A Quantitative Study of a Sequence of Coal‐bearing Cycles in the Namurian of Central Scotland, 2

Abstract

SUMMARY The quantitative relationships between stratigraphical variables from a succession of coal‐bearing cycles deposited in a subsiding basin have been investigated using principal component‐ and factor analysis, in an attempt to reveal simple relationships undetected by conventional qualitative methods. Knowledge of such relationships will undoubtedly be useful in future computer simulation studies of cyclical sedimentation. Principal component analysis and factor analysis yield similar results, which confirm and amplify those of the trend surface analysis described in Read and Dean (1967).

Quantitative relationships between numbers of fluvial cycles, bulk lithological composition and net subsidence in a Scottish Namurian basin

“…Firstly, the horizons which show definite evidence of colonization by vegetation have been counted in each section ; each vegetation horizon needed to be separated from those above or below by at least 0.3 m of sediments without any trace of root disturbance before it could be counted. This definition has previously been used by Duff & Walton (1964) and Read & Dean (1967, 1968 to define cycles in deltaic successions. It can equally well be applied to fluvial successions in which overbank deposits have been colonised by vegetation (Read &Dean, 1976).…”

“…The differentially subsiding Kincardine Basin east of Stirling within the Midland Valley of Scotland is highly suitable for this type of study because, firstly, a number of readily recognisable marker horizons allow successive stratigraphical intervals within the Namurian to be isolated and, secondly, a large number of continuously cored boreholes, scattered fairly evenly over the basin, provide representative sample-sections through each interval. Suitable background knowledge is also provided by a series of earlier studies of deltaic intervals in the same basin (Read, 1961(Read, , 1969b(Read, , 1976Read & Dean, 1967, 1968; Read, Dean & Cole, 1971), which have demonstrated the effects on sedimentation of structural elements in the basement and of persistent river channels which entered the basin. These studies have also helped the authors to select, adapt, and refine a series of quantitative and computer techniques which can be applied to basin analysis.…”

Coal correlation and intrabasinal differential subsidence — A case study from the Barakar Formation of Talchir Gondwana Basin, Orissa

“…In many instances, this has been attributed to autocyclic mechanism by way of intrabasinal differential subsidence. Nemec (1988) devised the method of quantification of intrabasinal differential subsidence by correlation of coal seams and successfully applied it to the South Wales and Intra-Sudetic basins (Read and Dean, 1967, 1968, 1976Johnson and Cook, 1973;Casshyap, 1975). In the present study, the same method has been applied to the Barakar Formation of the Talchir Gondwana basin.…”

“…Though these conditions prevail in an array of depositional environments, basin tectonism plays a key role in controlling the local base level and extent of peat forming mires. Significant statistical relationships between the number and thickness of coal cycles and net local subsidence of the basin floor have been demonstrated for various coal basins (Duff and Walton, 1962;Duff, 1967;Read and Dean, 1967, 1968, 1976, Johnson and Cook, 1973Casshyap, 1975 etc). Hota and Pandya (2002) and Hota and Sahoo (2009) have also established similar relationships for the Barakar and Karharbari Formations of the Talchir Gondwana basin respectively.…”

Lithofacies analysis and paleogeography of Bochumer Formation (Westfal A 2), Rufargebiet

“…In recent years, several studies have been made in which interrelationship between total thickness of strata and certain stratigraphic variables in the coalbearing sequences have been quantitatively investigated and possible underlying geological controls inferred (DvFF & WALTON, 1962MERRIAM & SNEATH, 1967;READ & DEAN, 1967, 1968. The three subdivisions of the Boehumer Formation have been investigated in a similar way, and relatively simple statistical method, namely, the ealeulation of product-moment correlation coefficients and linear regression lines (see KaUMBEIN & GRAYBILL, 1965, p. 284;SPmCEL, 1972, pp.…”