A feature of the

geology of England The geology of England is mainly sedimentary. The youngest rocks are in the south east around London, progressing in age in a north westerly direction.

, the Stafford Basin extends beneath much of the

Midlands The Midlands (also referred to as Central England) are a part of England that broadly correspond to the Kingdom of Mercia of the Early Middle Ages, bordered by Wales, Northern England and Southern England. The Midlands were important in the Ind ...

county of

Staffordshire Staffordshire (; postal abbreviation Staffs.) is a landlocked county in the West Midlands region of England. It borders Cheshire to the northwest, Derbyshire and Leicestershire to the east, Warwickshire to the southeast, the West Midlands Cou ...

. It is a depositional basin which was initiated during the

Permian The Permian ( ) is a geologic period and stratigraphic system which spans 47 million years from the end of the Carboniferous Period million years ago (Mya), to the beginning of the Triassic Period 251.9 Mya. It is the last period of the Paleoz ...

period and continued to receive

sediment Sediment is a naturally occurring material that is broken down by processes of weathering and erosion, and is subsequently transported by the action of wind, water, or ice or by the force of gravity acting on the particles. For example, sand an ...

during the

Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...

period and probably thereafter. Part of a more extensive set of linked basins, it connects with the

Cheshire Basin The Cheshire Basin is a late Palaeozoic and Mesozoic sedimentary basin extending under most of the county of Cheshire in northwest England. It extends northwards into the Manchester area and south into Shropshire. The basin possesses something of ...

to the northwest, the

Worcester Basin The Worcester Basin or Worcester Graben is a sedimentary basin in central England, filled with mainly Permian and Triassic rocks. It trends roughly north-south and lies between the East Malverns Fault in the west and the Inkberrow Fault in the eas ...

via the Bratch Graben to the south and the Needwood Basin to the east. It is flanked in part to the west by the

Coalbrookdale Coalfield The Coalbrookdale Coalfield is a coalfield in Shropshire in the English Midlands. It extends from Broseley in the south, northwards to the Boundary Fault which runs northeastwards from the vicinity of The Wrekin past Lilleshall. The former coa ...

and to the east by the South Staffordshire Coalfield. The sedimentary sequence, principally

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

s and

mudstone Mudstone, a type of mudrock, is a fine-grained sedimentary rock whose original constituents were clays or muds. Mudstone is distinguished from '' shale'' by its lack of fissility (parallel layering).Blatt, H., and R.J. Tracy, 1996, ''Petrology. ...

s, within the basin is continuous with that of the adjoining basins in the rift complex. Deposition of the Chester Formation (formerly Chester Pebble Beds) for example is ascribed to a river flowing north from the Worcester Basin through the Stafford Basin and on into the Cheshire and East Irish Sea basins during the early Triassic. In contrast the Bridgnorth Sandstone Formation of this area is of aeolian origin, the equivalent of the Collyhurst Sandstone of the Cheshire Basin. The known Permo-Triassic stratigraphic sequence overlying

Warwickshire Group The Warwickshire Group is a lithostratigraphic unit of rock strata defined within the British Carboniferous system. Within the Pennine Basin it overlies (i.e. postdates) the Coal Measures Group and is deemed to be of late Westphalian and St ...

strata is thus (uppermost, youngest at top): *

Mercia Mudstone Group The Mercia Mudstone Group is an early Triassic lithostratigraphic group (a sequence of rock strata) which is widespread in Britain, especially in the English Midlands – the name is derived from the ancient kingdom of Mercia which corresponds to t ...

Sherwood Sandstone Group The Sherwood Sandstone Group is a Triassic lithostratigraphic group (a sequence of rock strata) which is widespread in Britain, especially in the English Midlands. The name is derived from Sherwood Forest in Nottinghamshire which is underlain by r ...

**Helsby Sandstone Formation (=Bromsgrove Sandstone Formation) (

Anisian In the geologic timescale, the Anisian is the lower stage or earliest age of the Middle Triassic series or epoch and lasted from million years ago until million years ago. The Anisian Age succeeds the Olenekian Age (part of the Lower Triassic Ep ...

, Triassic) **---''unconformity''--- **Wildmoor Sandstone Formation (

Early Triassic The Early Triassic is the first of three epochs of the Triassic Period of the geologic timescale. It spans the time between Ma and Ma (million years ago). Rocks from this epoch are collectively known as the Lower Triassic Series, which is a un ...

Epoch) **Chester Formation (=Kidderminster Formation, Chester Pebble Beds) (

Olenekian In the geologic timescale, the Olenekian is an age in the Early Triassic epoch; in chronostratigraphy, it is a stage in the Lower Triassic series. It spans the time between Ma and Ma (million years ago). The Olenekian is sometimes divided into ...

,Triassic) **---''unconformity''--- **Bridgnorth Sandstone Formation (

Cisuralian The Cisuralian is the first Series (stratigraphy), series/Epoch (geology), epoch of the Permian. The Cisuralian was preceded by the Pennsylvanian (geology), Pennsylvanian and followed by the Guadalupian. The Cisuralian Epoch is named after the w ...

Epoch, Permian) **---''unconformity''---

References

{{Reflist Sedimentary basins of Europe Geology of Staffordshire Geography of Staffordshire

See also

References