Outlines of the geology of England and Wales. With an introductory compendium of the general principles of that science, and comparative views of the structure of foreign countries ... / By the Rev. W.D. Conybeare ... and William Phillips ... Part I.

  • Conybeare, William Daniel, 1787-1857.
Date:
1822
Catalogue details

Licence: Public Domain Mark

Credit: Outlines of the geology of England and Wales. With an introductory compendium of the general principles of that science, and comparative views of the structure of foreign countries ... / By the Rev. W.D. Conybeare ... and William Phillips ... Part I. Source: Wellcome Collection.

    145/558 (page 63)
    On the Connexion of the Chalk with the more recent beds. 63 ash-coloured sand formerly described: here, therefore, the transition from the chalk to the more recent formations appears to have been abrupt, not gradual; in a few instances however a bed of intermediate character, a cretaceous marie* is in- terposed at the junction, which may seem to countenance this idea,—-that where the series of deposits was permitted, from the circumstances under which they were formed, to proceed quietly, such a gradation may have taken place.f (C.) The result of these repeated destructions of the chalk, has probably re- 'he f,Xtent actually occupied by this formation to much narrower nuts than those which it formerly possessed. On the north of Northamp- ns nre, and borders of Rutland and Leicestershire, and in the vale of bhipston m Warwickshire, extensive accumulations of chalk-flints, mixed Jo warrant rt -gfmentS of bard chaJk> °ccur in such quantities as almost to warrant the inference that this formation once existed in situ on these south* rwT n6f|r-y xt° T 68 from, !ts n^rest point. In the fields on the fnf;’ Sywell in Northamptonshire, the fragments of chalk are so abun- tuniPHS * * 8 f V^the aPPearance of a regular substratum of that substance, rned up by the plough. In the Philosophical Transactions for 1791, is an acccunt of a cha k pit found at Redlington in Rutland; which, if cor- rect, must be considered as a relict of this destroyed tract. The account is lorr^ii?JeC1fefhinf1CateS-a suffi^ie.nt knowledge of the general nature and fofmat,?n> .and 18 su-h as to render the testimony very respectable; but the point is so important that further inquiries are desira- t r ? Ch^-k “ deuscnbed as regularly interstratified with flints; and the infprb!ndini>dlS-tn^ being entirely occupied by the ferruginous sands of the It 7°), ’ !® notueasy to conceive that it could have afforded any C-T d htVC beCn ™lstaken for chalk. Another detached patch on Vhp L ^ samePIace>t0 exis* near Stukely in Huntingdonshire the banks of the Turnpike road, but no particulars are given, and here stance!rie(ce)0f Ca CareOUS beds miSht be confounded with this sub- r l* Af ^b?lk-marle. wlthout flints, is the stratum which in Alum Bay in the IhP frnTlgh^ UeS 'mmedia^ely next on the flinty chalk. It pulverizes with the frost, and as the rains have washed it down, its situation is marked by deep hollow. (G. T. vol. n. p. 178.) There appears also to be indica- tions of its existence in the same position in other parts of the chalk basin of the Isle of Wight (hereafter to be described); for in many parts of Sussex, south of the South Downs, as at Emsworth, Lavant, Siddleshani outh and North Bersted, Middleton, See. there are pits of a marie without flints which is evidently over the chalk: the same marie has also been found in Dorsetshire on the west of Corfe castle: but it has not been dis- covered upon it in the London basin. (G. T. vol. ii. p. 178.) S0ntiuentt’ the calcareous beds which repose on the chalk at ch^lW ht\-h°U^gh thCy cannot Pr°perly be classed as a portion of the alk formation (an attempt which has been made by some foreign writers, °n^Ktend t0 effusion), yet they certainly approach much more remaint0 hf anJ- °ther of the suPenor formations, and their organic lams seem to indicate a greater antiquity than belongs to any of the