South-west England Chalk Group Lithostratigraphy: Jukes-Browne & Hill, 1903, 1904 - Arenaceous Beds

From Earthwise
Jump to navigation Jump to search

Jukes-Browne & Hill (1903) used the term Arenaceous Beds to describe the lowest calcarenitic chalk seen on the coast at Hooken Cliffs [SY 219 881] and Beer Head [SY 2268 8790], and inland around Wilmington[SY 208 999]. These beds are thickest at Wilmington (c. 12 m), and thin to c. 7 m at Hooken Cliffs, and then to a metre or less elsewhere (Jukes-Browne & Hill, 1903). The beds comprise coarse-grained quartzitic and glauconitic, locally nodular and poorly consolidated, calcareous sandstone, typically richly fossiliferous, particularly at Wilmington, where echinoids, bivalves and brachiopods are common (Jukes-Browne & Hill, 1903, p. 129). In coastal sections, the Arenaceous Beds were subdivided , in ascending order, into A1 and A2.

Macrofossil Biozonation: Assigned by Jukes-Browne & Hill (1903) to the M. mantelli Zone, but in terms of modern biostratigraphical nomenclature, also including the M. dixoni Zone (Wright & Kennedy, 1984).

Correlation: see Correlation with other lithostratigraphical schemes for south-west England

see Correlation with other UK regions.

References[edit]

JUKES-BROWNE, A J & HILL, W.1903. The Cretaceous rocks of Britain. Vol. 2 - The Lower and Middle Chalk of England. Memoir of the Geological Survey of the United Kingdom.

WRIGHT, C W & KENNEDY, W J. 1984. The Ammonoidea of the Lower Chalk. Part I. Monograph of the Palaeontographical Society. London: 1-126, pls 1- 40 (Publ. No. 567, part of Vol. 137 for 1983).

See: Wilmington, A1, A2