Reef knoll

Source: Wikipedia, the free encyclopedia.

A reef knoll is a

sea currents
and stand freely.

Reef knolls can be divided into bioherms and biostromes. A bioherm is a landform of organic sedimentary rock enclosed or surrounded by rock of different origin.

Krumbein additionally used these terms to distinguish different shapes of stromatolites: "Distinctly bedded, widely extensive, blanketlike build-ups are biostromes. Nodular, biscuit-like, dome-shaped or columnar stromatolites are also referred to as bioherms".[4]

England

Examples on the

Bunster Hill in southern Dovedale, and also Chrome Hill and Parkhouse Hill
at the northern end.

These structures are often most clearly seen where the surrounding rocks are much softer and so can be preferentially eroded. All the Derbyshire examples quoted lie at the edge of the limestone areas; Chrome and Parkhouse lie at the divide between limestone and the much softer shale.

Examples in the Yorkshire Dales[5] lie on the downthrow side (north) of the Mid Craven Fault. There is one set located around Thorpe (Skelterton, Butter Haw, Stebden, Elbolton, Thorpe Kail, Myra Bank and Hartlington Kail); one set located around Malham (Burns Hill, Cawden, and Wedber); and a set around Settle (High Hill and Scaleber).

It was once proposed that in Lancashire, reef knolls could be seen between the villages of Worston and Downham near Clitheroe.[6][7][8]

Thorpe Kail, Stebden and Elbolton hills, against Thorpe Fell, from north east, near Hebden

See also

References

  1. ^ Cope, F. Wolverson (1976) Geology Explained in the Peak District, David & Charles
  2. ^ "Definition of BIOHERM".
  3. ^ "Definition of BIOSTROME".
  4. ISBN 978-1-4020-1597-7. Archived from the original (PDF) on January 6, 2007. Retrieved 2008-07-09.{{cite book}}: CS1 maint: multiple names: authors list (link
    )
  5. ^ Ramsbottom, W.H.C.; R.F.Goosens; E.G. Smith; M.A. Calver (1974). D.H. Rayner and J.E. Hemingway (ed.). The Geology and Mineral Resources of Yorkshire. Yorkshire Geological Society. pp. 61–64.
  6. ^ "English Nature: Lancashire Geology". Archived from the original on 2 July 2007. Retrieved 13 September 2015.
  7. doi:10.1144/pygs.38.4.607
    .
  8. ^ Kabrna, Paul. "Clitheroe Reef Belt". Craven Basin:Waulsortian Mudmounds. Craven & Pendle Geological Society. Retrieved 8 October 2015.

External links

Retrieved from "https://en.wikipedia.org/w/index.php?title=Reef_knoll&oldid=1169375049"