Book review: A Field Guide to Fossils & Geology of the Isle of Wight by Megan Jacobs

Jon Trevelyan (UK)

There can be few places in Britain better suited to a geological field guide than the Isle of Wight. Its relatively small area contains an extraordinary range of rocks and fossils, while its eroding cliffs and beaches have produced discoveries ranging from ammonites and molluscs to plants, mammals and dinosaurs. Yet, this richness presents a problem for the newcomer. Where should you go? What rocks are you looking at? What might you reasonably expect to find? And, having found something, how do you identify it?

Megan Jacobs sets out to answer all of these questions in A Field Guide to Fossils & Geology of the Isle of Wight. At almost 300 pages, this is considerably more than a guide to a handful of fossil-collecting beaches. It combines an introduction to the geology of the island with practical advice on fossil collecting, descriptions of collecting locations and an extensive illustrated guide to the fossils themselves.

Perhaps the best way of judging the book is to imagine its likely readership. Suppose you are going to the Isle of Wight for a holiday. You have an interest in fossils and geology, but little specialist knowledge, and you intend to spend a couple of days fossil collecting. You want to understand something about the rocks you are seeing, find suitable places to search, and have some idea what you have found afterwards. This is precisely the reader for whom Jacobs’s book seems to have been written.

Therefore, this is not an academic monograph, nor does it pretend to be one. Instead, Jacobs has attempted the rather different task of taking a considerable amount of geological and palaeontological information and making it readily understandable to a non-specialist reader. She succeeds remarkably well. The book is nicely written, engaging and informative, and notably free from unnecessary jargon. Scientific concepts are explained rather than assumed, without giving the impression that the reader is being talked down to.

Jacobs is well placed to do this. Born and brought up on the Isle of Wight, she began collecting fossils there at an early age, before going on to study palaeontology academically. She is now a PhD student at the University of Portsmouth, where her research includes the Wessex Formation and its fauna. She will also already be known to some Deposits readers, having previously contributed to the magazine (see The forgotten women in UK geoscience, Prominent figures of the 1800s who gave rise to vertebrate palaeontology and Histology of a sauropod rib bone from the Wessex Formation, Hanover point, Isle of Wight). The combination of scientific training and long familiarity with the island is evident throughout the book.

Nor was Jacobs working in isolation. Professor Michael Benton contributes the foreword, while the acknowledgements reveal the considerable assistance she received from other eminent specialists. Professor Andy Gale helped by proofreading and fact-checking the text, assisting with figures and photography and providing scientific advice. Professor David Martill also spent considerable time proofreading the manuscript, in addition to providing support and encouragement. It is an impressive group of people to have behind a book intended primarily for the general reader.

The organisation of the book is one of its strengths. It begins with the history of Isle of Wight palaeontology, before introducing the geology itself, including the structure of the island and explanations of some of the processes responsible for the landscape we see today.

The geological succession is then explored in considerably more detail. Inevitably, the Cretaceous receives particular attention, with the Wealden, Lower Greensand and Chalk among the units discussed, but the younger Palaeogene and Quaternary geology is not neglected. Along the way, subjects ranging from landslipping and flint formation to the Chalk–Palaeogene unconformity are explained.

This geological background is important. Fossils are not treated merely as attractive objects waiting to be picked up from a beach. The reader is given enough information to understand why particular fossils occur where they do and how they relate to the rocks in which they are found. In this respect, the book successfully links three things that are sometimes treated separately: the geology, the collecting locality and the fossil itself.

The emphasis then becomes increasingly practical. A substantial section on fossil hunting deals with responsible collecting, safety, looking after specimens and, importantly for a beginner, the deceptively simple question: “What is a fossil?” This is followed by guidance to popular collecting locations around the island.

For someone actually intending to spend a day on the coast looking for fossils, this transition from geological explanation to practical fieldwork is particularly useful. The geology has given the reader a reason for going to a particular place; the field-guide element then helps them make sense of what they see when they get there.

However, Where the book becomes especially useful to the novice collector is after something interesting has actually been found. From page 141 onwards, a very substantial part of the book is devoted to fossil identification. The coverage includes the Wessex and Vectis formations, dinosaur footprints and foot casts, the Lower Greensand, Gault, Chalk and Upper Greensand, and the Palaeogene. Later sections extend the coverage to younger material, ancient humans, imported fossils and other finds, and minerals.

This is much more than a token selection of spectacular fossils. It is intended to help the reader identify the sorts of things that might actually be encountered, and that greatly increases the practical usefulness of the book.

Illustration is crucial to a field guide, and this is another area in which the book excels. It is lavishly illustrated in full colour, with lovely photographs of fossils and locations, as well as diagrams explaining aspects of the geology. The photography is not merely decorative. Seeing the rocks and landscapes being described helps the newcomer recognise them in the field, while good photographs of specimens are essential when the same reader later tries to identify what has been found.

The physical production of the book is similarly attractive. It is clearly laid out, extensively illustrated and substantial without becoming unwieldy, and its price also represents very good value for a specialist book containing so much colour photography and original material.

Perhaps the book’s greatest achievement is the way in which all these elements fit together. There are, of course, more technical works dealing with the geology and palaeontology of the Isle of Wight (see for example, Book review: The Isle of Wight (Geologists’ Association Guide No 60), by Andy Gale), just as there are simpler introductions for the casual visitor. Jacobs has found a useful position between the two. There is enough geology to explain the island properly and enough palaeontology to make the fossil-identification sections genuinely useful, but neither requires the reader to arrive armed with an extensive scientific vocabulary.

That makes the book particularly suitable for beginners and enthusiastic amateur collectors, although those with more experience are also likely to find plenty of interest. It could also be an excellent book for a younger reader whose enthusiasm for fossils is developing into a desire to understand the geology that gives them their context.

And so, we return to our hypothetical holidaymaker. If I were visiting the Isle of Wight with an interest in fossils, but without detailed knowledge of its geology, and intended to devote a couple of days to fossil collecting, this is exactly the sort of book I would want to take with me. It would tell me why the rocks and fossils are there, help me decide where to go, show me what to look for, and give me a reasonable chance of identifying what I found.

That is ultimately the fairest test of A Field Guide to Fossils & Geology of the Isle of Wight. It calls itself a field guide, and it works as one. But it also does considerably more. It encourages its readers not simply to collect fossils, but to understand the rocks from which they came and something of the vanished environments and organisms they represent.

For anyone planning to explore the geology and fossils of the Isle of Wight—particularly someone beginning to discover just how much there is to find – Megan Jacobs has produced a beautifully illustrated, informative and extremely useful companion.

A Field Guide to Fossils & Geology of the Isle of Wight, by Megan Jacobs (foreword by Professor Michael Benton), Medina Publishing Ltd, Cowes, Isle of Wight, (2026), paperback (330 pages), ISBN:‎ 978-1916866218