Category:Chalk Group Lithostratigraphy: Marlborough Downs/Berkshire Downs/Chilterns

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The Chalk Group of this region has some distinct lithostratigraphical features compared to adjacent areas. In the Lower Chalk, an erosive calcarenite (Totternhoe Stone) has removed part of the succession, and in the Middle and Upper Chalk there is a variably developed series of hardgrounds (the Chalk Rock & Top Rock), that condense out parts of the thicker successions seen in the Southern Region. The lithostratigraphical scheme of Bristow et al. (1997) remains largely untested over the region (Wood, 1996), parts of which have recently been mapped by the BGS (e.g. Shephard-Thorn et al., 1994) following the traditional tripartite subdivision of the Chalk outlined by Jukes-Browne & Hill (1903, 1904). The following summarises the lithostratigraphical nomenclature applicable to the region:

Lithostratigraphy for Berkshire Downs/
Marlborough Downs/Chilterns
FORMATION MEMBERS KEY MARKER BEDS





Upper Chalk







(Clandon Hardground)






(Top Rock)
Chalk Rock)






(Melborm Rock)



Middle Chalk



Lower Chalk Plenus Marls

Grey Chalk

Tottomhoe Stone
Chalk Marl
Glauconitic Marl/Cambridge
Greensand

References

BRISTOW, C. R., MORTIMORE, R. N. & WOOD, C. J. 1997. Lithostratigraphy for mapping the Chalk of southern England. Proceedings of the Geologists' Association, Vol. 108, 293-315.

JUKES-BROWNE, A J & HILL, W.1903. The Cretaceous rocks of Britain. Vol. 2 - The Lower and Middle Chalk of England. Memoir of the Geological Survey of the United Kingdom.

JUKES-BROWNE, A J & HILL, W.1904. The Cretaceous rocks of Britain. Vol. 3 - The Upper Chalk of England. Memoir of the Geological Survey of the United Kingdom.

SHEPHARD-THORN. E. R., MOORLOCK, B. S. P., COX, B. M., ALLSOP, J. M. & WOOD, C. J. 1994. Geology of the country around Leighton Buzzard. Memoir of the British Geological Survey, Sheet 220 (England & Wales).

WOOD, C. J. 1996. Upper Cretaceous: the Chalk Group. In SUMBLER, M. G., British Regional Geology: London and the Thames Valley. Fourth Edition. (London: HMSO for the British Geological Survey).

Pages in category ‘Chalk Group Lithostratigraphy: Marlborough Downs/Berkshire Downs/Chilterns’

The following 17 pages are in this category, out of 17 total.