Download or read book Paleomagnetic Quantification of Neogene Block Rotations Within an Active Transtensional Plate Boundary Baja California Sur Mexico written by Josef Weber and published by . This book was released on 2012 with total page 137 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetic Rotations and Continental Deformation written by Catherine Kissel and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book A Paleomagnetic Investigation of Vertical axis Rotations in Coastal Sonora Mexico written by Scott William Herman and published by . This book was released on 2013 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: These rotations occurred after 12 Ma and largely prior to 9 Ma, thus falling into the Proto-Gulf period. Such large-scale rotations lend credence to the theory that the area inboard of Baja California was experiencing transtension during the Proto-Gulf period, rather than the pure extension that would be the result of strain partitioning between Sonora and the Tosco-Abreojos fault offshore Baja California.
Download or read book Large Coherent Block Versus Microplate Rotation of the Western Transverse Range written by Daniel Schwartz and published by . This book was released on 2019 with total page 39 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within the last 30 million years, the Southern California plate boundary has transitioned from a region of plate collision and subduction to a right-lateral translational boundary. This transition created many of the geologic features that are observed today along the Inner California Borderlands (ICB), including the Western Transverse Range Province (WTR). The WTR has long been considered a large coherent block (~200 by 100 km) that underwent 90-100 degrees of clockwise rotation in the early Neogene as a result of right-lateral transform motion along the margin in a process characterized as "book-shelf" faulting. Directional paleomagnetic data have been employed to support the hypothesis of coherent rotation of 'books', here referred to as a 'large coherent block'. As the data collected in this region vary in quality, age, and locality, we set out to test how well the data support the large coherent block rotation hypothesis of the WTR when viewed as a composite. If the large coherent block rotation model is correct, it predicts the paleomagnetic directions of the same age within the WTR should record the same amount of rotation. To test this, we have compiled a large set of directional paleomagnetic data from relevant published papers, updating the age constraints to a consistent time scale where possible. By re-examining directional paleomagnetic data from same-age rocks within the WTR, our compilation shows different amounts of rotation across the WTR from formations that are similar in age. The directional paleomagnetic data are therefore inconsistent with the prediction of a large coherent block rotation model. We propose an alternative model for the deformation of the WTR, one that is consistent with paleomagnetic data from the region. In our model, rather than a single large block rotating coherently, many micro-plates that range from kilometers to tens of kilometers rotated individually, accommodating numerous right-lateral fault displacement. Our analog for the deformation of the WTR is a garnet schist, where the "garnets" are the microplates rotated by bounding right-lateral shear zones.
Download or read book Paleomagnetic Determination of Vertical axis Block Rotation and Magnetostratigraphy in the Mecca Hills and Coachella Valley California written by Cassidy Wade Dimitroff and published by . This book was released on 2015 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Plate Reconstruction from Paleozoic Paleomagnetism written by Rob Van der Voo and published by American Geophysical Union. This book was released on 1984 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetic Determination of Vertical Axis Block Rotation Near the Doty Fault in Southwestern Washington written by Charles C. Linneman and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper I present the results of paleomagnetically derived vertical axis rotations (VARs) of sites in two different flows of the Columbia River Basalt (CRB) - the 16 Ma Sentinel Bluffs member of the Grande Ronde flow and the 12 Ma Pomona Member of the Packsack Lookout - near the Doty fault in southwestern Washington. In two field seasons, I collected 99 cores from 14 sites, 11 in the Grande Ronde flow and three in the Pomona member flow. Of the 227 specimens that I demagnetized, 212 had well-defined magnetic directions. Positive fold and reversal tests results confirm the primary magnetization in both flows of the CRB, which is carried by magnetite and titanomagnetite. Using virtual geomagnetic poles (VGPs), I compared the tectonically corrected site mean directions from this study against reference directions measured in the same lithologies in the stable eastern Washington which has had little rotation since the Miocene. The resulting VARs in the Grande Ronde flow show a large range of rotations, from 68° counterclockwise (CCW) to 9.6° clockwise (CW) (Table 4), with an average CCW rotation of 22.3°. The Pomona Member sites all show CCW rotation between 0.5° and 2.5°, with an average CCW rotation of 2.1°. Previous paleomagnetic regional studies have consistently found an approximately 14-16° CW rotation in CRBs located on the forearc block. The CCW rotations of the CRBs adjacent the Doty fault suggest that fault activity, specifically sinistral strike-slip motion, occurred between 16 and 12 Ma, and possibly in the time since then. I hypothesize that an escape structure or wrench zone may be present in the region due to the concentrated, homogeneous stress present as the rotating Oregon-Washington forearc block squeezes the Puget lowlands block against the Canadian coast mountains. I propose that significant additional paleomagnetic research is needed in the area to determine the extent of the area with CCW rotation. This will also help create a more resolved map of where the boundaries of the rotating blocks are, how they may be rotating in relation to one another, and to help map the network of smaller faults facilitating the rotations.
Download or read book Neogene to Recent Tectonic Evolution of the Central Mediterranean written by Charon Estelle Duermeijer and published by . This book was released on 1999 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetology written by Aleksey N. Khramov and published by Springer. This book was released on 1987-10-15 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores the basic principles and methods of paleomagnetology and gives a systematic description of paleomagnetic phenomena such as geomagnetic reversals, paleosecular variations, long-term intensity changes and apparent polar wandering paths. Special emphasis is laid on results obtained from research work done in the Soviet Union. Together with data from other parts of the world they allow the critical discussion of aspects of magnetostratigraphy, plate tectonics and accretion tectonics. In diesem Buch werden grundlegende Fragen der Paläomagnetologie und des Paläomagnetismus abgehandelt. Durch die Einbeziehung zahlreicher Daten aus der Sowjetunion werden Probleme der Magnetostratigraphie sowie der Platten- und Akkretionstektonik kritisch beleuchtet.
Download or read book Paleomagnetic Analysis of Miocene Basalt Flows in the Tehachapi Mountains California written by Jeffrey B. Plescia and published by . This book was released on 1994 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt: New paleomagnetic directions and 40AR/39AR extrusion ages from Miocene basalt flows on the north flank of the Tehachapi Mountains, southern California.
Download or read book Paleomagnetic Study of Mid tertiary Rocks in the Northeastern Caribbean Investigation of Suspected Tectonic Block Rotations written by Jaime Feliciano and published by . This book was released on 1993 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetism of the Monterey Formation in the Western Transverse Ranges California written by John Scott Hornafius and published by . This book was released on 1984 with total page 482 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Palaeomagnetism and Plate Tectonics written by M. W. McElhinny and published by . This book was released on 1973-02 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetism and Plate Tectonics written by Jean Francheteau and published by . This book was released on 1970 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Paleomagnetism and plate tectonics are combined in a new procedure for producing paleogeographic reconstructions of the evolution of present day world geography from proto-continents. For each geologic epoch, the continents are first subjected to rotations relative to each other from the data of plate tectonics, then another rotation is carried out with respect to the Earth's spin axis by swinging the virtual paleomagnetic poles to the present north pole in a single rotation. The new method checks Bullard's reconstruction of the continents surrounding the Atlantic Ocean which was accomplished by computer fitting of their continental shelves. (Author).
Download or read book Methods in Palaeomagnetism written by D.W. Collinson and published by Elsevier. This book was released on 2013-10-22 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methods in Paleomagnetism covers the proceedings of the NATO Advanced Study Institute on Paleomagnetic Methods, held in the Physics Department of the University of Newcastle upon Tyne on April 1-10, 1964. The book focuses on apparatus and techniques used in paleomagnetism and rock magnetism. The selection first offers information on sampling techniques in the field and measurement of natural remanent magnetization. Discussions focus on ballistic and spinner magnetometers; paleomagnetic sampling with a portable coring drill; portable apparatus for collecting small oriented cores; and portable field-sampling equipment. The book also takes a look at procedures to test the stability of magnetization, as well as physical properties of demagnetization; thermal demagnetization by the continuous method; and apparatus for thermal demagnetization by the progressive method. The text ponders on measurement of isotropic and anisotropic susceptibility and magnetic measurements in applied fields. Topics include preliminary account of a refined technique for magnetic susceptibility anisotropy measurement of rocks; errors in anisotropy measurements with the torsion balance; and measurement of the anisotropy of the susceptibility with an astatic magnetometer. The selection is a valuable reference for readers interested in paleomagnetism.
Download or read book A Paleomagnetic Paleolatitude Determination from the Upper Cretaceous Units of the Gold Beach Terrane Southwest Coastal Oregon written by Noel Liner and published by . This book was released on 2005 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Paleomagnetism written by Robert F. Butler and published by Wiley-Blackwell. This book was released on 1992 with total page 319 pages. Available in PDF, EPUB and Kindle. Book excerpt:
