The Development of the Rhine Author(S): E
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The Development of the Rhine Author(s): E. M. Yates Source: Transactions and Papers (Institute of British Geographers), No. 32 (Jun., 1963), pp. 65- 81 Published by: Blackwell Publishing on behalf of The Royal Geographical Society (with the Institute of British Geographers) Stable URL: http://www.jstor.org/stable/621060 . Accessed: 04/08/2011 06:12 Your use of the JSTOR archive indicates your acceptance of JSTOR's Terms and Conditions of Use, available at . http://www.jstor.org/page/info/about/policies/terms.jsp. JSTOR's Terms and Conditions of Use provides, in part, that unless you have obtained prior permission, you may not download an entire issue of a journal or multiple copies of articles, and you may use content in the JSTOR archive only for your personal, non-commercial use. Please contact the publisher regarding any further use of this work. Publisher contact information may be obtained at . http://www.jstor.org/action/showPublisher?publisherCode=black. Each copy of any part of a JSTOR transmission must contain the same copyright notice that appears on the screen or printed page of such transmission. JSTOR is a not-for-profit service that helps scholars, researchers, and students discover, use, and build upon a wide range of content in a trusted digital archive. We use information technology and tools to increase productivity and facilitate new forms of scholarship. For more information about JSTOR, please contact [email protected]. Blackwell Publishing and The Royal Geographical Society (with the Institute of British Geographers) are collaborating with JSTOR to digitize, preserve and extend access to Transactions and Papers (Institute of British Geographers). http://www.jstor.org THE DEVELOPMENT OF THE RHINE E. M. YATES, M.SC., PH.D. (Lecturerin Geography,University of LondonKing's College) Trieb nieder und nieder, Du herrlicher Rhein! Du kommst mir ja wieder, Lasst nie mich allein. C. BRENTANO DERRHEIN stimulates the imagination: the Vandal horde crossing the river on the last day of 406; Charlemagne'scampaigns; the long strugglebetween France and Germany. The river has indeed played an importantrole in both the political and the economic history of western Europe, because it joins and provides a route between three major relief units: the Alps; the Hercynian uplands; and the north European plain (Fig. 1). Yet this link has only recently been achieved (in the geological sense). The Rhine is not an example of a superimposedriver, but it is a remarkablefusion of originally distinct drainage elements. The fusion has taken place during the course of Tertiary and Quaternarytime. The Rhine Valley in OligoceneTimes The period was marked by a widespread marine transgression, generally reaching its maximum in mid-Oligocene (Stampian) times. The sea reached the northern edge of the Rhenish Uplands, entered the Cologne Bay and penetrated the Hessian Corridorto the Rhine Rift Valley.l The latter had been drowned in the lower Oligocene from the Swiss Foreland as far as the present Neckar confluence. In the mid-Oligocene, however, the southern sea reached forwardto the Mainz Basin, joined the sea occupying the Hessian Corridor,and thus com- pleted a link between the North Sea and Tethys across the present Rhine course. Another strait, close to the route now followed by the Rhine-Marne canal, may have linked the Rift Valley with the Paris Basin.2From the SwissForeland a further arm of the sea, probably quite narrow, extended along the northern Alps into Bavaria. In both the Swiss Foreland and the Rhine Rift Valley very considerable deposition took place. The Oligocene beds of the Rift Valley reach a thickness of 1500 metres, and contain important reserves of salt and potash, and some oil. The 'Untere Meeresmolasse'(Stampian) of the Foreland is up to 1000 metres thick. In upper Oligocene times (Chattian) the marine deposits of the Foreland were succeeded by fresh water deposits, the 'Untere Siisswassermolasse'.The forerunners of the present Alpine headstreams of the Rhine, stimulated by the tectogenesis, contributed to this sedimentation by building great rock deltas, which now form the conglomerate 'Nagelfluh' and give rise to mountains in the Foreland such as Rigi and Speer (Fig. 1). This sedimentation blocked temporarily in upper Oligocene times (Chattian) the southern exit from the Rift 65 66 THE DEVELOPMENT OF THE RHINE Ki!ometres 0 100 200 ! I * . I, , 1 I . I . i N 0 FIGURE1-The Rhine: key to places named in text. THE DEVELOPMENT OF THE RHINE 67 Valley. Subsequentdeposition in the Rift Valley took place under fresh water or brackish conditions, leaving marls distinguished by the presence of the mussel Cyrena convexa, the 'Cyrenenmergel',and fresh water limestone distinguished by the presence of the snail Helix ramondi.In the Bavarian Strait east of the Lech some marine deposition took place in the upper Oligocene, as is demonstrated by the PrombergerBeds, but these are underlainand overlain by Cyrenenmergeland show a fluctuatingmargin to the sea that extended from the Hungarian Basin. Marine molasse is now exposed in Bavaria along a narrow- faulted zone that marks in a tectonic sense the northern boundary of the Alps.3 In these narrow seas the Rhenish Uplands formed a broad peninsula (Fig. 2a). These Uplands are of course a remnant of the Hercynianmountains, composed of a great series of Devonian sediments, lying in a number of com- plicated folds. By the beginning of the Tertiary epoch the mountains had been largely reducedto a plain with rounded residual hills, the latter formed along the quartzite outcrops and giving a relief of some 200 metres. A long period of tropical or sub-tropical weathering had led to a deep decomposition of the shales, and, where this material was washed into hollows, the formation of early Tertiary clays, which are of some importance in the ceramic industry. On the plains flourished luxuriant forests, from which are derived the lignite reserves of the Rhinelands. The drainage differed considerably from that of today. The Oligocene streams have left the gravels known as the Vallendar Schotter, and from these gravels the pattern of drainage can be reconstructed (Fig. 2a). The river aligned along the present courses of the Mosel and Lahn flowed, in the reverse direction to the modern Lahn, into the Hessian Corridor.4 A distributaryof this river followed the same direction as the present Rhine into the Cologne Bay. The Vallendar Schotter rise to an altitude of 480 metres, but they are well developed upon an important 400-metre surface within the uplands, into which the Rhine, Mosel and Lahn are incised. This surface, occasionally reaching a width of 30 kilometres, is the 'Trog' of A. Philippson.5 Stratigraphicallyabove the Vallendar Schotter, and apparently laid down under brackish conditions, are sediments derived from the products of the Tertiary weathering, the Aren- berger Beds. The late Oligocene and early Miocene appears indeed to have been a period of great sedimentationin which the old Vallendardrainage divides were buried and the streams gradually replaced by strings of salty pools. The forma- tion of the Trog has been attributed by H. Louis to the lateral planation of the debris-laden streams responsible for the sedimentation.6This is, however, far from being the only explanation for the formation of the Trog. Above the Trog are two further surfaces at 500 and 600 metres, the Rumpfflachen,designated respectively Rl and R2. Above these high surfaces there are residual hills, in which traces of a third surface have been distinguishedat 740 to 800 metres, the R3. The higher surfaces R1, R2, R3 and the Trog have been regarded alterna- tively as derived from one original surface, buckled during uplift from Miocene times.7 This is supported by the presence on the Trog, in situ, of older Tertiary G Oo00 0T1 Ct- z C ~T1 cd 2 FIGURE 2a (left)-The Rhine valley in Oligocene times (Stampian); 2b (middle)-The Rhine valley in Miocene times (Helvetian); 2c (right)- The Rhine valley in Pliocene times (Astian). THE DEVELOPMENT OF THE RHINE 69 weathered complexes. Evidence for buckling of the surfaces above the Trog comes from the courses of tributariesof the Mosel, such as the Kyll, which are, or appear to be, antecedent to buckling. They cross remnants of the R2 surface in their middle courses, flowing from R1 across R2 to the Trog. These inter- pretations suggest either an Oligocene or a Miocene age for the Trog and this latter date receives confirmationfrom the Westerwaldwhere the surface is cut in basalt of lower Miocene age. Because of the presence upon it of flints the R3 surface has also been considered as Eocene or even Senonian. In general it may be said that the conflict of views on the age of the upper surfacesof the Rhenish Uplands is similar to that associated with the Welsh Uplands. A similar conflict of opinion applies to the Belgian part of the massif, the Ardennes. Both eustatic change and crustal warping have been argued as explanations for the various surfaces, including that at 400 metres. Some of the various interpretationsare given by A. Godard, and in table form by J. F. Gellert.8 The coastline of the peninsula on which these developments took place fluctuated considerably during the Oligocene. In the upper Oligocene the sea withdrew from the northern shores and the swamp forests extended into the Cologne Bay. The subsidence of the latter led to the accumulationthere of up to 200 metres of lignite, the brown coalfield of Cologne. On the southern shores a transgression of short duration linked the northern end of the Rhine valley with the Neuwied Basin, as shown by the presencewithin the Basin of the Cyrenen- mergel. This linkage, through the Bingen Gate, foreshadowed a later develop- ment of the Rhine and presumably led to changes in the already disrupted Vallendar drainage pattern.