Tectonic implications of a paleomagnetic study of the Sarmiento Ophiolitic Complex, southern Chile

2008 ◽  
Vol 452 (1-4) ◽  
pp. 29-41 ◽  
Author(s):  
A.E. Rapalini ◽  
M. Calderón ◽  
S. Singer ◽  
F. Hervé ◽  
U. Cordani
Keyword(s):  
Southern Chile ◽  
Tectonic Implications ◽  
Paleomagnetic Study ◽  
Ophiolitic Complex

scholarly journals Remagnetization of Upper Jurassic limestones from the Danubian Unit (Southern Carpathians, Romania): tectonic implications

2012 ◽  
Vol 63 (6) ◽  
pp. 453-461 ◽  
Author(s):  
Panaiotu Cristian G. ◽  
Panaiotu Cristina E. ◽  
Lazăr Iuliana
Keyword(s):  
Remanent Magnetization ◽  
Upper Jurassic ◽  
Relative Rotation ◽  
Clockwise Rotation ◽  
Magnetization Component ◽  
Diagenetic Processes ◽  
Tectonic Implications ◽  
Paleomagnetic Study ◽  
Normal Polarity ◽  
Southern Carpathians

Abstract We present a pioneering paleomagnetic study on Upper Jurassic limestones from the Danubian Unit (Southern Carpathians, Romania). Thermal and alternating field demagnetizations were applied to define the characteristic remanent magnetization component in all six localities (81 samples). All samples have a normal polarity characteristic remanent magnetization. Negative regional and local fold tests suggest that this remanent magnetization is in fact a remagnetization produced by late diagenetic processes. The studied limestones were probably remagnetized during the collision of the Getic Unit and Danubian Unit which took place during the long normal polarity Chron C34 (82-118 Ma). The area mean direction (D = 75.5°, I = 50.0°, α95 = 10.2°, k = 44) implies about 75° clockwise rotation post remagnetization. Our paleomagnetic results further indicate the absence of significant relative rotation between the Getic Unit and the Danubian Unit during the Cenozoic.

A paleomagnetic study of Tertiary formations from the Kyrgyz Tien-Shan and its tectonic implications

1993 ◽  
Vol 98 (B6) ◽  
pp. 9571 ◽  
Author(s):  
J.-C. Thomas ◽  
H. Perroud ◽  
P. R. Cobbold ◽  
M. L. Bazhenov ◽  
V. S. Burtman ◽  
...  
Keyword(s):  
Tien Shan ◽  
Tectonic Implications ◽  
Paleomagnetic Study

Petrological Features and Magnetic Properties of Pillow Lavas from the Thetford Mines Ophiolite (Quebec)

1975 ◽  
Vol 12 (8) ◽  
pp. 1406-1420 ◽  
Author(s):  
M. K. Seguin ◽  
R. Laurent
Keyword(s):  
Remanent Magnetization ◽  
Outer Part ◽  
Detailed Examination ◽  
Intermediate Zone ◽  
Chemical Zoning ◽  
Fine Grained ◽  
Pillow Lavas ◽  
Paleomagnetic Study ◽  
Magnetic Signature ◽  
Ophiolitic Complex

A detailed examination was made to evaluate the variations of the remanent magnetization and magnetic susceptibility through four ophiolitic pillow lavas of Cambrian age. These pillowed metabasalts, which are covered by a thin layer of cherty argillite, derive from an olivine tholeiite of probable oceanic origin. They have been metamorphosed in the greenschist facies under a regime of low pressure, moderate temperature, and in the presence of water but absence of significant stress. They still display their primary structural zoning characterized by a thin outer shell, a much wider globulitic intermediate zone, and a porphyritic core. Morphologies of quenched microphenocrysts of olivine and plagioclase are well preserved.The magnetization resides in very fine-grained magnetite and, in spite of a very low remanent magnetization, the primary magnetic imprint appears to be still discernible. Remanent magnetization and Koenigsberger ratio vary from the pillow margin to its center in a fashion similar to the magnetic signature of some recent and fresh oceanic basalts. The magnetic zoning matches the textural, mineralogical, and chemical zoning characteristic of these pillow lavas. We found also that the N.R.M. vector is consistent and relatively stable within the pillow inner part of the intermediate zone and the outer part of the core and therefore that samples from these zones can be used for a regional paleomagnetic study of the ophiolitic complex.

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