Restoring paleomagnetic data in complex superposed folding settings: The Boltaña anticline (Southern Pyrenees)

2016 ◽  
Vol 671 ◽  
pp. 281-298 ◽  
Author(s):  
T. Mochales ◽  
E.L. Pueyo ◽  
A.M. Casas ◽  
A. Barnolas
Keyword(s):  
Paleomagnetic Data ◽  
Superposed Folding

PALEOMAGNETIC DATA FROM STONEMAN LAKE, ARIZONA PLACING CONSTRAINTS ON THE EVOLUTION OF TERRESTRIAL CLIMATE AND VEGETATION THROUGH THE MID PLEISTOCENE TRANSITION

2019 ◽  
Author(s):  
Michael Petronis ◽  
◽  
R. Scott Anderson ◽  
Peter J. Fawcett ◽  
Spencer E. Staley ◽  
...  
Keyword(s):  
Paleomagnetic Data

scholarly journals Paleomagnetic data support Early Permian age for the Abor Volcanics in the lower Siang Valley, NE India: Significance for Gondwana-related break-up models

2012 ◽  
Vol 50 ◽  
pp. 105-115 ◽  
Author(s):  
Jason R. Ali ◽  
Jonathan C. Aitchison ◽  
Sam Y.S. Chik ◽  
Alan T. Baxter ◽  
Scott E. Bryan
Keyword(s):  
Paleomagnetic Data ◽  
Early Permian ◽  
Data Support ◽  
Ne India ◽  
Break Up

A Kinematic Reconstruction of Jurassic ocean spreading from the ophiolites of California, the western U.S. using structural geology and paleomagnetism.

2021 ◽  
Author(s):  
Cemil Arkula ◽  
Nalan Lom ◽  
John Wakabayashi ◽  
Grant Rea-Downing ◽  
Mark Dekkers ◽  
...  
Keyword(s):  
North America ◽  
Relative Position ◽  
North American ◽  
Fault System ◽  
Paleomagnetic Data ◽  
Geochemical Data ◽  
Ophiolite Belt ◽  
The North ◽  
Western Us ◽  
Jurassic Ophiolites

<p>The western edge of the North America plate contains geological records that formed during the long-lived convergence between plates of the Panthalassa Ocean and North America. The geology of different segments along western North America indicates different polarities (eastward and westward) for subducted slabs and thereby various tectonic histories and settings. The western United States (together with Mexico) plays a key role in this debate, many geologic interpretations assume continuous eastward subduction in contrast to observations within proximal geologic segments and tomographic images of the lower mantle below North America and the eastern Pacific Ocean which suggest a more complex subduction history. In this study, we aim to evaluate the plate tectonic setting in which the Jurassic ophiolites of California formed. Geochemical data from these ophiolites suggest that they formed above a nascent intra-oceanic or continental margin subduction zone. We first developed a kinematic reconstruction of the western US geology back to the Jurassic based on published structural geological data. Importantly, we update the reconstruction of the various branches of the San Andreas fault system to determine the relative position of the ophiolite fragments and adopt a previous restoration of Basin and Range extension which we expand northward towards Washington state. We then reconstruct North American margin deformation associated with Cretaceous to Paleogene shortening and strike-slip faulting. We find no clear candidates in the geological record that may have accommodated major subduction between the Jurassic ophiolite belt and the North American margin and consequently concur with the school of thought that considers that the ophiolite belt, as well as the underlying subduction-accretionary Franciscan Complex, likely formed in the North American fore-arc. We collected paleomagnetic data to reconstruct the spreading direction of the Jurassic Californian ophiolites, by providing new paleomagnetic data from sheeted dykes of the Josephine and Mt. Diablo Ophiolites. These suggest a NE-SW paleo-ridge orientation, oblique to the North American margin which may be explained by partitioning of a dextral component of subduction obliquity relative to North America. We used this spreading direction in combination with published ages of the ophiolites and our restoration of the relative position of these ophiolites prior to post-Jurassic deformation to construct a ridge-transform system at which the Jurassic ophiolites accreted. The results will be used to evaluate which parts of the subduction systems that existed in the eastern Panthalassa Ocean may reside in the western US, and which parts may be better sought in the northern Canadian Segment or/and in the southern Caribbean region.</p>

Geochronological and paleomagnetic studies of small carbonatite intrusions of the Udzha uplift (Tomtor massif, northeast of the Siberian platform)

2021 ◽  
Author(s):  
Aleksandr Pasenko ◽  
Ivanov Alexey ◽  
Malyshev Sergey ◽  
Travin Alexey
Keyword(s):  
Siberian Platform ◽  
Conclusive Evidence ◽  
Snowball Earth ◽  
Paleomagnetic Data ◽  
Russian Science ◽  
Virtual Geomagnetic Pole ◽  
River Bank ◽  
High Temperature Component ◽  
Geomagnetic Pole ◽  
Temperature Component

<p>Paleomagnetic data obtained from Neoproterozoic glacial and glacier-associated sedimentary rocks indicate that they were formed at near equatorial latitudes. Based on these data, the Snowball Earth hypothesis was proposed [Kirschvink, 1992]. According to this hypothesis, during the Neoproterozoic glaciations, the entire planet (including the oceans) was completely covered with ice. Although evidence is emerging that does not support this hypothesis, there is still no conclusive evidence that it is not true [Sansjofre et al., 2011].</p><p>It is worth noting that the Snowball earth hypothesis is based on paleomagnetic data. At the same time, the available paleomagnetic data for the Neoproterozoic-Early Cambrian [Meert, Van der Voo, 2001; Shatsillo et al, 2005; Abrajevitch, Van der Voo, 2010; Pavlov et al., 2018] difficult to interpret in terms of the Geocentric Axial Dipole hypothesis. This imposes serious restrictions on the possibility of correctly constructing paleomagnetic reconstructions.</p><p>For the development and testing of a model of the geomagnetic field of the Neoproterozoic, it is necessary to obtain a lot of high-quality paleomagnetic data. Data from well-dated magmatic bodies are especially valuable.</p><p>Within the framework of this work, we obtained paleomagnetic data from three carbonatite dikes (7 to 30 cm thickness) exposed in the Udzha river bank on the Udzha uplift in the northeastern part of the Siberian platform. These dikes are associated with the large alkaline Tomtor massif located 15 km to the west. Ar/Ar dating of phlogopite megacrysts gives an intrusion age of the dikes of 706.1±8.8 Ma. Coordinates of the virtual geomagnetic pole, calculated from the direction of the high-temperature component of magnetization: Φ=-20.7°; Λ=88.6°; Α95=3.4°.</p><p>Our report will present preliminary interpretation of these data, as well as their comparison with paleomagnetic data on close-aged objects in Siberia.</p><p><em>The research was supported by the Russian Science Foundation grant (19-77-10048).</em></p><p>References:</p>

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