ABSTRACT The very first scientific paper by Eduard Suess (1831–1914) treats the graptolites of Bohemia in the present-day Czech Republic (in the Upper Proterozoic to Middle Devonian “Barrandian” extending between Prague and Plzeň). This paper is accompanied by superb drawings of his observations in which Suess took great care not to insert himself between Nature as he perceived it in the framework of the knowledge of his day and his readers. His only limitation was the one imposed by the size of his study objects. His technological means did not allow him to see what we today consider the “right” picture. Nevertheless, we can see what he saw and interpret it through a modern lens of understanding. In his drawings, Suess exercised what the great German geologist Hans Cloos later called “the art of leaving out.” This meant that in the drawings, the parts not relevant to the discussion are left only in outline, whereas parts he wished to highlight are brought to the fore by careful shading. Even the parts left only in outline are not schematic, however; instead they are careful reconstructions true to Nature as much as the material and his technological aids allowed. This characteristic of Suess’ illustrations is seen also in his later field sketches concerning stratigraphy and structural geology and in his depiction of the large tectonic features of our globe representing a window into his manner of thinking.

No abstract available.

The Austrian geologist Suess was the person who introduced the concept of eustasy, distinguishing two types of movement, caused by different processes. Negative movements, involving lowering of sea level, were caused by spasmodic subsidence of the ocean floor as a consequence of global contraction. Positive movements, involving rise of sea level, were more continuous and caused by the displacement of seawater by ocean-floor sedimentation. Suess’s eustatic interpretation was disputed by later scholars. Haug, thus, maintained that transgressions on the continents correlated with regressions in the geosynclines, and vice versa, and Haarmann argued for contemporary up and down movement of landmasses, with rises and falls of sea level a secondary consequence. However, the German geologist, Stille, was a confirmed eustasist, arguing that the major movements of the strandline had affected all the continents in much the same sense at the same time. Stille claimed that a series of relatively brief global “orogenic periods” increased the total continental area and caused general regression of the sea. Stille was the first to produce a eustatic curve for the Phanerozoic, but publication of this had to await a paper by Umbgrove shortly before the Second World War. Another Dutchman, Kuenen, was a pioneer in the use of the hypsographic curve to attempt a crude estimate of the amount of sea-level change resulting from a given change in area of land flooded by epicontinental seas. He rejected Suess’s explanations of positive and negative eustasy, preferring with Umbgrove an underlying mechanism bound up with mantle processes. After the Second World War a reaction set in against Stille’s geotectonic ideas, but eustatic studies were given support by oceanographic studies that suggested a plausible mechanism for long-term eustatic changes, and more detailed stratigraphic work across the world, which supported the reality of eustasy. Modern work concentrates on applying the concepts of sequence stratigraphy.

Abstract The appearance of this translation of Eduard Reyer's Geologische Prinzipienfragen (1907) is as timely as John Biram's English translation of Alfred Wegener's Die Entstehung der Kontinente und Ozeane (1912, 4th rev. ed., 1928, Dover, 1966). Both translations mark a general revival of interest in the historical growth of two major geodynamic concepts: gravity tectonics and continental drift. In a way, these two aspects of geodynamics are complementary. Reyer, who lived from 1849 to 1914, drew attention to the potential energy created by vertical crustal movements; Wegener, who lived from 1880 to 1930, stressed the importance of great horizontal displacements. Wegener's book appeared to achieve a real breakthrough for continental drift, an idea that had been ripening since the seventeenth century, but most geoscientists rejected his proposals because of the preconceived opinion that crustal rocks were too strong and that the proposed driving forces too weak for such a process. An entirely new branch of geonomy paleomagnetism had to be developed before enough diagnostic facts were gathered to prove that continental drift did, nevertheless, occur in the Phanerozoic. Similarly, Eduard Reyer developed a clear concept of glide tectonics (Gleitfaltung) through observation and experimentation, but his ideas conflicted with the prevailing contraction theory which was then strongly supported by his teacher and later colleague Eduard Suess (1831-1914). Custom, inertia of thinking, and authority caused a rejection of Reyer's ideas by most of his contemporaries. Disappointed, Reyer devoted his later years to social reform, to the founding of public libraries, and to various philosophical problems. Only once, because he was deeply convinced of the correctness of his ideas, did he turn his efforts and his genius to the fundamental problems of geology. Geologische Prinzipienfragen, his last book on geology, has now been translated into English: it represents a matured concept of geology at the beginning of the twentieth century. Reyer's book is of great value for two major reasons: first, it contains many examples of unbiased observation, clear inductive thinking, and verification by means of experimental tests. Secondly, by stressing the role of gravity as a driving force, it marks a milestone in the development of structural geology.

Abstract The Caledonian Orogeny lasted from the late Cambrian to the Devonian with the main collisional events occurring during Ordovician and Silurian times. Direct evidence of the extent of this orogenic event across central Europe is limited because of the lack of outcrops of this age. The Caledonian Orogeny, together with the subsequent Variscan and Alpine orogenies, is one of a succession of major tectonic events which have defined the geological evolution of Central Europe. Thus, the present configuration and condition of the lithosphere of central Europe is the result of superimposed periods of deformation (Fig. 7.1 ). Consequently, a wide range of investigative techniques needs to be employed to unravel these events in order to determine the properties of the various elements of the Caledonides and to elucidate the evolution of the Caledonian Orogeny. Additionally, evidence of the orogeny is deeply buried beneath thick successions of younger sediments, e.g. Dutch and North German Basin, or has been reworked extensively by later events, e.g. Belgium or to the SE of the Trans-European Suture Zone. The word ‘Caledonia’, the Latin name for northern Scotland, was used by Eduard Suess (1885-1909) not only to describe a geographic region but also to indicate an orogen he termed ‘Caledonisches Gebirge’. Furthermore, Suess was the first to put his definition into a tectonic context: ‘Die in der Kaledonischen Faltungsära gebildeten Gebirge treten vor allem in Irland, Wales, Schottland und im Westteil Skandinaviens in Erscheinung’. [The mountains built during the Caledonian folding era appear particularly in Ireland,

Abstract The Austrian geomorphologist Eduard Suess was the first to recognize the importance of the African rift valleys. However, Suess never visited Africa, and he would never have been able to make his perceptive recognition of this aspect of the geomorphology of the African continent had it not been for earlier field explorers. The discovery of the African rift valleys can be traced back to the middle part of the nineteenth century. At the time, little was known about the interior of much of Africa, partly because, due to uplift of the continental rim, easy access to much of the interior of Central Africa was precluded by major cataract systems near the mouths of many of the larger rivers (Congo, Niger, Zambesi). The mainspring for the exploration of East Africa came from a largely unacknowledged source, the missionary community on the East African coast. In 1846, the Church Missionary Society of London established a mission station at Kisuludini in the Rabai Hills on the mainland across from Mombasa Island. The mission was started by Johann Krapf, who was soon joined by Johann Erhardt and Johann Rebmann. All three were Lutherans, trained at Basel; apparently the Society had difficulties recruiting British missionaries for the arduous mission life in East Africa ( Oliver 1952 ). In addition to their pastoral duties, the missionaries travelled inland in attempts to find suitable sites for further mission stations and, during these journeys, they made observations on the geographical features they encountered. It was on such journeys that Rebmann

The whole southern border of Eurasia advances in a series of great folds towards Indo-Africa; these folds lie side by side in closely syntactic arcs, and for long distances they are overthrust to the south against the Indo-African table-land… This circumstance distinctly indicates that the folding of the uppermost part of the Earth’s mass is, under certain conditions, only the expression of a forced adaptation… A great part of this folding is of recent age, or has been continued into very recent times; it is not certain that the movement has ended. —Eduard Suess (1904), The Face of the Earth , vol. 1, p. 596–597

Abstract Geology as a discipline emerged in Austria between the eighteenth and nineteenth centuries from mineralogy and geognosy, two sciences dominated by descriptive rather than theoretical approaches. Austria, in this context, refers to the conglomerate of different states under the Habsburg Monarchy that existed until 1918. Two key aspects shaped the development of geology and the establishment of public institutions: mining industries and natural history collections. As a result of their close relation, the k.k. Geologische Reichsanstalt (Imperial Geological Survey) was founded in Vienna in 1849, which had repercussions for the entire empire. The Reichsanstalt carried out a geological survey of all the territories of the Habsburg Monarchy, resulting in a unifying geological map published in 1867. Geology was triggered and accelerated not least by the industrialization processes of the nineteenth century. From the 1850s, geology no longer focused only on the empire and its provinces, but took a global perspective. From 1862 a growing number of university chairs for geology were established, making the ‘new’ academic discipline visible. The internationally outstanding research work of Eduard Suess contributed to this success story.

T. C. Chamberlin’s 1898 diastrophic (tectonic) control paper was a short editorial-like response to a questionnaire about geologic time divisions; the more famous and even shorter 1909 paper restated the primacy of diastrophic control of worldwide unconformities as a basis for correlation. This hypothesis derived from Chamberlin’s beloved planetesimal theory, which postulated a gravitationally shrinking globe. The earth was considered entirely solid with isostatic equilibration being effected by periodic vertical adjustments between deep, wedge-shaped blocks. During early planetesimal accretion, minor heterogeneities augmented by weathering processes led to denser, lower oceanic and lighter, higher continental wedges. Shrinkage-induced global stress caused spasmodic sinking of the oceanic wedges, which produced elevation (or lesser subsidence) of continental ones, thus regression. During subsequent, longer diastrophic quiescence, erosion reduced continents and extended the “circumcontinental submarine terrace” (shelf) by sedimentation. Areas elevated above their isostatic equilibrium level would slowly settle back to equilibrium. This crustal sinking, coupled with sedimentation-induced displacement of sea water, now caused transgression. The oscillations of sea level would also dramatically affect organic evolution and produce important climatic effects as well. During continental emergence, weathering would consume CO 2 , causing cooling, but during transgressions, CO 2 would accumulate in the atmosphere to cause greenhouse warming. Such climatic changes should accentuate the effects of global diastrophism as the “ulterior basis of time divisions.” Although Chamberlin did not employ the term eustasy, he presented an appealing and influential mechanism, which showed striking resemblances to Eduard Suess’ concepts of global contraction and periodic eustatic changes published ten years earlier. Chamberlin’s hypothesis of repetitive, synchronous worldwide changes of sea level with resulting universal unconformities punctuating the global stratigraphic record— “correlated pulsations”—was to have a profound effect upon many subsequent workers, especially in North America, and was an important precursor of modern sequence stratigraphy.