The BGS Lexicon of Named Rock Units — Result Details

Acklinton Till Formation

Computer Code: ANTI Preferred Map Code: notEntered
Status Code: Full
Age range: Devensian Stage (QD) — Devensian Stage (QD)
Lithological Description: Typically very still, dark brown or purplish brown, stony silty sandy clay diamicton with moderately well, to well-dispersed clasts mainly of brown Fell Sandstone, pinkish grey calcareous siltstone (cementstone), limestone and dolerite with other Carboniferous lithologies (yellow sandstone, black mudstone, coal and white silicified sandstone seatearth), purple porphyry and andesite from the Cheviots,wacke sandstone and wacke siltstone from the Southern Uplands.The till is commonly weathered reddish brown and decalcified at the top, locally with vertical prismatic jointing.The till typically includes ribbon-shaped lenses (palaeochannels) of gravel, fine- to medium-grained, cross-laminated sand and laminated silt and clay, typically in fining-upwards sequences that have been increasingly subglacially sheared, folded and glacitectonized upwards.The lenses typically are up to 1.5m thick (locally <12m), and have planar horizontal contacts with overlying till units. Up to seven cyclic sequences have been recorded.
Definition of Lower Boundary: Generally a sharp uneven contact on bedrock, but locally a complex gradational glaciotectonic contact with fractured or decomposed bedrock. Locally a sharp, uneven to planar horizontal contact with orange brown sand and gravel of the Maiden's Hall Sand and Gravel Formation.
Definition of Upper Boundary: Ground surface or unconformable contacts with younger superficial deposits.Towards the coast the formation is capped by very stiff,dark brown or purplish brown weathering to reddish brown,stony silty sandy clay diamicton containing clasts similar to the Acklinton Till, but including shell fragments (Horden Till Formation).The contact is either gradational or a sharp, planar, unconformable contact.
Thickness: Up to 25m.
Geographical Limits: The coastal lowlands of Northumberland, north of thr River Tyne, but excluding the coastal fringe underlain by the Horden Till Formation.
Parent Unit: North Pennine Glacigenic Subgroup (NPEG)
Previous Name(s): none recorded or not applicable
Alternative Name(s): ACKLINTON FORMATION OF BOWEN (1999)
Stratotypes:
Type Section  Drift-filled buried valley exposed in former Maiden's Hall opencast coal site,13km NNE of Morpeth, Northumberland. 
Partial Type Section  Logged sections in the former Acklinton Opencast Coal Site, 17km NNE of Morpeth, Northumberland. 
Reference(s):
Stone,P D, Merritt,J W, and Millward D. In press. British Regional Geology:Northern England (Third Edition). British Geological Survey, Nottingham. 
Eyles,N, Sladen J A, and Gilroy,S.1982. A depositional model for the stratigraphic complexes and facies superimposition in lodgement tills. Boreas, 11, 317-333. 
Eyles,N, and Sladen,J A.1981. Stratigraphy and geotechnical properties of weathered lodgement till in Northumberland, England. Quarterly Journal of Engineering Geology, London, 14, 129-141. 
Bowen,D Q(Ed.) 1999. Northen England. 91-98 in Correlation of Quaternary deposits in the British Isles.Geological Society of London Special Publication No 23. 
McMillan,A A, Hamblin,R J O,and Merritt, J W. in prep (2009). A lithostratigraphical framework for onshore Quaternary and Neogene (Tertiary) deposits of Great Britain and the Isle of Man. British Geological Survey Research Report. 
1:50K maps on which the lithostratigraphical unit is found, and map code used:
none recorded or not applicable