Devil in the Mountain: A Search for the Origin of the Andes [Paperback]

Research geologists rarely spend much energy synthesizing and making their work available to the general public, to both party's loss. But Lamb does that here, giving an accessible overview of the Central Andes that will be of interest to the traveller as well as the geologist. His writing is clear and filled with personal anecdotes that are well-integrated into his story. The combination of travelogue, the tale of a young man building a team and a career, and explanation of modern mountain-building concepts is an unusual way to present the material, but it provides spice and should motivate a wide range of readers to keep turning the pages. It is richly illustrated with detailed illustrations and maps of the highest quality, I can't thank the author and publisher enough for their care in this regard. I have a few quibbles, though. Lamb doesn't note the fact that lithosphere of increasingly young age has been subducted beneath S. America through the Cenozoic, making subduction increasingly difficult and converting an extensional 'Mariana-type' convergent margin into the present 'Andean-type' compressional margin. He doesn't mention the presence and role of 'flat-slab' segments of the S. American subduction zone (and their possible role in raising the Andes). He doesn't consider the importance of trade winds being blocked by Eastern Andes for producing the deserts and empty trenches of the central Andes. But these weaknesses are amply compensated for by the overall product, an ambitious, well-edited, and compelling overview of a great mountain range.

"Tourists do not normally go to the places geologists want to visit." These are the words of a geologist, Simon Lamb, who has done years of fieldwork in Bolivia (which tourists go to Bolivia for any reason?) to hunt for an answer to a basic question: How do high mountain ranges form? The question seems so basic to non-geologists; after all, to the rest of us, the mountains just seem always to have been there, and they don't change a bit that we can see. Geologists, however, look at the world in a different way; even the ancient Andes mountains participate in a life and death cycle, and according to Lamb, they are "almost living creatures, and... their life stories are deeply felt by the rest of the planet." He has wonderfully succeeded in conveying a geologist's view of the world in _Devil in the Mountain: A Search for the Origin of the Andes_ (Princeton University Press), which although it looks at his Bolivian exploits in particular, is a fine primer for anyone who wants to learn some geological basics.

The revolutionary ideas of plate tectonics were all well accepted in the 1980s, when Lamb started his career. Though plate tectonics explained much, it didn't answer specifics about the Andes. What made them so high, for instance, and how is it that unlike other mountain ranges, they have a bent rather than straight or sinuous appearance on the map? Through extensive travel within Bolivia in a battered land cruiser, he and his colleagues and students developed a picture of the mountains over the past 65 million years. The picture of the rise of the mountains can be put into order "using not much more than a hammer and a compass", but putting dates on the events cannot be done with simple equipment. Lamb explains potassium / argon dating, the search for tracks of particles of uranium decay within zircon, the process of crushing rocks to determine their strength, sampling helium from volcanoes, and the use of the Global Positioning System for measurements within a few millimeters. Though these technical matters occupy much of the book, it is mostly a chronological memoir about how Lamb came to his current understanding of the formation of the Andes. As such, it is full of adventures, some having to do with unscrupulous natives, or dodgy bureaucrats, or cantankerous machines, told here with good humor.

Using the Andes as a working example, Lamb is able to jam his book full of interesting accounts of finding out how the mountains grew, and contrast them with the Alps, Rockies, or the ancient hills of Britain. The great engine of the inner Earth, powered by gravity and radioactive heat, is revealed to be strange, unlike anything we have to deal with here on the surface, but comprehensible. Lamb shows that the knowledge is vital for many reasons, not the least of which is that the Andes are a force strongly contributing to world weather. The Andes make possible, for instance, the rainforests of the Amazon, and over long geological history probably played a role in the spread of savannah in Africa, which may have changed primate evolution. The forces of such changes are still at work, and are excitingly explained in Lamb's agreeable combination of pure science and field memoir.

I bought this book because, as a geologist myself, I am getting interested in the dynamics and tectonic controls of fluvial "megafans" developed along the Andean chain. I thought this little work, straddling the border between a popularization of geotectonics and personal travel diaries, could help me break the ice with the geological context of Bolivia and surrounds... Spot on!
Lamb did a great job, whether you look at it from the technical point of view or from a layman's perspective. Of course the geological insights to gain here are just very basic, they are meant to inform the uninitiated, but the style and the motivation with which a geologist's thoughts are reported, well, they kind of make me proud of my research... (Which I already was anyway!) Maybe the links between orogeny in the Andes and global climatic interactions are way too simplistically explained, and some people might get tricked into believing the climate system is really that! easy and predictable... I doubt... But that's a kind of problem you run into when trying to simplify to the extreme, opening a door for the newbies. No fuss then...
If you want to gain a feeling of what geological fieldwork feels like, if you'd like to learn something really cool on how rocks and mountains develop and behave through time on this planet, and maybe if you could use some insider's advice on how to get about in Bolivia (you never know where research might take you some day eh...), then this is a fun, quick, informative and emotionally rewarding read. I guess we're still far from really having understood the whole story about the Andes, but as Lamb shows, from his very personal point of view, sometimes the journey can be more important than reaching your destination too quickly... It all has to grow inside of you...