by 

 these investigations. The author fully confirms 

 Mr. Etheridge's reference of the beds in question to 

 the Neocomian period, widely as they differ in 

 physical characters from the Lower Greensand strata 

 of the south-east of England. From a careful study 

 of the nature and condition of preservation of the 

 minute organisms, he concludes that the deposits 

 which contain them were formed at first in shallow 

 lacustrine hollows on the surface of the Devonian 

 rocks now lying buried at a depth of 1,000 feet below 

 London, and that these lakes were invaded by the 

 waters of the Neocomian sea, with the deposits of 

 which their sediments were in part mingled, and 

 under which they were finally buried. Prof. Ramsay 

 said that as the South Wales coal-field, the Bristol 

 coal-field, and the Forest of Dean coal-field were 

 basins originally continuous, and only separated by 

 denudation, Mr. Prestwich and himself had agreed 

 before the Royal Coal Commission that coal-fields 

 might exist below the Secondary strata to the east- 

 ward. The correctness of this opinion was proved 

 by the boring put down by Mr. Fox at Burford, in 

 Oxfordshire, which reached undoubted Coal-measures. 

 Prof. Ramsay thought that one of these coal-fields 

 might yet be found near London by penetrating the 



