Abstract
Caves are places that evoke a variety of emotions. Some people revile them as dark, dank places best avoided, as gateways to the underworld or simply places to be ignored – out of sight, out of mind. Others view them as places of wonder, full of beauty or as a playground tinged with the thrill of exploration. Humans have used caves over millennia, for shelter and as places of worship and ritual, to exploit raw materials and more recently for tourism and recreation. They are superb archives of palaeoenvironmental data, sheltered from the ravages of surface weathering and erosion, and at the same time providing home to a diverse range of animals. Karst aquifers are an important source of clean water. More recently, caves have attracted the interest of naturalists, archaeologists, geologists and geomorphologists, trying to better understand the caves and the deposits they contain and what this means for the wider environment. This book touches upon all of these topics.
The author, David Gillieson has decades of experience exploring and studying caves across Australia and southeast Asia as well as North America and Europe. He is an Honorary Professor with the School of Geography Earth and Atmospheric Sciences, University of Melbourne, Australia, and has previously held academic appointments at the Australian National University, University of New South Wales and James Cook University. He has written extensively on caves and karst, and was former Chair of the International Geographical Union Commission on Karst. This is the second edition of Caves: Processes, Development, and Management. The first edition was published in 1996, so this is a welcome, long overdue revision. Since that time, there have been significant advances in many aspects of cave and karst science, ranging from improvements in dating techniques and the use of speleothems as palaeoclimatic proxies, the use of computers to model karst groundwater and speleogenesis, to the recognition that rising thermal or artesian waters can generate significant and extensive hypogene cave systems.
The book opens with a brief introduction. The first section (Chapters 2–5) discusses the processes of cave formation and development, covering topics such as karst hydrology, the processes of rock dissolution and how caves form, a process known as speleogenesis. Each of these chapters concludes with a case study or type example to put the chapter into context, often based on the author’s personal experience. Chapter 1 is mostly about defining karst and caves, before discussing them as geomorphological and biological systems. Chapter 2 focusses on cave hydrology, defining the basic concepts and outlining techniques used to analyse karst drainage systems such as water tracing and hydrograph analysis, ending with a case example from the Mammoth Cave region in Kentucky. The nitty-gritty of how rock dissolves is covered in Chapter 4, covering not just limestone but also gypsum, halite, sandstone and granite and many different settings. Chapter 5 expands on this to discuss speleogenesis in all its guises, what influences how and where caves form, and how to recognise the various types and styles of cave development. The chapter covers not just classic epigenic caves, but also hypogene caves and pseudokarst including lava tubes.
The second section of the book (Chapters 6–9) deals with past processes and their products. As befits the topic, this covers a diverse array of subjects including speleothems and other cave minerals (Chapter 6) and cave sediments (Chapter 7). The various types of cave interior deposits, not least speleothems are highlighted, along with their modes of formation and deposition. Chapter 6 concludes with a section on the unusual mineralogy of the caves of the Nullarbor Plain in Australia, whilst Chapter 7 ends with a section on the cave sediments and environmental history at Zhoukoudian in China, where Homo erectus pekinensis was discovered. How these deposits are then analysed and interpreted are dealt with in the following chapters. Chapter 8 deals with the various ways of dating speleothems and cave sediments, a topic which has rapidly advanced since the first edition of the book, and which is fundamental to the use of speleothems as archives of past climate. This leads neatly to the next chapter which discusses how speleothems and cave sediments are used to decipher past environments and climates. This covers oxygen and carbon isotopes in speleothems, but also other proxy records such as trace elements, pollen and lipid biomarkers.
The third section of the book covers the use of caves by various organisms, past and present. Caves, particularly those in the tropics are home to countless creatures, some of whom are highly specialised to living in the dark. Many cave deposits are either formed or affected by biogenic activity. This is the subject of Chapter 10, which deals with cave ecology. As with other chapters, this covers a diverse range of topics, discussing the role of caves as a habitat and how life adapts to the cave environment from the very small microbiological scale, through to larger animals including bats. There is a great section on the recent outbreak of White Nose Syndrome which has devastated bat colonies in North America. One of the larger organisms that uses caves is of course humans, and this is covered in a chapter (Chapter 11) on cave archaeology. This covers the fossil record of early humans preserved in caves, through to the prehistoric use of caves, including as a canvas for artwork. The chapter ends with a section on the archaeology of Liang Bua Cave on the island of Flores in Indonesia, more famous as the site where Homo floresiensis, a diminutive hominin dubbed the Hobbit was discovered. The more recent use of caves by humans is dealt with by the next chapter on the historic uses of caves (Chapter 12), covering caves as shelters, refuges and sacred spaces and as a resource, both in terms of raw materials but also for tourism and recreation.
This leads to the final section of the book which reviews the changing approaches to managing caves, both the caves themselves and their wider karst environment and hydrogeological catchment. Chapter 13 focusses primarily on the management of the caves themselves, both as recreational and tourism venues, for example dealing with radon hazards, cave lighting and the impact of recreational caving. It concludes with a section on the management of the Gunung Mulu World Heritage Area in Sarawak, a National Park containing some of the largest caves in the World, including the spectacularly huge Deer Cave, home to around 3 million bats from over 30 species. The concepts and techniques of wider catchment management are the subject of Chapter 14, tackling subjects such as groundwater contamination, fire management, soil loss and other conservation challenges. The means of documenting caves including surveying, 3D scanning and photography are all covered in Chapter 15. This is a topic that is undergoing rapid development with the advent of digital cameras, portable laser scanners and hand-held mobile phones and laptops, technology that simply was not commonly available in 1996. The book concludes with a glossary of cave and karst terminology, further reading and an index.
One of the strengths of this book is the breadth of its coverage. Many topics are included that are simply not covered in most other cave and karst textbooks, or are dealt with as more specialised niche publications. This is particularly the case with the second half of the book dealing with the use of caves by both humans and animals and how the caves and karst environments can be managed appropriately. This will be of particular interest to the applied user, for example someone who has to deal with managing groundwater resources in a karst environment, or running a show-cave whilst not damaging the very thing the public comes to see, or even just a recreational caver wanting to know how to reduce the impact of their activities. These topics are addressed comprehensively and impressively.
What is less well done is the opening two sections of the book. It is very evident that this is a second edition with a significant time gap since it was first published. Whilst many advances and major developments in the field since 1996 (publication date of the first edition) are covered, many of the refences and examples in the second edition still hark back to work done in the 1970s and 1980s. Other publications such as ‘Cave Geology’ by Art Palmer (Cave Books, ISBN: 9780939748662) offer a much more comprehensive and up-to-date treatment of cave formation and karst hydrogeology. That said, the basics are well covered, although some errors creep in, for example the statement that ‘chalk is a mechanically weak rock and conduits may not survive’ when it is abundantly clear that caves and conduits, albeit small can develop in the chalk and persist over long timescales. Most, although not all of the figures are clear and useful. Some of the photographs used were taken during caving expeditions several decades ago. Whilst at the cutting edge of photography at the time, these now appear rather dated and of poor quality given the recent huge advances in cave photography as outlined in Chapter 15.
One refreshing aspect of this book is the use of examples from the southern hemisphere. Most cave and karst text books have a strong North American or European bias, despite some of the most extensive areas of karst occurring in China and southeast Asia. Gillieson has gone some way to rectifying this, referring to many cave studies and examples from Australia, New Zealand, China and other parts of southeast Asia. The result is a much more rounded and balanced overview of world cave and karst science. Notwithstanding the minor shortcomings, this is still a good book for anyone who is interested in caves and karst, and especially for those involved in the management and protection of caves and karst environments. It serves as a useful and very comprehensive introduction to the subject.