On the age, formation, and successive drift-stages of the valley of the Darent : with remarks on the Palaeolithic implements of the district, and on the origin of its chalk escarpment / by Joseph Prestwich.

  • Joseph Prestwich
Date:
1891
Catalogue details

Licence: Public Domain Mark

Credit: On the age, formation, and successive drift-stages of the valley of the Darent : with remarks on the Palaeolithic implements of the district, and on the origin of its chalk escarpment / by Joseph Prestwich. Source: Wellcome Collection.

Provider: This material has been provided by The Royal College of Surgeons of England. The original may be consulted at The Royal College of Surgeons of England.

    2/48 (page 126)
    On the Age, Formation, and Successive Drift-Stages of the Valley of the Darent ; with Eemarks on the Paleolithic Implements of the District, and on the Origin of its Chalk Escarpment. By Joseph Prestwich, D.C.L., F.E.S., F.G.S., &c. [Plates VI., VII., & VIII.] Contents. Page § 1. General Character and Age of the Darent Valley 126 2. The Chalk-Plateau Drifts and the associated Flint Implements. 128 3. The Initial Stages of the Darent Valley 135 4. The High-Level or Limpsfield-Gravel Stage 137 5. Contemporaneous Drift in the Cray Valley 144 h. The Brick-earths of the Darent Valley 145 7. Other Drifts of the Darent Valley; the Chevening and Dunton- Green Gravel 147 8. The Lovr-Level Valley-Gravels 151 9. The Rubble on the Sides and in the Bed of the Valley 154 10. The Alluvium and the associated Neolithic Implements I.*i6 11. On the Chalk Escarpment within the Darent District 156 § I. General Character and Age of the Darent Valley*. In former papers t I have touched incideutally upon the drift phe- nomena of this district, and on the occurrence of a peculiar group of flint implements found on the adjacent Chalk plateau. I now purpose to limit my observations to the circumscribed valley of the Darent, which I have bad more special opportunities of studying since my residence at Shoreham. This valley, including the district surrounding it, is of peculiar interest, from the circumstance that its geological histor}% beginning with pre-Glacial times, may, with few breaks, he traced to I^eo- lithic times ; as also from the light it throws upon the age of some of the Thames-Valley drifts, and from its distinctive groups of Palaeolithic implements. It is moreover free from the complication produced in the valleys north of the Thames by the presence of foreign-drift elements, for here the drift is restricted to debris derived from its own drainage-area. The Darent Valley is one of the few J which run through the Chalk escarpment into the so-called Wealden area §, though it does * A general account of the drift-beds and denudation of this valley is given by Mr. Topley in his ‘Geology of the Weald,’ pp. 188-194, and 270, in Mem. Geol. Survey (1875), to which I shall often have occasion to refer. See also Messrs. Le Neve Foster and W. Topley’s ‘ Superficial Deposits of the Valley of the Medway, etc.,’ Quart. Journ. Geol. Soc. vol. x.xi. (1865) f>p. 443-474, and the Maps of the Geological Survey. t Quart. Journ. Geol. Soc. vols. xlv. (1889) p. 270, and xlvi. (1890) p. 155. f Another of these valleys, that of the Wey, was described in 1851 by the late R. A. C. Godwin-Austen in Quart. Journ. Geol. Soc. vol. vii. p. 278. ^ Taking the Wealden area to mean physiographically the whole of the area encircled by the escarpment of the Chalk.