Thin silty deposits are widespread in N. E. Essex. They are thickest on the coast at-the Naze where they reach nearly 1.5 m. These deposits overlie fluvial sands and gravels though in a number of localities there is a layer of aeolian sand (cover-sand) between the silt and the gravel. Up to 70% of the particle size distribution is within the silt fraction (2-63 um) which is consistent with aeolian transport and so these deposits are probably of loessial origin. Although the majority are classified as sandy loess, the loessial , sediments of N. E. Essex are a textural continuum ranging from loess to sediments approaching aeolian sand in composition. This reflects the degree of inter-mixing of overlying loessial silt with underlying cover-sand. The loess is texturally similar to that in Kent but the sandy loess, typical of inland parts, resembles deposits in Norfolk. The heavy mineral content of loessial sediments is uniform throughout N. E. Essex and the mineralogical similarity of the loess to underlying aeolian sand indicates the same sources supplied the silt and sand fractions of both sediments. The coarse silt fraction of N. E. Essex loess is like that of loesses elsewhere in Eastern England and those of the Netherlands and Belgium which suggests a common origin. The North Sea Basin is the likely source and a possible deflation area north-east of the Dogger Bank is suggested. Differences in the heavy mineral content of the sand fractions of loesses from N. E. Essex and Norfolk probably reflects their derivation from more local sources. N. E. Essex loess is Devensian and accumulation probably commenced at about the maximum extent of Devensian ice (about 18,000 Yr. B. P. ) and continued until about 14,000 Yr. B. P. A correlation with Cover-Loams I and II of Belgium which are -Pleniglacial B of the Weichselian, (Devensian) is suggested.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:546282 |
| Date | January 1977 |
| Creators | Eden, Dennis N. |
| Publisher | University of East Anglia |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
Page generated in 0.0019 seconds