Abstract The Channeled Scabland of east-central Washington comprises a complex of anastomosing fluvial channels that were eroded by Pleistocene megaflooding into the basalt bedrock and overlying sediments of the Columbia Plateau and Columbia Basin regions of eastern Washington State, U.S.A. The cataclysmic flooding produced huge coulees (dry river courses), cataracts, streamlined loess hills, rock basins, butte-and-basin scabland, potholes, inner channels, broad gravel deposits, and immense gravel bars. Giant current ripples (fluvial dunes) developed in the coarse gravel bedload. In the 1920s, J Harlen Bretz established the cataclysmic flooding origin for the Channeled Scabland, and Joseph Thomas Pardee subsequently demonstrated that the megaflooding derived from the margins of the Cordilleran Ice Sheet, notably from ice-dammed glacial Lake Missoula, which had formed in western Montana and northern Idaho. More recent research, to be discussed on this field trip, has revealed the complexity of megaflooding and the details of its history. To understand the scabland one has to throw away textbook treatments of river work. —J. Hoover Mackin, as quoted in Bretz et al. (1956, p. 960)

The hypotheses of historical natural science are typically concerned with long past, singular events and processes, e.g., what caused the end-Cretaceous mass extinction. Evidence for such occurrences is acquired through field studies in the messy, uncontrollable world of nature. Because hypotheses about the remote past cannot be directly tested in the classical manner of experimental science, historical science is sometimes judged inferior. Building on earlier work, this essay explains the motivation for such arguments and why they are fundamentally mistaken. Traditional versions of the scientific method (inductivism and falsificationism) are based upon a deeply flawed, one-size-fits-all, logical analysis of the evaluative relation between hypothesis and observation. The distinctive methodologies of historical and experimental science, however, reflect pervasive causal differences in their evidential situations. The evidential reasoning of historical scientists is founded upon the principle of the common cause, which asserts that seemingly improbable associations among present-day traces of the past are best explained in terms of a common cause. The truth of the principle of the common cause rests upon a physically pervasive, time asymmetry of causation: In a nutshell, the present contains records of the past but not of the future. Viewed in this light historical scientists actually have an evidential advantage over classical experimentalists.

This chapter engages critically with Carol Cleland's recent work in the philosophy of historical science. Much of the practice of historical geology fits her description of the methodology of “prototypical historical science” quite well. However, there are also important kinds of historical scientific research that do not involve what she calls the search for the smoking gun. Moreover, Cleland's claim that prediction is not a major factor in historical natural science depends on taking an overly restrictive view of what counts as a prediction. Finally, Cleland's approach, which emphasizes methodology, is just one possible way of thinking about the difference between historical and nonhistorical science. Rather than focusing on the “how” of historical science, one can also focus on the “what” of historical science—on the nature of the processes and events that historical geologists study.

The issue of reductionism in geology has not yet been solved. The standard approach regards geology as a derived science, and therefore most modern philosophers are not particularly interested in it. On the other hand, in recent decades, interest in the philosophy of geology has grown, and growing numbers of modern philosophers oppose this approach. Some claim that geology and physics cannot be joined according to Nagel's reduction model, while others claim that geology is an autonomous historical interpretative science. My argument in this chapter is that there is a geological principle that meets the requirements of Nagel's reduction model, thereby enabling geology to function as an analytical science, deriving from the basic laws of physics, on the one hand, while also functioning as a geohistorical science, on the other. My argument is based on a logical-conceptual analysis of the uniformity principle in geology, and on the exposition of its close link to the second law of thermodynamics.

By means of numerous examples, this paper traces the early history of “geomaps” from the Renaissance to the early decades of the nineteenth century, considering in general terms the purposes for which the maps were compiled or the interests of the mapmakers. It is shown that a distinct change of style occurred approximately in the period from ca. A.D. 1760 to 1770, when maps changed from being pictorial (in various different ways) to diagrammatic. Following some early Italian work, the initial development of geomapping occurred particularly in the German-speaking parts of Central Europe and was chiefly associated with the work of Georg-Christian Füchsel and especially Abraham Gottlob Werner, along with his colleagues and former students. Such work was undertaken for economic reasons and was largely divorced from Werner's Neptunist doctrines. These maps showed the areal distributions of rocks of different types, and some showed the locations of mines and economically important minerals. By 1784, the whole of France was systematically mapped, but for the most part only showing the locations of economically important materials. These French and German maps did not convey any sense of time and were “positivistic” in character. In Britain, some Wernerian-style mapping was done, but this was overshadowed by the “biostratigraphical” mapping of William Smith, which started from economic concerns but eventually developed into an “end in itself” as he sought to produce a map for the whole of England and Wales and parts of Scotland. Smith's “pupil” John Farey produced maps of Derbyshire of extraordinary accuracy, as early as the first decade of the nineteenth century. The work of Alexandre Brongniart and Georges Cuvier focused on the Paris Basin and was (like Smith's work) based on the use of fossils, but it also showed an interest in the “conditions of existence” that obtained when the strata were deposited. Their work has been described and accepted as “geohistorical” and “properly geological,” whereas the earlier Wernerian maps were lithological in character, and initially the time dimension only appeared in them (to a small extent) with the work of Leopold von Buch. Attention is given to the question of the differences (if any) between geognostic and geological maps, and it is suggested that the conceptual differences were not fundamental. The category of “protogeological map” has been suggested, but its referent is not crystal clear. What is seen in the field is different from what appears in geological maps, which are forms of diagrams and need to be interpreted before use. Suggestions are made as to why geomaps appeared as and when they did. The role of the Industrial Revolution in leading to their production and development appears to be fundamental. Maps of special interest reproduced here are an anonymous one of Hel(i)goland, which is the first known to the author that delineates the boundaries between named lithological units; Georg-Christian Füchsel's remarkable map of Thuringia, here first published with color added; the strange and rather little-known colored manuscript map of Saxony by Christian Lommer; Werner's unpublished manuscript geognostic map of Saxony (1811); and John Farey's outstanding map of a part of Derbyshire. Various other little-known maps are also reproduced, as well as the “popular” ones of Johann Friedrich Wilhelm von Charpentier, William Smith, and Brongniart and Cuvier.

The practice of geologic mapping is undergoing conceptual and methodological transformation. Profound changes in digital technology in the past 10 yr have potential to impact all aspects of geologic mapping. The future of geologic mapping as a relevant scientific enterprise depends on widespread adoption of new technology and ideas about the collection, meaning, and utility of geologic map data. It is critical that the geologic community redefine the primary elements of the traditional paper geologic map and improve the integration of the practice of making maps in the field and office with the new ways to record, manage, share, and visualize their underlying data. A modern digital geologic mapping model will enhance scientific discovery, meet elevated expectations of modern geologic map users, and accommodate inevitable future changes in technology.

As humans become increasingly dominant agents of geologic change, prediction of the reaction of natural systems to human intervention and of the performance of geoengineered structures assumes increasing importance. To help clarify the role of geological prediction in an anthropic world, we examine the end-member cases of prediction in natural geologic systems and engineered systems. The behavior of natural geologic systems tends to be less reliably predictable than the behavior of engineered systems. Engineered systems are designed, and their behavior is predictable in terms of the function and interaction of their parts . Geologic systems, although undesigned, also have parts. Natural analogs of engineered parts are the emergent structures arising from nonlinear interactions between small-scale constituents. The behavior of natural systems at a given scale follows directly from the dynamics of their parts as defined at similar scales; it is argued that application of same-scale dynamics, or scale matching, provides the best basis for prediction in such systems. Mathematical models of natural systems are also likely to be most effective for prediction when applied at scales matched to the scales of the phenomenon of interest. There are also systems that are intermediate between natural systems and engineered systems. A “peri-engineering” transition zone governed by large-scale interactions is always present between the parts of the engineered structure and the parts of the surrounding natural environment. This contact region between engineered structure and the natural environment is often partially engineered to improve predictability. The peri-engineering halo is only partly subject to human design, and consequently it is often a region of reduced predictability and increased probability of malfunction or failure compared to the engineered system itself.

The enormous and growing scale of human intervention in coastal processes is driven by a short-sighted societal desire to protect property in the face of shoreline recession. Underpinning this effort in both the design of engineering interventions and the amelioration of their impacts is the application of numerical models that purport to simulate and predict coastal processes. Coasts are complex systems in which (1) waves, currents, tides, and wind operate on a (2) finite or changing volume of sediment of specific character (3) within a particular geological context. Feedbacks exist within and between these three domains, and all are temporally and spatially variable. The simplifications and assumptions involved in reducing this complexity to equations and numerical models cause a deviation from reality such that models are unable to provide realistic predictions of coastal behavior. Nonetheless (and despite criticism from geologists), models have become entrenched in coastal engineering practice and are now a standard weapon in society's assault on the world's coasts. In this paper, we chart the development of several widely used models, highlight their shortcomings, and speculate on why they remain in use. The disconnect between reality and the mathematics of coastal process models is extreme, and a fundamental reassessment is required.

Using current debates surrounding climate change as an example, this essay offers a postdisciplinary framing of the policy uses of scientific knowledge. Rather than seeing empirical knowledge as driving societal consensus, the causal arrow between science and social values should be understood as flowing in both directions. In the case of climate change, 20 years of climate science has led to few changes in public policy; but we can expect that the dire consequences of climate change, if and when they occur, will cause a rapid shift from impotent squabbling to public and political pressure to geoengineer the climate. I explore the implications of this view, and argue that geologists and society at large should learn how to make effective use of geological ignorance as well as geological knowledge.

Collaboration is a powerful tool in geoscience education and research. The past 50 years have seen dramatic increases in the amount of collaboration and its reach across specialties and disciplines. These trends seem to be driven by (1) the nature of scientific questions; (2) specialization; (3) resource sharing fostered by new equipment and technology; and (4) government and social priorities reflected in funding opportunities. Similar trends are also occurring in geoscience education. Effective collaboration in both research and education requires developing shared goals, values, customs, and management strategies. While collaborations are powerful, leading to results that cannot be obtained by individuals in isolation, they are often time-consuming and slow to achieve initial results, especially when they involve groups with different cultures, values, and expectations. For this reason they require ongoing financial and institutional support. The geoscience community plays a central role in enabling collaborations in geoscience education and research by fostering networking and sharing of information and resources.

The state of geoscience education, in terms of numbers of teachers, students taught, and perceived importance, has been lagging behind the other science disciplines for decades. Part of the reason for this is that geology has commonly been seen as a “derivative” science, by educators, especially when compared to its “experimental” counterparts (for instance, physics and chemistry). However, with current global issues (climate change, scarcity of clean water, increasing fossil fuel usage) facing the populations of the world, being geoscience literate is a must. We show that, in fact, the geological sciences have their own philosophical structure, being both historical and hermeneutic, and it is this specific structure that aids students in addressing these global issues. In addition, we discuss the reasons for using historical controversies as a pedagogical tool for geoscience instruction. The history of geology is rife with scientific controversy, and the use of such a strategy has been shown to be effective for developing students' interest in the content, for sharpening critical-thinking skills, as well as for emphasizing the nature of science. This chapter consolidates the knowledge base by describing the structure of the geosciences in terms of its philosophical, theoretical, and cognitive frameworks. We find that geoscience instruction could well be improved by incorporating history and philosophy of science and employing historical case studies, especially those involving controversy. Two well-known controversies, continental drift/plate tectonics and the Cretaceous-Paleogene extinction event, illustrate these frameworks.

The American polymath and logician Charles S. Peirce (1839–1914) spent much of his professional career working on geodetic measurements. Nevertheless, his very original studies of scientific inference have considerable relevance to geology. Particularly important influences on his views derive from his avid studies of the Scientific Revolution and the Enlightenment, notably the writings of Galileo Galilei (1564–1642) and Immanuel Kant (1724–1804). From Kant, Peirce derived an architectonic and categorical approach to philosophy. Following the example of the Cambridge mineralogist William Whewell (1794–1866), Peirce pursued the history of science in order to uncover the logic of scientific inquiry. His original reading of Galileo revealed that scholar’s reliance upon il lume naturale (“the Light of Nature”) as a guide toward the selection of potentially productive hypotheses from among the many that might be posed in regard to scientific explanation. This principle underpins Peirce’s famous and controversial notion of abduction, or retroduction, i.e., informed guessing, as critical to scientific inquiry. The instinctive tendency of the experienced and informed scientist to “guess right” is essential to the historically demonstrated success of science.

The surface of Mars preserves landforms associated with the largest known water floods. While most of these megafloods occurred more than 1 Ga ago, recent spacecraft images document a phase of outburst flooding and associated volcanism that seems no older than tens of millions of years. The megafloods that formed the Martian outflow channels had maximum discharges comparable to those of Earth’s ocean currents and its thermohaline circulation. On both Earth and Mars, abrupt and episodic operations of these megascale processes have been major factors in global climatic change. On relatively short time scales, by their influence on oceanic circulation, Earth’s Pleistocene megafloods probably (1) induced the Younger Dryas cooling of 12.8 ka ago, and (2) initiated the Bond cycles of ocean-climate oscillation with their associated Heinrich events of “iceberg armadas” into the North Atlantic. The Martian megafloods are hypothesized to have induced the episodic formation of a northern plains “ocean,” which, with contemporaneous volcanism, led to relatively brief periods of enhanced hydrological cycling on the land surface (the “MEGAOUTFLO Hypothesis”). This process of episodic short-duration climate change on Mars, operating at intervals of hundreds of millions of years, has parallels in the Neoproterozoic glaciation of Earth (the “Snowball Earth Hypothesis”). Both phenomena are theorized to involve abrupt and spectacular planet-wide climate oscillations, and associated feedbacks with ocean circulation, land-surface weathering, glaciation, and atmospheric carbon dioxide. The critical factors for megascale environmental change on both Mars and Earth seem to be associated tectonics and volcanism, plus the abundance of water for planetary cycling. Some of the most important events in planetary history, including those of the biosphere, seem to be tied to cataclysmic episodes of massive hydrological change.

ABSTRACT The Columbia River Basin (CRB) is home to the best studied examples of two of the most spectacular geologic processes on Earth and Mars: flood volcanism and catastrophic water floods. Additionally, features formed by a variety of eolian, glacial, tectonic, and mass-wasting processes can also be seen in the CRB. These terrains provide exceptional terrestrial analogs for the study of similar processes on Mars. This field guide describes four one-day trips out of Moses Lake, Washington, to observe a wide variety of Mars analogs.

Abstract The 1920s–1930s debates over the origin of the ‘Channeled Scabland’ landscape of eastern Washington, northwestern USA, focused on the cataclysmic flooding hypothesis of J Harlen Bretz. During the summer of 1922, Bretz began leading field parties of advanced University of Chicago students into the region. In his first paper, published in the Bulletin of the Geological Society of America , Bretz took special care not to mention cataclysmic origins. However, in a subsequent paper in the Journal of Geology , to the editorial board of which he had recently been added, Bretz formally described his hypothesis that an immense late Pleistocene flood, which he named the ‘Spokane Flood’, had derived from the margins of the nearby Cordilleran Ice Sheet. This cataclysm neatly accounted for numerous interrelated aspects of the Channeled Scabland landscape and nearby regions. Nevertheless, the geological community largely resisted Bretz's hypothesis for decades, despite his enthusiastic and eloquent defence thereof. Resolution of the controversy came gradually, initially through the recognition by J. T. Pardee of a plausible source for the flooding: ice-dammed Pleistocene glacial Lake Missoula in northern Idaho and western Montana. Eventually, by the 1960s, the field evidence for cataclysmic flooding became overwhelming, and physical processes were found to be completely consistent with that evidence. The controversy is of philosophical interest in regard to its documentation of the attitudes of geologists toward hypotheses, which illustrate aspects of geological reasoning that are distinctive in degree from those of other sciences.