The author, David Evans, has brought together a comprehensive summary of the available data for till. The target audience for this book consists of researchers and specialists in glacial science and sedimentology. It covers a vast literature, including experimental and laboratory based reviews and assessments, in addition to comprehensive field studies. It is immediately evident that it comprises many hours of rewarding work from the author and colleagues. The book is built from international research in an attempt (among other things) to answer the simple but deceptively difficult-to-answer question: what exactly should be called ‘till’?
Each chapter begins with a helpful quote, from contemporary glacial scientists and even a former British Prime Minster. An early chapter outlining the history of till research is a welcome addition to the literature, providing a summary of research to date covering the adoption of the word 'till' as a geological term in 1863 through to the prevalence (and subsequent decline) of the alternative term, 'boulder clay'.
Although relatively short, an early discussion on the appropriate usage of ‘till’ helps shape and dictate the direction of subsequent chapters. An overview of the literature on glacial processes and suggested classifications is provided, including from the Glacial Working Group. The author builds upon previous recommendations of fellow glacial sedimentologists to develop a threefold classification system of till as generic terms, including: ‘glacitectonite’, ‘subglacial traction till’, and ‘melt-out till’. In establishing a simple and systematic nomenclature, future objective assessments of glacigenic deposits can be undertaken.
One personal quibble with the book relates to the editing – specifically, to the placement of references within sentences. In certain chapters, within the main text, the location of so many such references within the text adversely affected my flow as a reader. For example, including the references distended one sentence to cover more than four pages! This is, perhaps, a minor comment, and perhaps would not be so off-putting to readers more familiar with the subject matter. It does not detract from the overall scientific quality of the book.
If you are looking for a text that brings together a detailed review of the current state of ‘till science’, then this book is highly recommended - as a useful source of reference. It is hardly a light read, however.
Reviewed by Giles Bushell
TILL: A GLACIAL PROCESS SEDIMENTOLOGY by DAVID J A EVANS, 2017. Published by: Wiley-Blackwell cryosphere science series (HBK) ISBN: 978-1-118-65259-6 List Price: £95.00. W:
https://www.wiley.com/en-gb/Till:+A+Glacial+Process+Sedimentology-p-9781118652596