Paleomagnetic Rotations and Continental Deformation

One of the most interesting results obtained in the last two decades in the study of crustal deformation has been the recognition that large regions of continental crust undergo rotations about vertical axis during deformation. Proof of such rotations has come through the paleomagnetic studies, which reveal rotations when paleomagnetic declinations within the deforming region arc compared with those found in coeval rocks in the stable regions outside the deforming zone. Such rotations were first described in Oregon then in the North American Cordilleras and in Southern California and were a surprise to everyone. Even in California which, as a result of oil exploration, was among the best geologically explored regions in the world, no one could claim to have predicted that these rotations would be found. Rotations have subsequently been found in other areas of recent continental tectonic activity, notably in the Basin and Range province, New Zealand, the Andes, Greece and Western Turkey, so that they appear as an important feature of continental deformation.

Proceedings of the NATO Advanced Research Workshop, Loutra Edipsou, Greece, May 8-13, 1988

Résumé
Proceedings of the NATO Advanced Research Workshop, Loutra Edipsou, Greece, May 8-13, 1988

Contenu
Block Rotations in Continental Crust: Examples from Western North America.- 1. Introduction.- 2. Definitions.- 3. Types of rotation and their characteristics.- 4. Discussion.- The Kinematics and Dynamics of Distributed Deformation.- 1. Introduction.- 2. Fluid Dynamics.- 3. Rotations about Vertical Axes in Deforming Zones.- 4. Pinned or Floating Blocks?.- 5. Kinematic Stability.- 6. Conclusion.- Relations between Seismicity and Paleomagnetic Rotations in Zones of Distributed Continental Deformation.- 1. Introduction.- 2. A simple description of continuous deformation.- 3. Seismicity and distributed deformation.- 4. An example of distributed deformation achieved by faulting.- The Detection of Rotations by Surveying Techniques.- 1. Introduction.- 2. Terrestrial method.- 3. Satellite techniques.- 4. The surveying estimation process.- 5. Assessement of quality.- 6. Optimal design methods.- 7. Conclusions.- Geodetic Measurements Of Continental Deformations: Projects and First Results.- 1.Introduction.- 2. Methods.- 3. Data.- 4. Comparison with a Plate Tectonic Model.- 5. Interpolation Techniques.- 6. Conclusions.- Continental Rotational Deformation: Examples from Greece.- 1. Introduction.- 2. Neotectonic rotational deformation in Chalkidiki Peninsula (Northern Greece)..- 3. Paleomagnetic and structural evidence for recent deformation in the South Aegean Active Arc (Melos Island)..- 4. Conclusion.- Cenozoic Magmatism, Deep Tectonics, and Crustal Deformation in the Aegean Sea.- 1. Introduction.- 2. The data.- 3. Space-time distribution of the magmatism.- 4. Petrochemistry.- 5. Implications for the deep tectonics.- 6. Discussion.- A Pattern of Block Rotations in Central Aegea.- 1. Introduction.- 2. Geological setting..- 3. Paleomagnetic method.- 4. Results and discussion..- 5. Conclusion.- Late Cenozoic Rotatons along the North Aegean Trough Fault Zone (Greece); Structural Constraints.- 1. Introduction.- 2. Kinematics of the Late Cenozoic faults in the Aegean basins located on both sides of the North Aegean trough fault zone.- 3. Directions of the Early Cenozoic folds on both sides of the western termination of the North Aegean trough.- 4. Conclusions.- Some Experiments on Block Rotation in the Brittle Upper Crust.- 1. Introduction.- 2. Domino domains in Coulomb materials..- 3. Pull-apart domino.- 4. Continental indentation..- 5. Conclusions.- Large Rates of Rotation in Continental Lithosphere. Undergoing Distributed Deformation.- 1. Introduction.- 2. Deformation of the continental lithosphere.- 3. Discussion.- Strain and Displacement in the Brittle Field.- 1. Introduction.- 2. The local characteristics of strain in the brittle field..- 3. The spatial integration of local strain data: the use of strain trajectories..- 4. Conclusion..- Regional Deformation by Block Translation and Rotation.- 1. Introduction.- 2. Deformation by block displacement and rotation: kinematics..- 3. Pre- and post-faulting deformation.- 4. Faults as surfaces of weakness.- 5. Relation between shallow and deep crustal deformation.- 6. Concluding remarks.- Mechanics of Distributed Fault and Block Rotation.- 1. Blocks and fault rotations.- 2. Field evidence.- 3. Material rotation vs. stress field rotation.- 4. Relevance to geodynamies.- 5. Relevance to earthquake prediction..- 6. Conclusion.- Crustal Rotation and Fault Slip in the Continental Transform Zone in Southern California.- 1. Introduction.- 2. Facts concerning deformation.- 3. Amounts of dextral shear.- 4. History of fault movements.- 5. What has been learned?.- 6. Questions and problems remaining.- Evidence for Contemporary Block Rotation in Strike-Slip Environments: Examples from the San Andreas Fault System, Southern California.- 1. Introduction.- 2. Data and interpretations.- 3. Discussion.- The Importance of Magnetostratigraphy for Studies of Tectonic Rotations: Examples from the Mio-Pliocene of California.- 1. Introduction.- 2. Ridge Basin.- 3. Purisima Formation.- 4. Conclusion.- The Application of Palaeomagnetism to Extensional Tectonics: A Palaeomagnetic Study of the Parker District, Basin and Range Province, Arizona..- 1. Introduction.- 2. Geology and sampling.- 3. Paleomagnetic results.- 4. Discussion.- Mechanisms of Cenozoic Tectonic Rotation, Pacific Northwest Convergent Margin, U.S.A..- 1. Introduction.- 2. Long-term dextral shear along the margin.- 3. Basin-Range extension.- 4. Discussion.- Rotation of Central and Southern Alaska in the Early Tertiary: Oroclinal Bending By Megakinking?.- 1. Introduction.- 2. Paleomagnetic Evidence.- 3. Discussion.- 4. Conclusions.- Paleogeography and Rotations of Arctic Alaska - An Unresolved Problem.- 1. Introduction.- 2. Background.- 3. Paleomagnetism.- 4. Paleomagnetic data for Alaska.- 5. Discussion.- Palaeomagnetic Estimates of Rotations in Compressional Regimes and Potential Discrimination Between Thin-Skinned and Deep Crustal Deformation..- 1. Introduction.- 2. Rotations in thin-skinned thrusting; an example from SW Dyfed, Wales..- 3. Rotations in Basement thrust sheets; an example from the Axial zone, Spanish Pyrenees.- 4. Conclusions.- Palaeomagnetic Evidence for Block Rotations and Distributed Deformation of the Iberian-African Plate Boundary.- 1. Introduction.- 2. Palaeomagnetic Results.- 3. Discussion.- Fault Block Rotations in Ophiolites: Results of Palaeomagnetic Studies in the Troodos Complex, Cyprus..- 1. Introduction.- 2. Crustal Structure of the Troodos ophiolite.- 3. Palaeomagnetic units.- 4. Method of analysis.- 5. Extensional deformation.- 6. Strike-slip deformation.- 7. Conclusions.- Paleomagnetism in SE Asia: Sinistral Shear Between Philippine Sea Plate and Asia..- 1. Introduction..- 2. Philippine Sea Plate..- 3. Luzon, northern Philippines..- 4. Tectonics of Philippines and Philippine Sea Plate..- Palaeomagnetic Constraints on the Early History of the Møre- Trøndelag Fault Zone, Central Norway.- 1. Introduction.- 2. Regional geology sampling and magnetic fabrics.- 3. Paleomagnetic and rock-magnetic experiments.- 4. Paleomagnetic reference data.- 5. Interpretation of remanence data.- 6. Discussion.- Paleomagnetically Observed Rotations along the Hikurangi Margin of New Zealand.- 1. Introduction.- 2. Plate reconstructions.- 3. The Hikurangi margin.- 4. Paleomagnetic studies on the Hikurangi margin.- 5. Mechanics of rotation.- 6. Conclusions.- Rotations about Vertical Axes in Part of the New Zealand Plate- Boundary Zone, Theory and Observation.- 1. Introduction.- 2. Floating block model.- 3. New Zealand plate-boundary zone.- 4. Northern Marlborough domain.- 5. Southern Marlborough domain.- 6. Development of Marlborough domains.- 7. Conclusion.- Paleomagnetic Rotations in the Coastal A…