Long-wavelength magnetic anomalies as a source of information about deep crustal structure
Article Sidebar
Main Article Content
Abstract
The nature of long-wavelength magnetic anomalies (λ = 60–300 km) computed for the Ukrainian Shield from the original field by a continuation upward to a height of 10 km is studied. The correlation betweeen the regional anomalies, the crustal thickness and the topography of the Curie isotherm of magnetite is examined. The strongest correlation is established between the regional anomalies and the crustal thickness. Similar results have been obtained by us for the Baltic Shield and by D.H. Hall for the Canadian Shield. It is concluded that the entire lower crust is magnetized, the average magnetization being almost the same for all the ancient shields. These results have been used for the construction of a magnetic model of the Earth's crust. With some exceptions, the magnetization of the lower crust is found to be inhomogeneous and 5-10 times higher than that of the upper crust. Theoretical modelling and experimental results show a high magnetization in the entire sequence of blocks for the case of a thickened crust and, vice versa, weakly magnetized rocks correspond to a smaller thickness of the crust. The present approach may be of potential use for distinguishing and studying crust-upper mantle interaction areas as well as for predicting the topography of the Moho discontinuity.
ARK: https://n2t.net/ark:/88439/y092937
Permalink: https://geophysicsjournal.com/article/282
Article Details
Authors who publish with this journal as of Vol. 63 agree to the following terms:
a. Authors share the copyright with this journal in equal parts (50% to the journal, 50% to the lead author), and grant the journal right of first publication, with the work after publication simultaneously licensed under Creative Commons Attribution License CC BY-NC-ND 4.0 that allows others to share the work with an acknowledgment of the work's authorship and initial publication in this journal.
b. Authors may enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in this journal, and a reference to this copyright notice.
c. Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) during the submission process, as this can lead to productive exchanges and earlier and greater citation of published work and better sales of the copyright.
Author Self-archiving
Authors retain copyright and grant the Journal of Geophysics right of first publication, with the work three years after publication simultaneously licensed under the Creative Commons BY-NC-ND 4.0 License that allows others to share the work (with an acknowledgment of the work's authorship and initial publication in this journal), except for commercial purposes and for creating derivatives.
Authors can enter into separate, additional, but non-commercial contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository, but not publish it in a book), with an acknowledgment of its initial publication in this journal.
Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) before and during the submission process, as that can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
Additional Notes
This journal is one of a handful of scholarly journals that publish original scientific works under CC BY-NC-ND 4.0 - the only Creative Commons license affording the authors' intellectual property absolute worldwide protection.
Journal of Geophysics is published under the scholar-publishers model, meaning authors do not surrender their copyright to us. Instead, and unlike corporate publishers like Elsevier or Springer Nature that resell copyright to third-parties for up to $80,000 (per paper, per transaction!), the Journal of Geophysics authors share copyright equally with this journal.
Therefore, all the proceeds from reselling copyright to third parties get shared to equal parts (50% to the journal, 50% to the lead author). Under the Berne Convention, this protection is an inheritable right that lasts for as long as the rightsholder lives + 50 years.
By submitting to this journal, the lead author, on behalf of all co-authors, grants permission to this journal to represent all co-authors in negotiating copyright sales and collecting proceeds. The lead author should negotiate with his/her co-authors the modalities of distributing the lead author's portion of the proceeds. Usually, this is per pre-agreed percentage of each co-author's contribution to creating the copyrighted work. (more...)
References
Christencen, N.l., Fountain, D.M. (1975) Constitution of the lower continental crust based on experimental studies of seismic velocities in granulite. Geol. Soc. Am. Bull. 86:227-234
Dortman, N.B. (1976) Effect of thermodynamical conditions of formation on magnetic characteristics of the intrusive rocks (in Russian). In: Magnetic anomalies of the Earth's interior. Naukova
Dumka, Kiev
Green, A.G. (1976) Interpretation of project Magnet aeromagnetic profiles across Africa. Geophys. J. 44:203-228
Hall, D.H. (1974) Long-wavelength aeromagnetic anomalies and deep crustal magnetization in Manitoba and Northwestern Ontario, Canada. J. Geophys. 40:403-430
Kalyaev, G.I. (1976) The most ancient stage of continental crust formation (in Russian). Geofiz. Sbornik, No. 73:56-60
Krutikhovskaya, Z.A. (1976) Problems of creating the Earth's crust magnetic model for ancient shields (in Russian). Geofiz. Sb. No. 73:3-29
Krutikhovskaya, Z.A., Pashkevich, I.K., and Simonenko, T.N. (1973) Magnetic anomalies of Precambrian shields and some problems of their geological interpretation. Can. J. Earth Sci. 10:629-636
Krutikhovskaya, Z.A., Pashkevich, I.K. (1974) Magnetic field and structure of the Earth's crust for ancient shields (in Russian). Geofiz. Sb. No. 62:3-15
Krutikhovskaya, Z.A., Pashkevich, I.K. (1976) Is the crust of the ancient shields and platforms magnetized? (in Russian). Geofiz. Sb. No. 71:89-91
Kutas, R.I. (1976) Temperature distribution in the Earth's crust for the territory of the Ukrainian SSR(in Russian). Geofiz. Sb. No. 70:86-94
Kutas, R.I. (1977) A thermal model for the Earth's crust of the Ukrainian Shield along DSS line VIII (in Russian). Geofiz. Sb. No. 80 (In press)
Nalivkina, E.B. (1976) Petrological model of the Baltic Shield eastern part (in Russian). Geofiz. Sb. No. 73:46-55
Pashkevich, I.K. (1976) Procedure of distinguishing and interpretation of regional magnetic anomalies (In Russian). Geofiz. Sb. No. 73:30-36
Pavlenkova, N.I. (1973) Velocity fields and Earth's crust model (in Russian). Naukova Dumka, Kiev
Riddihough, R.P. (1972) Regional magnetic anomalies and geology in Fennoscandia. A discussion. Can. J. Earth Sci. 9:219-232
Semyonova, S.G. (1973) Relationship between physical properties, mineralogical composition and structural factors (in Russian). Geofiz. Razved., No. 57:128-136
Sollogub, V.B., Chekunov, A.V. (1975) Deep structure and Earth's crust evolution (in Russian). In: The Earth's physics problems in the Ukraine. Naukova Dumka, Kiev 118-141
Vogel, A., Lund, C.E. (1970) Combined interpretation of the Trans-Scandinavian seismic profile, section 2-3, University of Uppsala, Report 4, Uppsala