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Fabrizio Balsamo - One of the best experts on this subject based on the ideXlab platform.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

Aleksandra Smyraksikora - One of the best experts on this subject based on the ideXlab platform.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

Mark Joseph Mulrooney - One of the best experts on this subject based on the ideXlab platform.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

Luís Kennedy Andrade De ,sousa - One of the best experts on this subject based on the ideXlab platform.

  • Análise da reativação de falhas normais através da modelagem física com o uso do particle image velocimetry
    2016
    Co-Authors: Luís Kennedy Andrade De ,sousa
    Abstract:

    A modelagem analógica, desde o século XIX, vem sendo usada para simular estruturas geológicas com o objetivo de entender os mecanismos que controlam sua geometria e cinemática. O uso desta ferramenta na indústria do petróleo, para ajudar a interpretações sísmicas e, principalmente, para procurar armadilhas estruturais, contribuíram para difundir o uso desta ferramenta na literatura. Estudos envolvendo a modelagem analógica de inversão de bacias são desenvolvidos para melhorar o entendimento dos fatores que influenciam na reativação das estruturas pré-existentes, bem como sua geometria. Neste trabalho, procurou-se analisar a construção da arquitetura estrutural de um modelo de sistemas de falhas que sofre inversão positiva, e analisar a relação entre a geração de novas falhas e a reativação das falhas normais pré- existentes, durante um evento contracional. Adicionalmente, efetuou-se a análise do comportamento e distribuição do strain ao longo do processo deformacional a partir de imagens obtidas e processadas pelo sistema Particle Image Velocimetry (PIV). Foram estudados duas séries de experimentos: i) Série I: Analisou-se a geração de falhas associadas a geração de uma falha lístrica principal e sua reativação durante a inversão cinemática. Nesta série, dois tipos de modelos foram realizados: um com a falha lístrica, ortogonal a direção de tração e compressão (Série IA), e no outro a falha lístrica foi oblíqua (“α” = 80º) (Série IB). A configuração estrutural final da inversão positiva mostrou a reativação da falha principal, com a reativação de algumas falhas normais que delimitam a estrutura grabenforme. Empurrões e retroempurrões são desenvolvidos e se enraízam a partir da porção basal da falha lístrica, ou se desenvolveram na parte superior do pacote sedimentar, propagando-se em direção à base da estrutura grabenforme; ii) Série II: Analisou-se a geração de falhas associadas à formação de uma falha mestra planar, ortogonal à direção de tração/compressão. Nestes experimentos procurou-se também observar o papel da reologia na predisposição de falhas normais serem reativadas. Para esta série de experimentos, três tipos de experimentos foram realizados com sequências pré-tectônicas constituídas por diferentes tipos de material: apenas areia (série IIA); areia e gesso (série IIB); e areia e argila (série IIC). Nos experimentos da série II, a arquitetura estrutural final mostra que falhas normais foram completamente ou parcialmente reativadas, além do desenvolvimento de empurrões e retroempurrões que seccionam a porção basal da estrutura grabenforme. Os dados obtidos com o sistema PIV, mostraram que durante o v início da compressão, a deformação foi absorvida primeiramente pela compactação do material granular, e que após este processo, ocorre a reativação e criação de novas falhas, e que determinadas falhas alternam em intervalos ativos e inativos.Analog modeling has been used since the XIX century to simulate geological structures in order to understand the mechanisms that control their geometry and kinematics. The use of this tool in the oil industry, to help seismic interpretations (mainly searching for structural traps), helped to spread its use in the literature. Studies involving basin inversion are developed to improve understanding factors that influence the reactivation of pre-existing structures as well as their geometry. In this work, we analyze the construction of the structural architecture of a Fault system that underwent positive inversion, and analyzed the relationship between the generation of new Faults and reactivation of pre-existing normal Faults during a contraction event. In addition, the behavior and distribution of strain along the deformation process were performed based on images obtained and processed by Particle Image Velocimetry (PIV) system. Two series of experiments were developed: i) Series I: we analyzed the generation of Fault sets associated with a main Listric Fault and their reactivation during an inversion event. Two types of models were performed: one with Listric Fault, orthogonal to the direction of tension and compression (series IA), while in the other the lístrica Fault was oblique (obliquity = 80) (series IB). The final structural configuration after inversion showed major Fault and some of the normal Faults (delimiting the grabenform structure) reactivated. Thrust and backthrust were developed from the basal portion of Listric Fault, or in the upper part of the model, propagating towards the base of grabenform structure; ii) Series II: we analyzed the generation of Faults associated with the formation of a planar master Fault, orthogonal to the direction of both tension and compression. In these experiments, the role of rheology during normal Faults reactivation was analyzed. Three types of experiments were done varying the materials of the pre-tectonic sequences: sand only (series IIA); sand and gypsum ponder (series IIB); and sand and clay (series IIC). These experiments displayed the final architecture with normal Faults completely or partially reactivated, and the developed thrusts and backthrust sliced up the basal portion of the grabenform structure. PIV data showed that during the first stages of compression, deformation was absorbed mainly by rearrangement of the granular material (compactation) and only after this process Fault reactivation (or new Fault) occurs. During deformation, some Faults alternated intervals of activity and inactivity

  • Análise da reativação de falhas normais através da modelagem física com o uso do particle image velocimetry
    PROGRAMA DE PÓS-GRADUAÇÃO EM GEODINÂMICA E GEOFÍSICA, 2016
    Co-Authors: Luís Kennedy Andrade De ,sousa
    Abstract:

    Analog modeling has been used since the XIX century to simulate geological structures in order to understand the mechanisms that control their geometry and kinematics. The use of this tool in the oil industry, to help seismic interpretations (mainly searching for structural traps), helped to spread its use in the literature. Studies involving basin inversion are developed to improve understanding factors that influence the reactivation of pre-existing structures as well as their geometry. In this work, we analyze the construction of the structural architecture of a Fault system that underwent positive inversion, and analyzed the relationship between the generation of new Faults and reactivation of pre-existing normal Faults during a contraction event. In addition, the behavior and distribution of strain along the deformation process were performed based on images obtained and processed by Particle Image Velocimetry (PIV) system. Two series of experiments were developed: i) Series I: we analyzed the generation of Fault sets associated with a main Listric Fault and their reactivation during an inversion event. Two types of models were performed: one with Listric Fault, orthogonal to the direction of tension and compression (series IA), while in the other the lístrica Fault was oblique (obliquity = 80) (series IB). The final structural configuration after inversion showed major Fault and some of the normal Faults (delimiting the grabenform structure) reactivated. Thrust and backthrust were developed from the basal portion of Listric Fault, or in the upper part of the model, propagating towards the base of grabenform structure; ii) Series II: we analyzed the generation of Faults associated with the formation of a planar master Fault, orthogonal to the direction of both tension and compression. In these experiments, the role of rheology during normal Faults reactivation was analyzed. Three types of experiments were done varying the materials of the pre-tectonic sequences: sand only (series IIA); sand and gypsum ponder (series IIB); and sand and clay (series IIC). These experiments displayed the final architecture with normal Faults completely or partially reactivated, and the developed thrusts and backthrust sliced up the basal portion of the grabenform structure. PIV data showed that during the first stages of compression, deformation was absorbed mainly by rearrangement of the granular material (compactation) and only after this process Fault reactivation (or new Fault) occurs. During deformation, some Faults alternated intervals of activity and inactivity.Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)A modelagem analógica, desde o século XIX, vem sendo usada para simular estruturas geológicas com o objetivo de entender os mecanismos que controlam sua geometria e cinemática. O uso desta ferramenta na indústria do petróleo, para ajudar a interpretações sísmicas e, principalmente, para procurar armadilhas estruturais, contribuíram para difundir o uso desta ferramenta na literatura. Estudos envolvendo a modelagem analógica de inversão de bacias são desenvolvidos para melhorar o entendimento dos fatores que influenciam na reativação das estruturas pré-existentes, bem como sua geometria. Neste trabalho, procurou-se analisar a construção da arquitetura estrutural de um modelo de sistemas de falhas que sofre inversão positiva, e analisar a relação entre a geração de novas falhas e a reativação das falhas normais pré- existentes, durante um evento contracional. Adicionalmente, efetuou-se a análise do comportamento e distribuição do strain ao longo do processo deformacional a partir de imagens obtidas e processadas pelo sistema Particle Image Velocimetry (PIV). Foram estudados duas séries de experimentos: i) Série I: Analisou-se a geração de falhas associadas a geração de uma falha lístrica principal e sua reativação durante a inversão cinemática. Nesta série, dois tipos de modelos foram realizados: um com a falha lístrica, ortogonal a direção de tração e compressão (Série IA), e no outro a falha lístrica foi oblíqua (“α” = 80º) (Série IB). A configuração estrutural final da inversão positiva mostrou a reativação da falha principal, com a reativação de algumas falhas normais que delimitam a estrutura grabenforme. Empurrões e retroempurrões são desenvolvidos e se enraízam a partir da porção basal da falha lístrica, ou se desenvolveram na parte superior do pacote sedimentar, propagando-se em direção à base da estrutura grabenforme; ii) Série II: Analisou-se a geração de falhas associadas à formação de uma falha mestra planar, ortogonal à direção de tração/compressão. Nestes experimentos procurou-se também observar o papel da reologia na predisposição de falhas normais serem reativadas. Para esta série de experimentos, três tipos de experimentos foram realizados com sequências pré-tectônicas constituídas por diferentes tipos de material: apenas areia (série IIA); areia e gesso (série IIB); e areia e argila (série IIC). Nos experimentos da série II, a arquitetura estrutural final mostra que falhas normais foram completamente ou parcialmente reativadas, além do desenvolvimento de empurrões e retroempurrões que seccionam a porção basal da estrutura grabenforme. Os dados obtidos com o sistema PIV, mostraram que durante o v início da compressão, a deformação foi absorvida primeiramente pela compactação do material granular, e que após este processo, ocorre a reativação e criação de novas falhas, e que determinadas falhas alternam em intervalos ativos e inativos

Kei Ogata - One of the best experts on this subject based on the ideXlab platform.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.

  • architecture deformation style and petrophysical properties of growth Fault systems the late triassic deltaic succession of southern edgeoya east svalbard
    Basin Research, 2018
    Co-Authors: Kei Ogata, Mark Joseph Mulrooney, Alvar Braathen, Harmon D Maher, Per Terje Osmundsen, Ingrid Anell, Aleksandra Smyraksikora, Fabrizio Balsamo
    Abstract:

    The Late Triassic outcrops on southern Edgeoya, East Svalbard, allow a multiscale study of syn-sedimentary Listric growth Faults located in the prodelta region of a regional prograding system. At least three hierarchical orders of growth Faults have been recognized, each showing different deformation mechanisms, styles and stratigraphic locations of the associated detachment interval. The Faults, characterized by mutually influencing deformation envelopes over space-time, generally show SW- to SE-dipping directions, indicating a counter-regional trend with respect to the inferred W-NW directed progradation of the associated delta system. The down-dip movement is accommodated by polyphase deformation, with the different Fault architectural elements recording a time-dependent transition from fluidal-hydroplastic to ductile-brittle deformation, which is also conceptually scale-dependent, from the smaller- (3rd order) to the larger-scale (1st order) end-member Faults respectively. A shift from distributed strain to strain localization towards the Fault cores is observed at the meso to microscale (<1 mm), and in the variation in petrophysical parameters of the litho-structural facies across and along the Fault envelope, with bulk porosity, density, pore size and microcrack intensity varying accordingly to deformation and reworking intensity of inherited structural fabrics. The second- and third-order Listric Fault nucleation points appear to be located above blind Fault tip-related monoclines involving cemented organic shales. Close to planar, through-going, first-order Faults cut across this boundary, eventually connecting with other favourable lower-hierarchy Fault to create seismic-scale Fault zones similar to those imaged in the nearby offshore areas. The inferred large-scale driving mechanisms for the first-order Faults are related to the combined effect of tectonic reactivation of deeper Palaeozoic structures in a far field stress regime due to the Uralide orogeny, and differential compaction associated with increased sand sedimentary input in a fine-grained, water-saturated, low-accommodation, prodeltaic depositional environment. In synergy to this large-scale picture, small-scale causative factors favouring second- and third-order Faulting seem to be related to mechanical-rheological instabilities related to localized shallow diagenesis and liquidization fronts.