کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6431462 | 1635167 | 2013 | 9 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Anomalous electrical structure in the northwestern Paraná Basin, Brazil, observed with broadband magnetotellurics Anomalous electrical structure in the northwestern Paraná Basin, Brazil, observed with broadband magnetotellurics](/preview/png/6431462.png)
The deep structure of the northern part of the Paraná Basin has been investigated through the analysis of a SW-NE magnetotelluric (MT) profile composed of 24 broadband stations with periods from 0.001 to â¼1000Â s that are regularly spaced â¼10Â km apart. The SW portion of the profile crosses a negative Bouguer anomaly with amplitudes of â¼20Â mGal. Our analyses show that there are two lithospheric domains with different gravity and electric conductivity properties. In the regularized two-dimensional MT inversion model the mid-to-lower crust in the SW part of the profile is almost two orders in magnitude more conductive compared to the NE portion. This difference in conductivity extends to the uppermost mantle depths, suggesting the existence of a major lithospheric discontinuity in the north-central Paraná Basin, locally coincident with the position of the Aporé River. We interpret this discontinuity as a juxtaposition of terranes with distinct natures and ages, possibly as result of tectonic accretion during the formation of Western Gondwana.
⺠We report a magnetotelluric survey in the northern Paraná Basin, SE Brazil. ⺠The conductivity model displays a lateral heterogeneity in the lithosphere. ⺠The electrical contrasts are likely due to the juxtaposition of tectonic terranes.
Journal: Journal of South American Earth Sciences - Volume 42, March 2013, Pages 74-82