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| Titel |
Fault evolution in the Potiguar rift termination, equatorial margin of Brazil |
| VerfasserIn |
D. L. de Castro, F. H. R. Bezerra |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1869-9510
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| Digitales Dokument |
URL |
| Erschienen |
In: Solid Earth ; 6, no. 1 ; Nr. 6, no. 1 (2015-02-12), S.185-196 |
| Datensatznummer |
250115395
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| Publikation (Nr.) |
 copernicus.org/se-6-185-2015.pdf |
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| Zusammenfassung |
| The transform shearing between South American and African plates in the
Cretaceous generated a series of sedimentary basins on both plate margins.
In this study, we use gravity, aeromagnetic, and resistivity surveys to
identify architecture of fault systems and to analyze the evolution of the
eastern equatorial margin of Brazil. Our study area is the southern onshore
termination of the Potiguar rift, which is an aborted NE-trending rift arm
developed during the breakup of Pangea. The basin is located along the NNE
margin of South America that faces the main transform zone that separates
the North and the South Atlantic. The Potiguar rift is a Neocomian
structure located at the intersection of the equatorial and western South
Atlantic and is composed of a series of NE-trending horsts and grabens. This
study reveals new grabens in the Potiguar rift and indicates that stretching
in the southern rift termination created a WNW-trending, 10 km wide, and
~ 40 km long right-lateral strike-slip fault zone. This zone
encompasses at least eight depocenters, which are bounded by a
left-stepping, en echelon system of NW–SE- to NS-striking normal faults.
These depocenters form grabens up to 1200 m deep with a rhomb-shaped
geometry, which are filled with rift sedimentary units and capped by
postrift sedimentary sequences. The evolution of the rift termination is
consistent with the right-lateral shearing of the equatorial margin in the
Cretaceous and occurs not only at the rift termination but also as isolated
structures away from the main rift. This study indicates that the
strike-slip shearing between two plates propagated to the interior of one of
these plates, where faults with similar orientation, kinematics, geometry,
and timing of the major transform are observed. These faults also influence
rift geometry. |
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