Geological characterisation of the area around Ince Marshes, Cheshire

View across the Cheshire energy research field site, perspective looking westwards from Helsby Hill

The BGS has been characterising the geology in the Ince Marshes area of Cheshire where one of the proposed UK Geoenergy Observatory sites will be located. The following gives a brief description of the geology in the area, with links to detailed reports giving further information.

The proposed UK Geoenergy Observatory Cheshire energy research field site is located between Stanlow Oil Refinery, Helsby and Dunham-on-the-Hill in Cheshire, and the Manchester Ship Canal, on a tract of gently undulating ground adjacent to the River Mersey.

Note on released interpretations and BGS data: The geological understanding, maps and models that describe the Ince Marshes area are based on a range of legacy data including borehole logs, interpretations of outcrop and borehole material, and subsurface geophysical data. These maps and models will be updated as new data improving the understanding becomes available. The area was geologically mapped during the 1930’s, with Quaternary geology revised during the 1970’s. The geology of the area has been reappraised using 3D mapping technology to generate a 3D model of the Quaternary deposits.

The Cheshire energy research field site is located on the northern margin of the Cheshire Basin, and comprises a variable thickness of Made Ground and Devensian-aged Quaternary Deposits. These rest on approximately 250 to in excess of 1000 m of faulted Permo-Triassic sandstone bedrock overlying older Carboniferous strata, with deep boreholes proving sedimentary rocks of the Warwickshire Group, Coal Measures, Millstone Grit and Craven Group at depth.

Two main north-flowing tributaries of the River Mersey drain the area: the River Gowy/Mill Brook in the western part of the area and Hornsmill/Peckmill Brook in the east.

Parts of the area have had a long history of industrial development, and this has left a legacy of Made Ground (associated with factories, railways and waste tips) and Worked Ground (associated with the Manchester Ship Canal and small excavations), with much of the area also landscaped with poorly-defined areas of levelled ground.

A schematic model (not to scale) showing the predicted natural superficial geology near Ince Marshes. The ground surface slopes from south to north.

Quaternary geology

The area is mantled by a variable thickness of Quaternary Deposits that are up to 60 m thick, although are absent beneath parts of Ince and Elton. The upper surface of bedrock has been deeply incised during the Quaternary, with thicker accumulations of Quaternary Deposits infilling a series of broadly north-trending Buried Channels. These follow the modern drainage trends of the River Gowy, Mill Brook and Hornsmill/Peckmill Brook.

Tidal Flats are present in the western, northern and eastern parts of the area and Alluvium is associated with the Mersey and Gowy rivers, Mill Brook and Hornsmill/Peckmill Brook. This typically comprises unconsolidated sand, silt and clay and may include lenses of Peat or organic-rich muds. Other post-glacial sediments that are present locally in the area include Peat and Blown Sand. Post-glacial deposits overlie a complex of glacial deposits that principally comprise Till (boulder clay), with lenses of Glaciofluvial Sand and Gravel and Glaciolacustrine Clay. The precise relationships between the glacial deposits are in places chaotic, varying laterally and vertically across short distances, making extrapolation difficult in areas where borehole data are sparse or absent.

Extract from the 3D model of Quaternary Deposits near Ince Marshes. Using the BGS Lithoframe software, the Quaternary geology of Ince Marshes can be viewed in different perspectives.

A detailed description of the Quaternary geology of the Ince Marshes area that is included in the 3D model referred to above is described in:
BURKE, H F, GOW, H V, CRIPPS, C, THORPE, S, HOUGH, E, HUGHES, L and HORABIN, C G. 2016. The 3D Quaternary geology of the area around Thornton, Cheshire. British Geological Survey report OR/16/056, 25pp.

A conceptual geological model for Quaternary processes and deposits is described in:
LEE, J R and HOUGH, E. 2017. A Conceptual Geological Model for investigating shallow sub-surface geology, Thornton-le-Moors, Cheshire. British Geological Survey report OR/17/042, 43pp.

A 3D model of the Quaternary deposits is available as a Lithoframe dataset. This is available for download from the links below:

LithoFrame model 3D pdf LithoFrame Viewer
Ince Marshes, Cheshire Ince Marches 3D pdf Ince Marshes area Lithoframe model

Download the Lithoframe viewer.

Bedrock geology

Sherwood Sandstone formerly exposed at Stanlow Point on the south shore of the Mersey. BGS photographic reference number P207311

Geological maps along with data describing the Ince Marshes area, including UKOGL Exploration Seismic Data, boreholes and core materials are available to view on the BGS Geoindex Onshore. Bedrock in the area is formed by the Sherwood Sandstone Group. The upper part of the bedrock may have been weathered to an uncemented sand and gravel to depths of 5–10 m; this may be difficult to differentiate from the glacial sand and gravel deposits where the latter are in contact with bedrock. The Sherwood Sandstone Group typically comprises red and grey fine-to medium grained sandstone with rare pebbles. Deformation bands (zones of grainsize reduction formed in response to stress) may be developed locally.

General structure of the Ince Marshes area, based on interpretation of seismic reflection line SC-83-128V, illustrating the Ince Marshes horst structure defined by the Waverton Fault Zone to the west and Dungeon Banks Fault Zone to the east. FZ = Fault Zone.

Analysis of released 2D seismic reflection data indicates that the bedrock structure is characterised by a north-trending horst block that is 1-2 km wide in the Thornton area. The horst is defined by the Waverton Fault zone to the west, and the Dungeon Banks Fault zone to the east. Provings from deep boreholes sunk for hydrocarbons exploration give information on bedrock stratigraphy in the area. The Ince Marshes 1 borehole proves the succession on the horst, while the succession in the graben to the east is proved by Kemira 1 (summarised below).

Stratigraphy Bedrock geology: horst (as proved by the Ince Marshes 1 Borehole); depths quoted in m to base of unit. Bedrock geology: eastern graben (as proved by the Kemira 1 Borehole); depths quoted in m to base of unit.
Permo-Triassic 272 1042
Carboniferous Warwickshire Group 331 1221
Carboniferous Pennine Coal Measures Group 945 Terminal depth at 1438
Carboniferous Millstone Grit Group Terminal depth at 1577 Not proved

A petrophysical interpretation of the Ince Marshes 1 and Kemira 1 wells is described in:
HANNIS, S and GENT, C. 2017. Petrophysical interpretation of selected wells near Liverpool for the UK Geoenergy Observatories project. British Geological Survey report OR/17/037, 44pp. Contains:

  • Stratigraphic column of the geology proved by Kemira #1 Borehole, located in the graben to the east of the Dungeon Banks fault zone on page 13.
  • Stratigraphic column of the geology proved by Ince Marshes #1 Borehole, located on the horst block between the Dungeon Banks and Waverton fault zones on page 14.

An assessment of subsurface stress is described in:
FELLGETT, M W, KINGDON, A, WILLIAMS, J D O and GENT, C M A. 2017. State of stress across UK Regions. British Geological Survey report OR/17/048, 60 pp.

Contacts

Please contact Enquiries for more information about the UK Geoenergy Observatories.