Lithology:

A pale grey/brown to off-white, medium to fine-grained, quartzose.  In other places is can appear unbedded, weakly-bedded or cross-bedded; cemented into a calcareous (or weakly ferruginous) sandstone; with occasional thin, dark grey mudstone and siltstone beds. Rootlets and lignitic debris common. Shelly material is rare.

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Lithogenetic description:

Marginal marine or deltaic conditions depositing mainly sand.

 

Landform description:

Generally forms hollows between upstanding harder limestone or ironstone units. In some places  the hollows may be formed by this unit coated with mudstone of the Sharp’s Hill Formation.

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Definition of upper boundary:

An upward change into mudstone, calcareous mudstone and limestone beds of Sharp's Hill Formation; or the ooidal and shell detrital limestones of Taynton Limestone Formation. Boundary non-sequential. May be marked by an eroded or leached and rootlet-bearing top.

 

Definition of lower boundary:

Change up from (lithologically similar) sand and sandstone beds with marine shelly fauna, but also including ooidal and shell-detrital limestones of Northampton Sand Formation (Inferior Oolite Group), where present, or mudstone beds of Whitby Mudstone Formation (Lias Group), into barren sand-dominated beds. Boundary on Northampton Sand Formation though non- sequential, is usually apparently conformable or even gradational (probably as a result of weathering effects), but locally may be disconformable or channelled (Horton et al., 1987, p. 56).

 

Thickness:

Up to 7 m.

 

Reference Site:

Horsehay Quarry, Duns Tew, Nr. Chipping Norton Oxfordshire.  (SP 456 273)  

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Spatial Distribution:

North-east Oxfordshire:  Sibford Gower, Hook Norton and Tackley [Horton, 1977, fig. 4], where it passes south-west (on BGS 1:50 000 sheet 218) into the Chipping Norton Limestone Formation