| Computer Code: |
HEAD |
Preferred Map Code: |
symb |
| Status Code: |
Full |
| Age range: |
Quaternary Period (Q)
— Quaternary Period (Q) |
| Lithological Description: |
Head is poorly sorted and poorly stratified, angular rock debris and/or clayey hillwash and soil creep, mantling a hillslope and deposited by solifluction and gelifluction processes. Solifluction is the slow viscous downslope flow of waterlogged soil and other unsorted and unsaturated superficial deposits. The term gelifluction is restricted to the slow flow of fluidized superficial deposits during the thawing of seasonally frozen ground. The flow is initiated by meltwater from thawing ice lenses.
Polymict deposit: comprises gravel, sand and clay depending on upslope source and distance from source. Locally with lenses of silt, clay or peat and organic material. |
| Definition of Lower Boundary: |
none recorded or not applicable
|
| Definition of Upper Boundary: |
none recorded or not applicable
|
| Thickness: |
none recorded or not applicable
|
| Geographical Limits: |
none recorded or not applicable
|
| Parent Unit: |
Mass movement deposits (MASMD)
|
| Previous Name(s): |
Head Gravel [Obsolete Name and Code: Use HEAD]
(HEG)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| none recorded or not applicable |
| Reference(s): |
| McMillan, A A and Powell, J H. 1999. The classification of artificial (man made) ground and natural superficial deposits. British Geological Survey Research Report, RR/99/04. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
|
E221
E237
E021
E014
S031
E219
E225
E203
E078
E070
E077
E181
E355
E356
E142
E024
E028
E048
S024
E268
S032
S040
S034
E059
S084
S030
S064
S074
S076
S093
S093
S097
S096
E281
E246
E341
E342
E343
E217
E264
E353
E354
E314
E326
E171
E096
E214
E327
|
