Brittle reactivation of mylonitic fabric and the origin of the Cenozoic Rio Santana Graben, southeastern Brazil

Gontijo-Pascutti, Ambrosina; Bezerra, Francisco H.R.; Terra, Emanuele F. La; Almeida, Júlio

doi:10.1016/j.jsames.2009.06.007

Cited by 28 publications

(19 citation statements)

References 55 publications

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“…Ferrari (2001) documented NW-SE-directed extension between Early and Late Oligocene time in the Guanabara graben. Gontijo-Pascutti et al (2010) described dip-slip and strike-slip reactivation of Precambrian fabrics in the neighboring Rio Santana graben that began in the Paleogene and continued until Where taper is sharp, the offshore load lies relatively close to the ILE. Tensile bending stress and high GPE were probably present near the coastlines immediately following thinning-phase necking, creating conditions favorable for normal fault formation or reactivation and consequent footwall uplift.…”

Section: Stress and Modes Of Tapermentioning

confidence: 99%

“…As in Scandinavia, the present-day stress field in much of Southeast Brasil is generally considered slightly compressive (Riccomini et al, 1989;Riccomini & Assumpção, 1999;Salomon et al, 2014). However, landscapes and neotectonic deformation that include components of normal faulting are also well documented (e.g., Riccomini et al, 1989;Riccomini & Assumpção, 1999;Bezerra & Vita-Finzi, 2000;Fortes et al, 2005;Gontijo-Pascutti et al, 2010;Silva & Mello, 2011). In Northeast Brasil, neotectonic faulting caused systematic uplift and subsidence that may have been largely responsible for shaping today's landscapes (Bezerra et al, 2006(Bezerra et al, , 2008.…”

Section: The Model Abroadmentioning

confidence: 99%

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Some remarks on the earthquakes of Fennoscandia: A conceptual seismological model drawn from the perspective of hyperextension

Redfield¹,

Osmundsen²

2015

NJG

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To a first order, patterns of Fennoscandia's seismicity reflect the benchmark domain boundaries of its Mesozoic rifted margin. Three distinct belts of earthquakes strike sub-parallel to the generalized line of breakup. The outermost seismic belt (SB1) marks the Taper Break (TB), or the zone of flexural coupling/decoupling between the distal (seaward) and proximal/necking (landward) domains. A coastal belt (SB2) follows the Innermost Limit of Extension, defined as the onset of 39 km-thick crystalline continental crust. An interior belt (SB3) follows the Hinterland Break in Slope, or the landward limit of the Scandinavian rifted margin. Between each belt, large portions of the necking, proximal, and hinterland domains are seismically quiescent. Evaluation of the 'Cumulative Seismic Moment' (CSM w ) per unit area indicates that the release of seismic energy is asymmetric. Although some of Fennoscandia's largest seismic events occur in the dominantly Proterozoic to Archean lithosphere of the eastern craton, 80% of Fennoscandian CSM w maps to the domain boundaries of the western rifted margin. CSM w energy tends to be highest at the TB and decreases system atically towards the continental interior.As proposed by many previous studies, a first-order spatial correlation between Scandinavia's offshore earthquake belt and voluminous, geo logically rapid, sedimentary loading during the Neogene period is evident. However, the presence of thinned, faulted crystalline basement is also a very important factor behind Scandinavia's offshore seismicity. Where the Neogene deposits are at their thickest the underlying crust is dominantly oceanic; CSM w is lower per unit area there than where lesser Plio-Pleistocene loading impacts continental crust that was fully prepared by Mesozoic necking and hyperextension. CSM w data suggest that the 'strength' of the TB and the continental margin's distal domain is significantly less than that of relatively young (ca. 54 Ma) oceanic lithosphere. Our data imply that ridge push does not contribute significantly to Fennoscandia's seismicity. Rather, we find that thin-plate bending stresses stemming from offshore depositional loading conspire with unbuttressed Gravitational Potential Energy (GPE), onshore erosion, and post-glacial isostatic rebound to generate Fennoscandia's earthquakes.We present a conceptual seismological model for Fennoscadia that is consistent with modern hypotheses of extended margin evolution, including post-breakup reactivation by footwall uplift in regions adjacent to sharp crustal taper. Illustrated by simple concepts of elastic thin-plate theory, the model honors our conclusion that Fennoscandian seismicity is principally the product of locally derived stress fields and that far field stress from the oceanic domain is unlikely to penetrate deeply into a hyperextended continental margin. It predicts the locations of the observed seismic belts and seismic gaps with the mathematics of thin-plate bending. It describes how the outer seismic belt will remain localized in the...

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Section: Stress and Modes Of Tapermentioning

confidence: 99%

Section: The Model Abroadmentioning

confidence: 99%

Some remarks on the earthquakes of Fennoscandia: A conceptual seismological model drawn from the perspective of hyperextension

Redfield¹,

Osmundsen²

2015

NJG

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“…Preexisting structures, along with early phases of rifting, can exert a considerable influence over the distribution of fault activity and the geometry and evolution of syn‐rift depocenters during rifting. Pervasive basement fabrics can directly control the geometry of faults and the (rift) basins they bound (e.g., Daly et al, ; Fazlikhani et al, ; Gontijo‐Pascutti et al, ; Morley et al, ; Paton & Underhill, ; Phillips et al, ; Phillips et al, ; Salomon et al, ; Skyttä et al, ; Vasconcelos et al, ). Discrete structures may also locally perturb the regional stress field, causing faults to strike oblique to the regional extension direction (Corti, ; Corti et al, ; Morley, , ; Philippon et al, ; Rotevatn et al, ; Samsu et al, ).…”

Section: Introductionmentioning

confidence: 99%

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

et al. 2019

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The northern North Sea rift evolved through multiple rift phases within a highly heterogeneous crystalline basement. The geometry and evolution of syn-rift depocenters during this multiphase evolution and the mechanisms and extent to which they were influenced by preexisting structural heterogeneities remain elusive, particularly at the regional scale. Using an extensive database of borehole-constrained 2D seismic reflection data, we examine how the physiography of the northern North Sea rift evolved throughout late Permian-Early Triassic (RP1) and Late Jurassic-Early Cretaceous (RP2) rift phases, and assess the influence of basement structures related to the Caledonian orogeny and subsequent Devonian extension. During RP1, the location of major depocenters, the Stord and East Shetland basins, was controlled by favorably oriented Devonian shear zones. RP2 shows a diminished influence from structural heterogeneities, activity localizes along the Viking-Sogn graben system and the East Shetland Basin, with negligible activity in the Stord Basin and Horda Platform. The Utsira High and the Devonian Lomre Shear Zone form the eastern barrier to rift activity during RP2. Toward the end of RP2, rift activity migrated northward as extension related to opening of the proto-North Atlantic becomes the dominant regional stress as rift activity in the northern North Sea decreases. Through documenting the evolving syn-rift depocenters of the northern North Sea rift, we show how structural heterogeneities and prior rift phases influence regional rift physiography and kinematics, controlling the segmentation of depocenters, as well as the locations, styles, and magnitude of fault activity and reactivation during subsequent events.

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“…Diversos estudos têm apresentado quadros que sintetizam a evolução tectonossedimentar da região Sudeste do Brasil durante o Cenozoico, mostrando, particularmente, a atuação de mecanismos neotectônicos Salvador, 1994;Salvador e Riccomini, 1995;Mello, 1997;Mello et al, 1999;Riccomini e Assumpção, 1999;Ferrari, 2001;Modenesi--Gauttieri, Hiruma, Riccomini, 2002;Sarges, 2002;Albuquerque, 2004;Riccomini, Sant´Anna, Ferrari, 2004;Sanson, 2006;Gontijo-Pascutti et al, 2010). Segundo Hasui (1990), estes mecanismos neotectônicos enquadram-se em um modelo de tectônica ressurgente, ou seja, aproveitando-se parcialmente de planos de fraqueza desenvolvidos durante fases tectônicas anteriores.…”

Section: Introductionunclassified

Reativações neotectônicas na Zona de Cisalhamento do Rio Paraíba do Sul (sudeste do Brasil)

Silva

Mello

2011

Geol. USP, Sér. cient.

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Brittle reactivation of mylonitic fabric and the origin of the Cenozoic Rio Santana Graben, southeastern Brazil

Cited by 28 publications

References 55 publications

Some remarks on the earthquakes of Fennoscandia: A conceptual seismological model drawn from the perspective of hyperextension

Some remarks on the earthquakes of Fennoscandia: A conceptual seismological model drawn from the perspective of hyperextension

The Influence of Structural Inheritance and Multiphase Extension on Rift Development, the NorthernNorth Sea

Reativações neotectônicas na Zona de Cisalhamento do Rio Paraíba do Sul (sudeste do Brasil)

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