The Carboniferous Timescale
In the two centuries since ‘Carboniferous’ was first used as a stratigraphic term, our knowledge of Carboniferous rocks has advanced immeasurably. In this volume, Lucas et al. have assembled an encyclopaedic review of the principal disciplines that contribute to a stable scale of reference for the Carboniferous Period and System. An historical account of Carboniferous timescales, and reviews of stratigraphic schemes for Russia and Argentina, are followed by seventeen single-discipline chapters. Many of the chapters are very comprehensive, for example, fusuline foraminifera get 170 pages. Too many specialisms are represented here for individual assessment by a single reviewer, but the work involved was clearly monumental; the brachiopod chapter won’t be unique in having been ‘hard (but very satisfying) to complete’, in the words of its authors.
Since 1976, there has been an international process to fix major chronostratigraphic boundaries at Global Stratigraphic Sections and Points (GSSPs). The GSSP process demands considerable data collection and assimilation; the comprehensive nature of this book epitomises these efforts. While the ultimate objective is a robust scale of reference, the process works both ways: it provides a focus for the compilation of regional and international, single and multi-disciplinary scales of events, giving the foundation for defining boundary stratotypes. This project is well into its fifth decade, yet four of the seven stage-level Carboniferous GSSPs remain undefined. This book addresses the hurdles, including inter-discipline correlation and integration, and more data leading inevitably to exponential increases in the possible permutations between datasets. The selection of boundary-defining events tends to favour one discipline over others; the bivalve chapter notes that a worldwide wealth of bivalve data is largely unused – why so, when modern computing power enables impartial use of very large datasets?
To this reviewer, The Carboniferous Timescale represents a plethora of high-quality data and the search for a method for coping with it. It also represents a moving target – various authors stress the unfinished state of their studies. I’m not the first to urge the use of optimisation methods for seeking best-fit stacks from all available biostratigraphic, physical, and chemical data, alongside the conventional GSSP procedures. Optimisation could provide constantly updatable syntheses, likely leading to new ideas and improved temporal resolution. Meanwhile, Spencer Lucas is to be congratulated on the compilation of these volumes, which will provide an essential source for Carboniferous stratigraphic and timescale studies for many years to come.
Reviewed by David Smith
BY: S.G. Lucas, J.W. Schneider, X. Wang, & S. Nikolaeva (eds.) (2022). Geological Society of London Special Publication No 512 (2 vols). 1016 pp. (hbk)
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