Southern Region Chalk Group Lithostratigraphy: The North Downs (Robinson, 1986) - Glaucontitic Marl Member: Difference between revisions
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The Glauconitic Marl Member (reference section: Copt Point, Folkestone [TR 242 365] ) is c. 5 m thick at Copt Point, and comprises bioturbated glauconitic sand with phosphatic nodules (Robinson, 1986). The base of the member is an unconformable erosion surface at the contact with Lower Cretaceous strata, and the top is a nodular bed, above which glauconite ceases to be the dominant lithological component (Robinson, 1986). The name of the member follows Scanes (1916) and later authors who replaced the earlier traditional term Chloritic Marl with Glauconitic Marl, after it was realised that the distinctive green coloured mineral locally concentrated at the base of the Chalk Group was Glauconite and not Chlorite. | The Glauconitic Marl Member (reference section: Copt Point, Folkestone [TR 242 365] ) is c. 5 m thick at Copt Point, and comprises bioturbated glauconitic sand with phosphatic nodules (Robinson, 1986). The base of the member is an unconformable erosion surface at the contact with Lower Cretaceous strata, and the top is a nodular bed, above which glauconite ceases to be the dominant lithological component (Robinson, 1986). The name of the member follows Scanes (1916) and later authors who replaced the earlier traditional term Chloritic Marl with Glauconitic Marl, after it was realised that the distinctive green coloured mineral locally concentrated at the base of the Chalk Group was Glauconite and not Chlorite. | ||
Latest revision as of 12:14, 7 October 2013
The Glauconitic Marl Member (reference section: Copt Point, Folkestone [TR 242 365] ) is c. 5 m thick at Copt Point, and comprises bioturbated glauconitic sand with phosphatic nodules (Robinson, 1986). The base of the member is an unconformable erosion surface at the contact with Lower Cretaceous strata, and the top is a nodular bed, above which glauconite ceases to be the dominant lithological component (Robinson, 1986). The name of the member follows Scanes (1916) and later authors who replaced the earlier traditional term Chloritic Marl with Glauconitic Marl, after it was realised that the distinctive green coloured mineral locally concentrated at the base of the Chalk Group was Glauconite and not Chlorite.
Macrofossil Biozonation: M. mantelli Zone (Robinson, 1986)
Correlation: see Correlation with other lithostratigraphical schemes for the Southern Region
see Correlation with other UK regions
References
ROBINSON, N D.1986. Lithostratigraphy of the Chalk Group of the North Downs, southeast England. Proceedings of the Geologists' Association, Vol. 97, 141-170.
SCANES, J. 1916. Field report on excursion to Mere and Maiden Bradley in Wiltshire. Proceedings of the Geologists' Association, Vol. 27, 119-120.
See: Glauconitic Marl (Traditional Classification)