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THE CARBONIFEROUS STRATIGRAPHY OF THE ROMAN WALL DISTRICT IN WESTERN NORTHUMBERLAND

1959; Zoological Society of London; Volume: 32; Issue: 1 Linguagem: Inglês

10.1144/pygs.32.1.83

2041-4811

Gareth Johnson,

Geological and Geochemical Analysis

Summary The stratigraphy of part of the Yoredale Bernician Limestone Group succession of western Northumberland is described. The western extremity of the area concerned lies at the eastern margin of the Brampton district (Trotter and Hollingworth, 1932). During the present re-survey a series of 11 Yoredale Cyclothems, some of them multiple, have been traced 17 miles from the margin of the Brampton district eastwards to the River North Tyne. The succession changes considerably when traced from west to east across this area owing to variations in lithology and the splitting of some of the limestone horizons. The stratigraphical sequence in the eastern part of the area is similar to that in north Northumberland, and the Oxford Limestone, an important marker band in north and central Northumberland, has been recognized in the North Tyne region. The Yoredale Cyclothems of western Northumberland are in detail different from those of other regions. A series of minor rhythms is normally present towards the top of each cyclothem and a pyritic shale phase, sometimes with goniatites, occurs in the marine shales. An unusual reef-limestone facies is present in association with two of the limestones. Faunal bands are of use in lateral correlation of the succession and zonal fossils confirm that the sequence ranges from upper Viséan to lower Namurian. A faunal change occurs below the Viséan-Namurian boundary where there is also a lithological change.