Computer Code: |
TWGR |
Preferred Map Code: |
TWGr |
Status Code: |
Full |
Age range: |
Eocene Epoch (GE)
— Eocene Epoch (GE) |
Lithological Description: |
Unbedded gravel of large, closely packed, unabraded flints in a matrix of white, locally brown-stained, clay and a little sand. |
Definition of Lower Boundary: |
Junction with underlying Upper Greensand marked by a sandy flint-free bed up to 12.5cm thick containing well rounded quartz and schorl pebbles (Pickard, 1949). |
Definition of Upper Boundary: |
Overlain by the Buller's Hill Gravel (fluvial flint gravel). |
Thickness: |
To 8m |
Geographical Limits: |
Great and Little Haldon Hill, south Devon; also occurs within dissolution pipes and hollows near Kingsteignton (Brunsden and others, 1976). |
Parent Unit: |
Haldon Gravel Formation (HGR)
|
Previous Name(s): |
Tower Wood Gravel Formation [Obsolete Name and Code: Use TWGR]
(-3735)
|
Alternative Name(s): |
none recorded or not applicable
|
Stratotypes: |
Type Section |
Tower Wood Quarry, Great Haldon, near Exeter, Devon. c.6m of gravel visible to Hamblin (1973). Quarry now degraded - only c.2m of gravel visible. |
Reference(s): |
Selwood, E B, Edwards, R A, Simpson, S, Chesher, J A, Hamblin, R J O, Henson, M R, Riddolls, B W and Waters, R A. 1984. Geology of the countryside around Newton Abbot. Memoir of the British Geological Survey, Sheet 339 (England and Wales). |
Ussher, W A E. 1913. Geology of the country around Newton Abbot. Memoir of the British Geological Survey, Sheet 339. (England and Wales). |
Hamblin, R J O. 1973. The Haldon Gravels of South Devon. Proceedings of the Geologists' Association, Vol.84(4), 459-476. |
Edwards, R A, 1991. Geology of the Dunchideock district (Devon) 1:10,000, SX88NE. British Geological Survey Technical Report, WA/91/7. |
Pickard, R, 1949. The Geology of Milber Down. Report and Transactions of the Devonshire Association for the Advancement of Science, Vol.81, p.217-226. |
Brunsden, D, and others. 1976. Tertiary and Cretaceous sediments in solution pipes in the Devonian Limestone of south Devon. Geological Magazine, Vol. 113, 441-447. |
1:50K maps on which the lithostratigraphical unit is found, and map code used: |
E339
E307
E308
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