DOI

Lately data have been getting more and more, indicating an unusual, abnormal state of the magnetic field at the boundary of the Precambrian and Phanerozoic. This fact limits significantly the possibility on employing the paleomagnetic approach for creating various paleoreconstructions in this time interval, and it allows a better understanding of the evolution of the Earth's magnetic field. Until recently, there was no exact binding of Lower Cambrian sections bearing an anomalous paleomagnetic record to the chronostratigraphical chart, which did not allow to obtain adequate estimates of the duration of the anomalous state of the magnetic field. In this study we present the results of a paleomagnetic study of the Lower Cambrian terrigenous-carbonate rocks of the Udzha and Anabar uplifts (Emyaksa and Medvezh Formations). New evidence has been obtained of the anomalous the paleomagnetic record in these rocks, which manifests itself in the objective existence of two significantly different directions of the high-temperature magnetization components, the formation of which cannot be explained by a later remagnetization. U-Pb dating of detrital zircons constraints the maximum depositional age of the Manykay and Emyaksa Formations on ~520 Ma, what pointing to Atdaban age of studied succession in combination with the faunistic characteristic of the upper part of the Emyaksa Formation. The age constraits obtained indicate on a specific paleomagnetic record, due to the peculiarities of the generation of the geomagnetic field of the terminal Precambrian - Early Cambrian, can be traced back to the Atdaban age, including.

Переведенное названиеPaleomagnetism and provenance of the lower Cambrian sedimentary rocks of the udzha uplift (north of the Siberian platform)
Язык оригиналарусский
Число страниц34
ЖурналВестник Санкт-Петербургского университета. Науки о Земле
Том65
Номер выпуска3
DOI
СостояниеОпубликовано - авг 2020

    Предметные области Scopus

  • Геология
  • Планетоведение и науки о земле (все)

    Области исследований

  • Detrital zircons, East Siberian platform, Lower Cambrian, Manykay formation, Paleomagnetism, Source rocks, U-Pb dating

ID: 70502644