The aim of the review was to cover the whole range of stratigraphy from Great Britain, describing in particular the most important stratotype sections, key stratigraphical contacts and the principal lithologies and biofacies. The introduction to Cambrian and Ordovician stratigraphy is short. The main components of the Cambrian and Ordovician biotas are noted as brachiopods, trilobites and graptolites. Microfossils are also noted to occur in this interval. As an example, ‘acritarchs and chitinozoans are important in certain parts of the geological column’ is a notable quote. The authors could perhaps have said ‘acritarchs are likely to be found in abundance in the marine sediments exposed at most localities in the Cambrian and Ordovician, and that future research could be directed to fully investigate their full biostratigraphical and palaeoenvironmental potential.’
For each of the 28 Cambrian and 99 Ordovician localities the information is mostly taken from published sources. The text is clear, and reads much like recent BGS memoirs – a sound outline, but lacking some important taxonomic details. The diagrams, mostly redrawn from publications, are clear and easy to use. The reproduction quality of the black and white locality photographs is poor. For each of the areas covered, the diagram of the stratigraphical coverage of the sites is given, which is very helpful. It also highlights the lack of site coverage for some intervals. A quick look at the index shows few references to acritarchs, chitinozoans and conodonts, though some references in the text are not indexed. No mention is made of the excellent preservation and low geothermal alteration of the palynomorphs in the Tremadoc Shineton Shales and Caradoc of Shropshire when compared to the high organic geothermal alteration in North Wales., There are a number of additional potential GCR sites that could have been included. These should perhaps include Skiag Bridge in northwest Scotland for the early Cambrian, Mattocks Hill in Shropshire for the Shineton Shales sedimentology, and additional road and river sections in the type Caradoc area for sedimentology, acritarchs, chitinozoans and spores.
The sites are described in geographical and stratigraphical order: Cambrian of North Wales, Harlech Dome and Arfon area; Cambrian of South Wales: St. David’s Area; Cambrian rocks of England; Tremadoc Series in Wales and England; Arenig to Ashgill in South Wales; Arenig to Ashgill of North Wales; Arenig to Caradoc of Shropshire; Arenig to Ashgill of northern England; Scotland: Cambrian and Ordovician of the Hebridean Terrane; Scotland: Cambrian and Ordovician of the Grampian Terrane and Highland Border Terrane; Scotland: Ordovician of the Midland Valley Terrane; Scotland: Ordovician of the Southern Uplands Terrane. A list of the sites are on the website.
For those undertaking research on Cambrian and Ordovician sections, the volume brings together much of the published data on the sites described, and provides a list of references where further details may be found. At £70.00, this volume is a valuable research reference book for workers on the Lower Palaeozoic of Great Britain.
Ken J. Dorning
University of Sheffield, UK