Now that we're all down with the new program and the novelty has worn off, though, there is interest and value in digging deeper again. The struggles of our scientific ancestors were not swept into irrelevance by plate tectonics, merely reframed. Mind Over Magma (Princeton University Press, 2003) is the first good look at one of those struggles: the historical development of igneous petrology, a thriving research field whose roots lie at the dawn of geology.
Since its beginnings in the 1700s, geology has undergone many waves of building and demolishing theories. These theories all had to deal with various strange rocks that are not recognizable as former sediments: lavas, granites, the dark and flinty stones called basalt. Indeed they were not all recognized as products of rock turned molten by intense subterranean heatas products of magmauntil the 1800s, when the well-documented argument between Neptunists and Plutonists was settled by evidence from the field and laboratory. But a curious blend of fire and waterof melting and dissolution within that melthas remained central to igneous petrology. The problem has benefited from insights on all sides.
Davis Young, professor of geology (now emeritus) at Calvin College, set out to write Mind Over Magma as an insider, a practitioner rather an academic historian. His reader needs to be just as dedicated to the subjectat the grad-student level at a minimumbut that reader will be delighted. The book fairly glows with Young's affectionate attention to the field's deep geekiness. It also is infused by his perspective that, in his words, "a grasp of the history of igneous petrology should encourage future petrologists to be less dogmatic about their own ideas." Without the right teachers or the experience that comes with long life, only history can grant that essential intellectual modesty.
Young traces the history of his field through several phases, a generation or so in length, in which an advance in theory or technique led to concentrated progress closely tied to ever more attentive fieldwork. We have the "primitive era" in which igneous rocks were named and classified in various systems; the "microscope era" powered by the study of thin sections and mineral optics; the "experimental era" of making magma in furnaces with major-element recipes; the "geochemical era" exploring isotopic and trace-element evidence; and the modern approach dominated by sophisticated models of magma chambers, the "fluid dynamical era." I find this practice-centric insider's approach more interesting and digestible, and more authoritative, than a cultural or historiographical account.
Each era's learning accreted onto, as well as eroded into, the knowledge from the previous eras. Each generation came up with new names and classifications of the rocks. Here Young does a signal service in tracing the origins and evolution of the rock names and terminology we rely on today, in all their profusion and confusion. He also treats some of the different approaches in nation- or language-centered scientific communities over the years. This work helps in better understanding the older literature through the prism of time.
Young sees Mind Over Magma as the skeleton or tree-trunk of a fuller history of igneous petrology. There are books still to be written about each of the major rock types, the igneous petrologists and the personalities, and the preoccupations of philosophers and historiographers. The value and beauty of Young's book is that it sets a firm framework for that elaboration based on what matters in the rocksat least as it appears from today's point in our ongoing journey. I plan to rely on it for the rest of my career.