Artículo
Abstract:
Palaeomagnetic data from samples collected in a rock sequence of tuffs and shales (Suri Formation), exposed in northwestern Argentina, indicate that the geomagnetic field had reversed polarity in Llanvirnian time. The samples from the top of the sequence also record, at least, an excursion of the geomagnetic field. The palaeomagnetic study carried out on samples collected in a rock sequence of shallow marine sediments of Late Precambrian age (La Tinta Formation), exposed in central-eastern Argentina, indicates that the geomagnetic field had alternating periods of normal and reversed polarity in that geological time. The positions of the palaeomagnetic poles for the Suri and La Tinta Formations are consistent with the interpretation that Gondwana was a unit as far back as Late Precambrian and with the occurrences of Upper Ordovician and Upper Precambrian glacial deposits across Africa and Australia, respectively. They do not, however, exclude models involving the opening and closing of minor seas. Particularly, the position of La Tinta pole is consistent with the interpretation which suggests that the sediments of this formation and those of the Nama Group (Africa) were deposited in a common shallow marine basin. © 1980, Society of Geomagnetism and Earth, Planetary and Space Sciences. All rights reserved.
Registro:
| Documento: | Artículo |
| Título: | Palaeomagnetism of Lower Ordovician and Upper Precambrian Rocks from Argentina |
| Autor: | Valencio, D.A. |
| Filiación: | Departamento de Ciencias Geológicas, Universidad de Buenos Aires, Ciudad Universitaria, Pabellon 2, Buenos Aires, Argentina |
| Año: | 1980 |
| Volumen: | 32 |
| Página de inicio: | SIII71 |
| Página de fin: | SIII75 |
| DOI: | http://dx.doi.org/10.5636/jgg.32.Supplement3_SIII71 |
| Título revista: | Journal of geomagnetism and geoelectricity |
| Título revista abreviado: | J. Geomagn. Geoelectr. |
| ISSN: | 00221392 |
| Registro: | https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_00221392_v32_n_pSIII71_Valencio |
Referencias:
- Dalla Salda, L., (1979) Nama and La Tinta Groups—a common Southern Africa–Argentine basin?, , 16th Annual Report Chamber of Mines, Precambrian Research Unit, Univ. of Cape Town in press
- Du Toit, A., (1927) A geological comparison of South America with South Africa with paleontological contribution, p. 381. , F. R. Cowper Reed, Wash. Pub. Carneg. Inst
- Kirschvink, J.L., The Precambrian-Cambrian boundary problem: paleomagnetic directions from the Amadeus Basin, Central Australia (1978) Earth Planet. Sci. Lett, 40, pp. 91-100
- Khramov, A.N., Pechersky, D.M., Molostovsky, E.A., Rodionov, V.P., (1978) Palaeomagnetic scale for the Mesozoic and Palaeozoic of the USSR, (56). , Inter-Union Commission on Geodynamics, Workshop on Magnetostratigraphy and Geodynamics, Leningrad, 1978, ICG Scientific Report in press
- McElhinny, M.W., Embleton, B.J.J., Precambrian and Early Palaeozoic palaeomagnetism in Australia (1976) Phil. Trans. R. Soc. Lond, A280, pp. 417-431
- Valencio, D.A., Vilas, J.F., Mendia, J.E., Palaeomagnetism and K-Ar ages of Lower Ordovician and Upper Silurian-Lower Devonian rocks from northwestern Argentina (1980) Geophys. J. R. Astr. Soc, 62 (1), pp. 27-40
- Valencio, D.A., Sinito, A.M., Vilas, J.F., Palaeomagnetism of Late Precambrian rocks of La Tinta Formation, Argentina (1980) Geophys. J. R. Astr. Soc, 62 (3), pp. 563-576
- Vilas, J.F., Valencio, D.A., Palaeomagnetism and K-Ar age of the Upper Ordovician Alcaparrosa Formation, Argentina (1978) Geophys. J. R. Astr. Soc, 55, pp. 143-154
Citas:
---------- APA ----------
(1980) . Palaeomagnetism of Lower Ordovician and Upper Precambrian Rocks from Argentina. Journal of geomagnetism and geoelectricity, 32, SIII71-SIII75.http://dx.doi.org/10.5636/jgg.32.Supplement3_SIII71
---------- CHICAGO ----------
Valencio, D.A. "Palaeomagnetism of Lower Ordovician and Upper Precambrian Rocks from Argentina" . Journal of geomagnetism and geoelectricity 32 (1980) : SIII71-SIII75.http://dx.doi.org/10.5636/jgg.32.Supplement3_SIII71
---------- MLA ----------
Valencio, D.A. "Palaeomagnetism of Lower Ordovician and Upper Precambrian Rocks from Argentina" . Journal of geomagnetism and geoelectricity, vol. 32, 1980, pp. SIII71-SIII75.http://dx.doi.org/10.5636/jgg.32.Supplement3_SIII71
---------- VANCOUVER ----------
Valencio, D.A. Palaeomagnetism of Lower Ordovician and Upper Precambrian Rocks from Argentina. J. Geomagn. Geoelectr. 1980;32:SIII71-SIII75.http://dx.doi.org/10.5636/jgg.32.Supplement3_SIII71
