| Full text | |
| Author(s): |
Dragone, Gabriel N.
[1]
;
Bologna, Mauricio S.
[1]
;
Ussami, Naomi
[1]
;
Gimenez, Mario E.
[2, 3]
;
Alvarez, Orlando
[2, 3]
;
Klinger, Federico G. Lince
[2, 3]
;
Correa-Otto, Sebastian
[2, 3]
Total Authors: 7
|
| Affiliation: | [1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, Dept Geofis, Sao Paulo - Brazil
[2] Consejo Nacl Invest Cient & Tecn, Buenos Aires, DF - Argentina
[3] Univ Nacl San Juan, Fac Ciencias Exactas Fis & Nat, Inst Geofis Sismol Volponi IGSV, San Juan - Argentina
Total Affiliations: 3
|
| Document type: | Journal article |
| Source: | TECTONOPHYSICS; v. 811, JUL 20 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
A magnetotelluric survey comprising 18 broadband stations disposed along a 450 km-long profile was carried out at the transition between the Chaco-Parana (CPB) and the Parana (PB) intracratonic basins in northeastern Argentina. Three-dimensional inversions of the responses show that the CPB and southern PB lithospheres are resistive (similar to 10(3) Omega m) down to 120 km, but with distinct crustal and upper mantle electrical properties. Also, Bouguer gravity and density anomalies are positive at CPB, whereas they are negative at PB. We associate the CPB lithosphere with the Paleoproterozoic Rio Tebicuary craton and the southern PB lithosphere with an ancient and buried piece of craton, the Southern Parana craton. Geochemical data of mantle xenoliths from the Cenozoic alkaline/carbonatitic province within the Rio Tebicuary craton suggest a subcontinental lithospheric mantle affected by metasomatic processes, which explains its lower resistivity (reaching values as low as 300 Omega m) and higher density (\#Mg = 0.87). In contrast, the Southern Parana craton is more resistive (>10(3) Omega m) and less dense, suggesting a de-hydrated, depleted, and thicker craton. These cratons are separated by a crustal conductor (15 to 20 km depth; 1-10 Omega m) that we interpret as a southward continuation of a linear anomaly (Parana Axial Anomaly) defined in former induction studies within the PB in Brazil. Hence, we redefined the trace of this conductive lineament: instead of bending towards the Torres Syncline, it continues inside the CPB. We propose the lineament to be an Early Neoproterozoic suture zone that controlled the location of maximum subsidence in the intracratonic basins during the Paleozoic. In the Early Cretaceous, the Parana Axial Anomaly was the site of maximum extrusion and deposition of Serra Geral basalts. This anomaly separates compositionally distinct cratonic lithospheres along its path. Melting of this heterogeneous and enriched mantle created the Parana igneous province. (AU) | |
| FAPESP's process: | 12/06082-6 - The Paraná-Etendeka magmatic province in Brazil: temporal and petrologic relationships between the tholeiitic and alkaline magmatism and geodynamic implications |
| Grantee: | Excelso Ruberti |
| Support Opportunities: | Research Projects - Thematic Grants |
| FAPESP's process: | 09/54006-4 - A computer cluster for the Astronomy Department of the University of São Paulo Institute of Astronomy, Geophysics and Atmospheric Sciences and for the Cruzeiro do Sul University Astrophysics Center |
| Grantee: | Elisabete Maria de Gouveia Dal Pino |
| Support Opportunities: | Multi-user Equipment Program |