ZusammenfassungDas Dissertationsgebiet yon Hans Cloos im 6stlichen Jura liegt im Grenzbezirk zwischen den unterterti~iren Strukturen des Tafeljuras, einem Teii des Stidostens des Rheingrabens, und den neogenen Falten und •berschiebungen des Faltenjuras. In jtingster Zeit wurden reflexionsseismische Aufnahmen yon ausgezeichneter Qualit~it im 6stlich anschlief~enden Gebiet durchgeftihrt. Sie f6rderten kritische neue Informationen zutage tiber die Untergrundstruktur und die Beziehungen zwischen drei aufeinanderfolgenden tektonischen Ereignissen. Das ~ilteste ist dokumentiert in einem mehrere Kilometer tiefen und komplex zerbrochenen und gefalteten spiitpai~iozoischen Trog, der ungef~ihr ONO streicht. Seine wichtigsten Randbruchzonen wurden im Unterterti~ir reaktiviert, und zwar entstanden leicht zerbrochene Flexuren und kleine Falten, die in der Tiefe wurzeln und eine Amplitude von ungef~ihr 100-300 Meter erreichen. AbstractThe thesis area of Hans Cloos in the eastern Jura straddles the boundary between the Paleogene structures of the Tabular Jura, a part of the southeastern end of the Rhine graben, and the Neogene folds and thrusts of the Folded Jura. A recent reflection seismic survey in the area adjacent to the east provides new information on the subsurface structure and the relation between three superposed tectonic events. The main boundary fault zones of a deep and complexly faulted late Paleozoic trough, trending ENE, were reactivated in the early Tertiary. Faulted flexures and small folds, rooted in the basement and Paleozoic, with an amplitude of usually 100 to 300 m were produced, rather than the normal faults typical for the extensional fields of the Rhine-Bresse graben system in the west and the Bavarian Molasse basin in the east. This suggests their being part of a transform zone between these extensional fields. During Jura d6collement in the Neogene these inherited, deeply rooted sub-d~collement structures remained passive: their small size is kinematically incompatible with the intense subsequent thrusting and folding of the thin Mesozoic-Tertiary skin. However, thrust ramps were apparently nucleated at the respective southern foot of these Paleogene flexures and folds. The best defined and simplest of these composite structures is the Mandach structure within the Tabular Jura, a south-facing flexure of about 300 m relief, developed in the Paleogene by reactivation of the northern border fault zone of the Paleozoic trough. In the Neogene a 536 H.P. LAUBSCHER north-vergent d6collement thrust, which is connected with the regional Jura d&ollement in the middle Triassic evaporites, was initiated at its site.The southernmost nucleation point at the southern limit of the folded Jura was apparently re-used after intervals of northward spreading of d~collement. There is evidence that a similar succession of events took place in the central and western Jura as well. Regionally, the boundary faults of at least some of the Paleozoic troughs were reactivated in the early Tertiary as transform zones linking the...

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