| Computer Code: |
RSTI |
Preferred Map Code: |
notEntered |
| Status Code: |
Full |
| Age range: |
Devensian Stage (QD)
— Devensian Stage (QD) |
| Lithological Description: |
Gravelly sandy clay diamicton, compact and massive, matrix-supported, generally reddish brown. The diamicton contains well dispersed angular to well rounded clasts of red sandstone, Borrowdale Volcanic Group rocks, Skiddaw Group slates, limestone and yellow and white Coal Measure sandstones, coal, granophyre, granodiorite (?Criffel) and greywacke sandstone. The member also contains "rip-up" clasts of underlying deposits and its composition can vary considerably locally (being largely determined by the nature of the underlying sequences from which it is mainly derived). |
| Definition of Lower Boundary: |
Unconformable on older-Quaternary deposits and its base is commonly repeated by small-scale thrusting. At its type section and other sites within the buried valleys of the Ehen, Calder and Lower Uldale, the Rothersyke Till Member overlies the Ehen Valley Sand and Gravel Member of the Seascale Glacigenic Formation. |
| Definition of Upper Boundary: |
Commonly the ground surface, but at its Type Section the Member is overlain by the Low Mill Gravel Member of the Gosforth Glacigenic Formation, and at other localities, by the Peel Place Sand and Gravel Member of the Gosforth Glacigenic Formation or by Holocene deposits such as peat and alluvium. At its Reference Section the upper surface of the till (the ground surface) displays a polygonal pattern of thermal contraction cracks (relict tundra patterned ground). In the coastal area north of Sellafield, the gravelly reddish brown Rothersyke Till Member is overlain (or is cut out by) the sandy and clayey How Man Till Member of the Gosforth Glacigenic Formation. |
| Thickness: |
Typically 1.0 to 2.0m |
| Geographical Limits: |
On 50k Sheets 28 (Whitehaven) and 37 (Gosforth). |
| Parent Unit: |
Gosforth Glacigenic Formation (GOGL)
|
| Previous Name(s): |
Upper Boulder Clay [Obsolete Name and Code: Use FWTI, GOGL, HMTI, PKSA, PLBT, RSTI, STPTG]
(-4662)
|
| Alternative Name(s): |
none recorded or not applicable
|
| Stratotypes: |
| Type Section |
"Rothersyke Scar" river cliff section on the western side of the River Ehen, between Rothersyke House and Low Mill; c.300m west of Thornhill village, west Cumbria. Nirex Scient Report SA/97/045 (Issue 2.0). 1997. |
| Reference Section |
Trial pit at Rakes, c.800m northnorthwest of the centre of the village of Beckermet, west Cumbria. Log NY00NW ME23, Nirex Science Report 768, 1995. |
| Reference(s): |
| Merritt, J W and Auton, C A. 1997. Quaternary lithostratigraphy of the Sellafield district. Nirex Science Report SA/97/045 (Issue 2.0). [Report prepared for UK Nirex Ltd. 69pp, 5 tables, 20 figures, 14 enclosures and one appendix.] |
| Merritt, J W, Auton, C A, Browne, M A E, Neilson, G and McMillan, A A. 1995. Characterisation of the onshore Quaternary deposits around Sellafield, Cumbria, Phase II. Nirex Science Report 768. |
| Eastwood T, and others. 1968. Geology of the country around Whitehaven. Memoir of the Geological Survey of Great Britain, Sheet 28 (England and Wales). |
| Trotter, F M, Hollingworth, S E, Eastwood T and Rose, W C C. 1937. Gosforth District. Geological Survey Memoir, England and Wales, Sheet 37. |
| 1:50K maps on which the lithostratigraphical unit is found, and map code used: |
| none recorded or not applicable |
