Paleogeography And Sedimentary Development Of Two Deep Marine Foreland Basins

This dissertation comprises three chapters focusing on the evolution of marine sedimentary successions that formed as the fill of large submarine channel belts and their tributary systems. These channel belts serve as conduits for gravel- and sand-laden sediment gravity flows along the axes of narrow, elongate foreland basins. In the past, axial channel belts have not been widely recognized in submarine foreland basins (Mutti et al., 2003). However, recent studies have demonstrated the presence of axial channels, 3-8 km in width and > 100 km in length, in a number of marine foredeeps including the Cretaceous Magallanes Basin, southern Chile, and the Tertiary Molasse Basin, northern Austria (De Ruig and Hubbard, 2006; Hubbard et al., 2008, 2009). Additional studies have shown that similar channels are common in submarine trough-shaped basins in other convergent margin settings such as the Peru-Chile trench (Thornburg et al. 1990, Völker et al., 2006), the Hikurangi trough, offshore New Zealand (Lewis and Pantin, 2002), and the Nankai trough, offshore Japan (Fig. 1 in Moore et al., 2007), as well as in modern oceanic rift basins, such as the Maury channel in the Northeast Atlantic Rockall Basin (Cherkis et al., 1973) and the Northwest Atlantic Mid-Ocean Channel (NAMOC) in the Labrador Sea (Hesse et al., 1987, 1990; Hesse, 1989, Klaucke et al., 1998). These occurrences suggest that axial channels may be common sediment transport fairways in elongate deep-water basins in a variety of tectonic settings. This thesis investigates the sedimentary evolution, stratigraphic architecture, and paleogeography of such channel systems in two distinct, yet analogous and complementary research areas: the Magallanes foreland basin in southern Chile, and the Molasse foreland basin in northern Austria. The main objectives of this study are: a)to characterize the processes of submarine sediment transport and deposition in the study areas, b)to explain the associated filling patterns of ancient submarine axial channels and their tributaries, and c)to reconstruct the paleogeography of an ancient seafloor in order to better understand deep-marine sediment dispersal patterns in narrow elongate basins. The Magallanes Basin is a retro-arc foreland basin characterized by a deep-marine filling history from the Cenomanian/ Turonian (Fildani et al., 2003; Fosdick et al., in press) to the Campanian (Chapter 3). The numerous coarse-grained submarine channel and lobe complexes of the Turonian to Campanian Cerro Toro Formation represent a large north-south oriented channel belt that funneled sediment gravity flows along the axis of the foreland basin parallel to the active thrust front (Hubbard et al., 2008). This main axial trunk channel belt was probably fed by at least one, and possibly numerous, tributary channel systems coming off the Andean mountain front to the west. Similarly, sedimentation within the Upper Austrian Molasse Basin during the late Oligocene to early Miocene was largely controlled by an axial trunk channel that was fed by a deltaic system to the west and a tributary system lying along the Inntal fault zone to the southwest (De Ruig and Hubbard, 2006). Three studies were undertaken in order to illuminate the processes and architecture of the fill of submarine foreland basin axial channels: the interaction of submarine debris flows and turbidity currents within the axial channel in the Molasse Basin (Chapter 1), the stratigraphic and architectural evolution of coarse-grained deep-water deposits in a tributary system setting in the Magallanes Basin (Chapter 2), and the paleogeography of the Magallanes Basin axial channel belt and its tributary system and the associated basin-filling pattern over time (Chapter 3). Multiple techniques were combined to achieve these goals, including field mapping, sedimentological analysis of outcrops and rock cores, interpretation of wireline logs and 3D seismic-reflection data, U/Pb dating of zircons, strontium isotope stratigraphy, and a novel approach to lithofacies proportion modeling (Stright et al., 2009).

This dissertation comprises three chapters focusing on the evolution of marine sedimentary successions that formed as the fill of large submarine channel belts and their tributary systems. These channel belts serve as conduits for gravel- and sand-laden sediment gravity flows along the axes of narrow, elongate foreland basins. In the past, axial channel belts have not been widely recognized in submarine foreland basins (Mutti et al., 2003). However, recent studies have demonstrated the presence of axial channels, 3-8 km in width and> 100 km in length, in a number of marine foredeeps including the Cretaceous Magallanes Basin, southern Chile, and the Tertiary Molasse Basin, northern Austria (De Ruig and Hubbard, 2006; Hubbard et al., 2008, 2009). Additional studies have shown that similar channels are common in submarine trough-shaped basins in other convergent margin settings such as the Peru-Chile trench (Thornburg et al. 1990, Völker et al., 2006), the Hikurangi trough, offshore New Zealand (Lewis and Pantin, 2002), and the Nankai trough, offshore Japan (Fig. 1 in Moore et al., 2007), as well as in modern oceanic rift basins, such as the Maury channel in the Northeast Atlantic Rockall Basin (Cherkis et al., 1973) and the Northwest Atlantic Mid-Ocean Channel (NAMOC) in the Labrador Sea (Hesse et al., 1987, 1990; Hesse, 1989, Klaucke et al., 1998). These occurrences suggest that axial channels may be common sediment transport fairways in elongate deep-water basins in a variety of tectonic settings. This thesis investigates the sedimentary evolution, stratigraphic architecture, and paleogeography of such channel systems in two distinct, yet analogous and complementary research areas: the Magallanes foreland basin in southern Chile, and the Molasse foreland basin in northern Austria. The main objectives of this study are: a)to characterize the processes of submarine sediment transport and deposition in the study areas, b)to explain the associated filling patterns of ancient submarine axial channels and their tributaries, and c)to reconstruct the paleogeography of an ancient seafloor in order to better understand deep-marine sediment dispersal patterns in narrow elongate basins. The Magallanes Basin is a retro-arc foreland basin characterized by a deep-marine filling history from the Cenomanian/ Turonian (Fildani et al., 2003; Fosdick et al., in press) to the Campanian (Chapter 3). The numerous coarse-grained submarine channel and lobe complexes of the Turonian to Campanian Cerro Toro Formation represent a large north-south oriented channel belt that funneled sediment gravity flows along the axis of the foreland basin parallel to the active thrust front (Hubbard et al., 2008). This main axial trunk channel belt was probably fed by at least one, and possibly numerous, tributary channel systems coming off the Andean mountain front to the west. Similarly, sedimentation within the Upper Austrian Molasse Basin during the late Oligocene to early Miocene was largely controlled by an axial trunk channel that was fed by a deltaic system to the west and a tributary system lying along the Inntal fault zone to the southwest (De Ruig and Hubbard, 2006). Three studies were undertaken in order to illuminate the processes and architecture of the fill of submarine foreland basin axial channels: the interaction of submarine debris flows and turbidity currents within the axial channel in the Molasse Basin (Chapter 1), the stratigraphic and architectural evolution of coarse-grained deep-water deposits in a tributary system setting in the Magallanes Basin (Chapter 2), and the paleogeography of the Magallanes Basin axial channel belt and its tributary system and the associated basin-filling pattern over time (Chapter 3). Multiple techniques were combined to achieve these goals, including field mapping, sedimentological analysis of outcrops and rock cores, interpretation of wireline logs and 3D seismic-reflection data, U/Pb dating of zircons, strontium isotope stratigraphy, and a novel approach to lithofacies proportion modeling (Stright et al., 2009).

The outcome of a symposium held in Fribourg, Switzerland, this book fulfils two aims. Firstly, it represents a collection of case-studies covering a wide range of basin types and tectonic and stratigraphic settings. Secondly, it highlights a number of specific themes such as the history of subsidence and its relation to orogenesis, the stratigraphic architecture of the basin fill and the petrographic signature of foreland basin deposits. The text comprises five sections with a total of 26 contributions and it will be of special interest to teachers, researchers and petroleum geologists concerned with the relationships between tectonics and sedimentation. This is because it clearly demonstrates the many recent advances within the field of basin analysis by an integration of sedimentological, stratigraphical, structural and geophysical data.

This book incorporates developments in chronostratigraphy, sequence stratigraphy and sedimentation and tectonics that have taken place during the last decade. In particular, the wealth of case studies that have appeared since the late 1980s, focusing on sequence architecture and the relationships between sedimentation and tectonics, have required a virtually complete rewriting of Chapters 6 to 9. The global-eustasy model that was popular as a mechanism for sequence generation at the time of writing of the earlier editions of this book has been downplayed in this edition in the face of abundant new evidence pointing to the importance of tectonism as a process that may generate sequences over a wide range of temporal and physical scales. Amongst other additions, this edition contains new sections describing such topics as basin inversion and basement control of sedimentary basin development, and a range of new case studies of the plate tectonics of sedimentary basins.

A strong case can be made that foreland basins are where the casual links between sedimentation and tectonic events were first recognized, as evidenced by the interpretations of geologists working in classic foreland areas. This Special Publication was derived from a Research Symposium entitled "Stratigraphic Sequences in Foreland Basins" held at the AAPG-SEPM joint annual meeting on June, 1992, in Calgary, Alberta, Canada. This volume provides a well-balanced perspective of current research on foreland basin stratigraphy and also serves as another element in the evolving framework that comprises our understanding of foreland basins. Given that so many of earth's resources are found in foreland basins and that foreland basin strata often provide the only preserved record of the tectonic events that led to basin development, the impetus for continued studies of foreland basin strata should remain for many generations of geologists to come.

Taking a new global approach, this unique book provides an updated review of the geology of Iberia and its continental margins from a geodynamic perspective. Owing to its location close to successive plate margins, Iberia has played a pivotal role in the geodynamic evolution of the Gondwanan, Rheic, Pangea, Tethys s.l. and Eurasian plates over the last 600 Ma of Earth's history. The geological record starts with the amalgamation of Gondwana in the Neoproterozoic succeeded by the rifting and spreading of the Rheic ocean; its demise, which led to the amalgamation of Pangea in the late Paleozoic; the rifting and spreading of several arms of the Neotethys ocean in the Mesozoic Era and their ongoing closure, which was responsible for the Alpine orogeny. The significant advances in the last 20 years have attracted international research interest in the geology of the Iberian Peninsula. This volume presents the most comprehensive, and updated description of the Alpine cycle in Iberia. This volume focuses in the different geological events during the Alpine orogeny as well as the lithological succession . This book is of interest not only for scientists of Portugal and Spain but also for geoscientists searching for analogies for oil and gas as well as tourists visiting the main mountain ridges of Iberia such as the Pyrenees.

In the past, interest in sedimentary structures has arisen mainly from the expectation that these features might be a guide to the environment of depo sition. But many sedimentary structures have also proved useful in determining stratigraphic order in nonfossiliferous, steeply inclined beds especially in Pre cambrian terranes. As the sequence problem has been reviewed at length by Shrock, it seemed to us, therefore, that the time is now ripe for a new look at sedimentary structures, not with respect to "top and bottom," but with reference to "fore and aft. " Much of the present-day interest in these structures stems from their usefulness in mapping of paleocurrents. A stage has been reached where there is need for a work which assembles, digests, and organizes our collective knowledge of the usefulness of directional properties of sediments and their application to basin analysis. This we have attempted to write. The desirability and need for such a book occurred to both of us independently. Upon discovering our mutual interest, we decided that a better book could be written by collaboration. Fortunately this collaboration became a reality because of support by the Guggenheim Foundation of one of us and the cooperation and support of The Johns Hopkins University of both of us. We acknowledge with thanks this indispensable aid.

In recent years there have been rapid strides in our understanding of plate-tectonic processes, many developments in methods of basin analysis, and the accumulation of much new surface and subsurface geological and geophysical data. Projects such as COCORP (in the United States) and Lithoprobe (in Canada) have provided essential insights into the deep crustal structure of the continent. Synthesis of all the available information about North America’s geological regions has not been attempted systematically since the “Decade of North American Geology project undertaken by the Geological Society of America and the Geological Survey of Canada nearly twenty years ago. The book commences with a summary of the Phanerozoic geological history of the United States and Canada, illustrated with a suite of new paleogeographic maps, and tying in each of the subsequent regional chapters by the inclusion of numerous cross-references. This followed by a set of fifteen regional syntheses of the principal tectonic regions of the United States and Canada, focusing on the stratigraphic and tectonic history of the major sedimentary basins. Most of these chapters have been contributed by specialists, drawing on their own research, and providing interpretive summaries of a type not previously attempted. * Up-to-date synthesis of the sedimentary/tectonic history of the major areas of the United States and Canada * Up-to-date references * Many new color maps