Oxfordshire Rock Types: Chipping Norton
Chipping Norton Formation
Some Key Words
containing calcium carbonate
a sedimentary structure developed by the migration of small ripples, sand waves, tidal-channel large-scale ripples, or dunes and consists of sets of beds that are inclined to the main horizontal bedding planes.
a soft coal, usually dark brown, often having a distinct woodlike texture, and intermediate in density and carbon content between peat and bituminous coal.
consisting of or containing small, spherical or sub-spherical ooids.
This limestone ranges in thickness from 0-12 m (12.7 m at Chipping Norton). Lithologically it is a hard, splintery, buff/brown rock. Texturally it may be described as fine to medium-grained ooidal and coated peloidal grainstone. Fine burrows, medium to coarse-grained shell detritus, flakes of greenish grey mudstone, dark lignite and minor amounts of fine-grained sand elude to its near shore, marine depositional environment. The Chipping Norton Limestone can be described as a thick-bedded and cross-bedded, weathering to flaggy or platy. Thin shell-detrital and ooidal marl and mudstone intercalations in places.
Vertically, the Chipping Norton limestone has a lower boundary which is conformable/non-sequential with the Clypeus Grit member. Locally a mudstone bed (Roundhill Clay) up to c.1 m thick occurs at the base. The upper boundary is with the Sharp's Hill Formation. Laterally the formation passes into the Horsehay Sand Formation to the north east.
North Oxfordshire Cotswolds.
Oxfordshire County Council Quarry, Chipping Norton.
Ditchley Quarry aka Town Quarry, Charlbury (SP 370 200)