L. Richardson — Rhcetic Rocks of Warwickshire. 25 



Several observations that have been made by previous workers 

 suggested that an examination of the Warwickshire Rhsetic would be 

 attended by more than ordinary interest. The three main observations 

 are in effect — 



(a) The record of a peculiar bed, called the ' Guinea-Bed ', at the very base 

 of the Lower Lias, whicb, from its litbic and faunal characters, suggests a non- 

 sequence between Lias and Ehsetic. 



(6) That the White Lias proper is present in the county and in places 

 arenaceous. 



(c) That, in addition to the White Lias being arenaceous, the Black Shales 

 are in places wanting, and that tbese facts lead to the conclusion that we are 

 not far from the local margin of the deposit.^ 



It may be as well to state at once that the component divisions of 

 the Khsetic Series in Warwickshire are not subject to the considerable 

 clianges that the foregoing remarks on their supposed arenaceous and 

 attenuated condition would lead one to suppose. In brief, the Tea- 

 green Marls of the Keuper are the same as usual ; the Black Shales 

 are probably continuous through the countj^ (although more deficient 

 in hard bands than usual) ; the greenish-grey marls of the Upper 

 I'hsetic are well-developed, in places containing an JEstheria-JArnQ^^tonQ 

 rich in the characteristic phyllopod ; while above, from the neighbour- 

 hood of Wimpstone Field north-eastwards to the county-boundary, is 

 AVhite Lias — unmistakable, both as regards its lithic characters and 

 -fossil contents. Indeed, this presence of true White Lias (Langport 

 Beds) is the most interesting feature of Warwickshire Khsetic 

 stratigraphy. 



In the neighbourhood of Binton, Grafton, Wilmcote, and Bickmarsh, 

 from which, however, the White Lias is absent, occurs the ' Guinea- 

 Bed'. This is a peculiar and frequently conglomeratic stratum, its 

 lithic and faunal characters indicating a non-sequence between it and 

 the immediately subjacent deposit. Some authors have grouped the 

 bed with the Rhastic, others with tlie Lias, but fuller reference will 

 be made to this matter later. 



Above the Guinea-Bed come the alternating deposits of limestone 

 and clay in connexion with which the terms ' firestones ', Ostrea- 

 and Saurian Beds, and Insect Beds are familiar, 



Tea.-green Marls. — The line of demarcation between the Tea-green 

 Marls and the Black Shales at the few places where I have seen their 

 junction, and from all accounts, is sharply-defined, and no representa- 

 tives of the Sully Beds have been or, I think, are likely to be found. 



The Tea-green Marls themselves, as already remarked, are of the 

 usual type. Since at one end of the county, namely, at Marl Cliff, 

 they are about 24 feet thick, and at Wigston in Leicestershire, 

 beyond the northern end, about 15 feet thick, it is to be presumed 

 that in the intervening district their thickness lies between these two 

 figures. 



There are no good exposures of the Tea-green Marls now available ; 

 but I have noted exposures of minor importance at the following 

 localities : — 



^ The Jurassic Bocks of Britain — The Lias, etc., p. 151. 



