Computer Code: |
LLI |
Preferred Map Code: |
notEntered |
Status Code: |
Full |
Age range: |
Hettangian Age (JH)
— Pliensbachian Age (JE) |
Lithological Description: |
[Obsolete] Grey mudstones with concretionary and tabular argillaceous limestone, ironstone or sandstone. |
Definition of Lower Boundary: |
Base Hettangian or base Lias Group [see notes under "Geographical Limits"] |
Definition of Upper Boundary: |
Top Lower Piensbachian or base of succeeding arenaceous/calcareous strata belonging either to the Lower or Upper Pliensbachian [see notes under "Geographical Limits"]. |
Thickness: |
Unspecified |
Geographical Limits: |
The term was used loosely to signify the lower, mudstone-dominated, part of the Lower Jurassic succession now known as the Lias Group. It has been used more specifically to mean Hettangian to Lower Pliensbachian strata (chronostratigraphical, not lithostratigraphical). In this context it excluded latest Triassic beds of the basal Lias Group and included arenaceous beds (=Middle Lias of some authors) at the top of the Lower Pliensbachian. |
Parent Unit: |
none recorded or not applicable
|
Previous Name(s): |
none recorded or not applicable
|
Alternative Name(s): |
Redcar Mudstone Formation
|
Stratotypes: |
none recorded or not applicable |
Reference(s): |
Cox, B M, Sumbler, M G, and Ivimey-Cook, H C. 1999. A Formational framework for the Lower Jurassic of England and Wales (Onshore Area). British Geological Survey Research Report No. RR/99/01. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E184
E126
E263
E262
E249
E248
E234
E064
E072
E114
E127
E143
E157
E159
E161
E170
E171
E172
E185
E187
E188
E201
E202
E204
E217
E218
E220
E235
E236
E250
E251
E253
E264
E265
E279
E280
|