132 Reciew'i — Mesozoic Rocks of Kent Coal Exploration, 



but the delay in publication can hardly be regretted, as fresh material 

 was from time to time obtained, and the conclusions based upon an 

 immense amount of careful detailed observation and study, are of the 

 highest scientific interest and of considerable practical importance. 

 Although permission to examine the material from the boi'ings and 

 shafts was given on the understanding that the investigations were 

 not extended into the Coal-measures, nevertheless the information on 

 the distribution and thicknesses of the various Mesozoic formations 

 is all important in reference to the depth at which Palaeozoic rocks 

 are likely to be met with in areas hitherto unproved. 



The memoir is divided into two parts of nearly equal length : the 

 first, comprising " Stratigraphical Descriptions", is by Mr. Laraplugh ; 

 and the second, giving " The Palseontological Characters and Correlation 

 of the Strata between the Gault Clay and the Trias ", is by Dr. Kitchin. 

 The four localities dealt witli extend in almost a direct line from 

 Penshurst, south-west of Tonbridge, to the Dover Coal-mine in 

 Hougham parish, a distance of about forty-five miles. Eecords of 

 these borings were published by Mr. Whitaker in liis memoir on the 

 Water Supply of Kent (1908), and a comparison of the information 

 there given shows how much has been added with regard to the details 

 and correlation of the strata. 



At Dover, where the explorations were commenced in Chalk, less 

 Folkestone Beds, more Sandgate Beds, and no Hythe Beds are 

 recognized; and it is remarked by Mr. Lamplugh that there is "an 

 intensified example of the condensation of sediments under stroTig 

 current-action" in the case of the Folkestone Beds, as "although the 

 Dover area remained beneath the sea during the accumulation of the 

 Hythe Beds, the conditions were such that permanent sedimentation 

 was not possible upon it". The attenuation of the Wealden Beds 

 and the absence of Purbeck and Portland Beds are confirmed, and 

 the unconformity is further marked by much erosion of the Kimeridge 

 Clay. More Corallian is identified, the lower division, which is clayey 

 and calcareous, being taken to include tlie Cordatim zone ; and a less 

 thickness is admitted of the Kellaways formation, which has yielded 

 Sigaloceras callovietise at Tilmanstone. Tlie Lower Oolites have been 

 found caj^able of subdivision, and although Cornbrash is somewhat 

 doubtfully distinguished strong support of the presence of the 

 formation is afforded by fossils obtained from Tilmanstone north of 

 Dover ; the beds assigned to the Forest Marble also present some 

 of the characters of that formation ; the Great Oolite is clearly 

 distinguished; and the Inferior Oolite may be represented by sands 

 and calcareous grits which occur above the Upper Lias, but have 

 yielded no fossils. The Upper Lias {Serpent iit us zone), probably the 

 Middle Lias (Spinafus zone), and the Lower Lias (^Capricornus zone) 

 are noted. Below come the Coal-measures. 



At the Brabourne boring, commenced in Gault, another great series 

 of formations has been proved, the records (with that of Dover), in 

 the words of Mr. Lamplugh, being " unparalleled in Britain — or, so far 

 as our knowledge goes, in any other part of the world — in the 

 geological range and continuity of formations proved by them to exist 

 in actual superposition in a single small area". The Folkestone 



