Hostname: page-component-586b7cd67f-rcrh6 Total loading time: 0 Render date: 2024-12-02T20:52:12.910Z Has data issue: false hasContentIssue false
  • English
  • Français

On the Boundary between the Upper and Lower Cretaceous

Published online by Cambridge University Press:  01 May 2009

L. F. Spath
Get access Rights & Permissions [Opens in a new window]

Extract

The Cretaceous System of England, according to A. J. Jukes-Browne1 is “naturally divisible into two distinct and different series of strata”, namely a lower series consisting chiefly of sands and clays, and an upper series, consisting mainly of chalk. The succession on the whole is easy to unravel, and was correctly described (even before the name Cretaceous had been thought of) by Webster in his Letters, written in 1811 and published in 1816 in Sir Henry Englefield's Isle of Wight; it is almost exactly the same as we recognize it to-day. Two slight changes have been made, but they have been considered by some to be changes for the worse. Firstly, the beds to which the name“Greensand” had originally been applied by Smith and Webster2 are now called “Upper” Greensand, a term that has given rise to much confusion3; and, secondly, the “Ferruginous Sands” are now known as “Lower” Greensand, a name that was strongly condemned by workers like Fitton, Godwin-Austen, and Judd. It is on record4 that even Jukes-Browne admitted that he had long been endeavouring to do away with the awkward and misleading terms “Upper” and “Lower” Greensand ; but these names, though better not used without locality, have now become too familiar and are too useful for mapping to be abandoned entirely in favour of the more precise stage names Cenomanian, Albian, and Aptian.

Type
Articles
Information
Geological Magazine , Volume 78 , Issue 4 , August 1941 , pp. 309 - 315
Copyright
Copyright © Cambridge University Press 1941

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1 Cretaceous Rocks of Britain: I. Gault and Upper Greensand of England. Mem. Geol. Survey, 1900, p. 2.Google Scholar

2 See Judd: On the Use of the Term Neocomian. Geol. Mag., vii, 1870., 220.Google Scholar

3 Spath, On the Zones of the Cenomanian and the Uppermost Albian. Proc. Geol. Assoc., xxxvii 1926, 420.Google Scholar

4 Chatuin, C. P., The Geology of the Selborne District. Trans. S. E. Union Sci. Soc., 1938. (S. R. Natur. and Antiq., xliii), 53.Google Scholar

1 Text-Book of Geology, 3rd ed., 1893, p. 938.Google Scholar

2 Cretaceous Rocks of Britain. Vol. I: Gault and Upper Greensand of England. Mem. Geol. Surv., 1900, p. 2.Google Scholar

3 The Geology of the S.E. of England, 1833., p. 66.Google Scholar

4 Internal. Geol. Congress, Cambridge, 1885. Reports of Sub-Committees on Classification and Nomenclature, p. 61.Google Scholar

6 On Geological Boundary Lines. Proc. Geol. Assoc., iv, 1875., 262.Google Scholar

1 Op. cit., 1870, p. 220.Google Scholar

2 See in Elements de Géologie, II, 2nd ed., 1835 (302); 3rd ed., (1838) 166.Google Scholar

3 In Conybeare and Phillips, Outlines of the Geology of England and Wales, pt. 1, p. 120 (see also p. 109).Google Scholar

4 d'Aubuisson de Voisins, J. F., Trailé de Géognosie, ii, 1819., 367.Google Scholar

5 Tableau des Terrains, 1829, p. 213.Google Scholar

6 Traité de Géologie, 5th ed., 1906, iii, 1295.Google Scholar

7 A New System of Geology, London, 1829., p. 278.Google Scholar

8 Fossils of the South Downs, 1822., p. 22.Google Scholar

9 Inquiries respecting the Geological Relations of the Beds between the Chalk and the Purbeck Limestone in the S.E. of England. Ann. Phil., N.S. viii, 1824., table to p. 368.Google Scholar

10 Geological Sketch of the North-western Extremity of Sussex and the adjoining parts of Hants and Surrey. Trans. Geol. Soc. (2), ii, 1826., 106.Google Scholar

1 A Geological Memoir on a Part of Western Sussex, etc., London, 1828., pl. i, fig. 2.Google Scholar

2 Treatise on Geology, 1838., p. 153.Google Scholar

3 Elements of Geology, 1838., p. 314; 2nd ed. (1841), p. 386.Google Scholar

4 A Geological Manual, 1831., p. 254.Google Scholar

5 In Phillips, Outline of the Geology of England and Wales. London, 1818. (folio-sheet appendix).Google Scholar

6 Observations on some of the Strata between the Chalk and the Oxford Oolite in the S.E. of England. Trans. Geol. Soc. (2), iv, 1836, 105.Google Scholar

7 Ansted: Geology, ii, 1844., p. 448.Google Scholar

8 Geological Excursions round the Isle of Wight, etc., 1854, p. 128.Google Scholar

9 Manual of Geology, 1855., p. 351.Google Scholar

10 Elements of Geology, 3rd ed., 1851, p. 209.Google Scholar

11 The original subdivision was maintained by many geologists, from Portlock Rudimentary Treatise on Geology, 2nd ed. 1852, p. 152). 152), and Ansted, Tennant, and Mitchell (Geology, Mineralogy, etc., 1855, p. 106), to Page (Advanced Text-Book of Geology, 5th ed., 1872, p. 306).Google Scholar The original subdivision was maintained by many geologists, from Portlock Ansted, , Tennant, , and Mitchell, Geology, Mineralogy, etc., 1855, p. 106Google Scholar The original subdivision was maintained by many geologists, from Portlock Advanced Text-Book of Geology, 5th ed., 1872, p. 306).Google Scholar

1 Students Manual of Geology, new ed., 1862, 602. Jukes was apparently unaware of the existence of Brongniart's Arenaceous System.Google Scholar

2 Loc cit., pp. 307–8.Google Scholar

3 Versteinerungen des norddeutschen Kreidegebirges. ii, 1841., 126.Google Scholar

4 Géblogie, in Corns élémentaxre d'histoin naturelle, 5th ed., Paris, 1851., p. 232.Google Scholar

5 Lehrbuch der Geognosie, ii, 1854, 915.Google Scholar

6 Traité de Géologie, ii, fasc. 2, 1164.Google Scholar

7 Tableau synchronistique des terrains crétacés. Zürich, 1872.Google Scholar

8 Chronographe géologique, 2nd ed., 1896 (C.R., 6th Internat. Geol. Congress), 564.Google Scholar

9 In Freeh, Lethaea geognostica. II, Mesozoicum, 3., i, 1907., 2.Google Scholar

1 Internal. Geol. Congr. Cambridge, 1885, Reports of Sub-Committees on Classification and Nomenclature, 61Google Scholar

2 The Classification of Stratified Rocks. Geol. Mag., 1885, p. 297.Google Scholar

3 A Review of the Speeton Clays. Proc. yorks. Geol. Soc, xx, pt. i, 1924., 13.Google Scholar

4 Type Ammonites, iv, 1922., 15.Google Scholar

5 See Table of British Strata in A Short Guide to the Museum of Practical Geology 3rd ed., 1922, p. 42.Google Scholar