scholarly journals Filling Materials in Brittle Structures as Indicator of Cenozoic Tectonic Events in Southeastern Brazil

2020 ◽  
Vol 43 (2) ◽  
Author(s):  
Salomão Silva Calegari ◽  
Thaís Ruy Aiolfi ◽  
Mirna Aparecida Neves ◽  
Caroline Cibele Vieira Soares ◽  
Rodson De Abreu Marques ◽  
...  
Keyword(s):  
Manganese Oxides ◽  
Southeastern Brazil ◽  
Normal Faults ◽  
Mineral Formation ◽  
Mineral Precipitation ◽  
Geological Structures ◽  
Weathering Processes ◽  
Mineralogical Association ◽  
Filling Materials ◽  
Tectonic Events

The filling materials in brittle structures can provide useful information about the Cenozoic evolution developed over proterozoic terrains. When these materials are affected by faults, they record deformation phases that can be determined chronologically and, in the occurrence of lateritic materials, it is possible to infer the paleoenvironmental conditions during the mineral formation. This work aimed to identify crystalline phases of brittle structure filling materials and to propose evolutionary interpretations for Cenozoic tectonic reactivation based on literature data. The study area is located in the Southern part of the Espírito Santo State, near the Brazilian Southeastern Continental Margin, where proterozoic geological structures have been reactivated since the mesozoic rift phase, up to the Holocene. The mineral assemblage found in the filling materials includes primary minerals such as quartz, muscovite, microcline, rutile, titanite, and bannisterite; and the weathering minerals such as kaolinite, illite, hematite, goethite, hydrobiotite, lithiophorite and, birnessite. The mineralogical association found in the filling materials denotes the action of fluid phases with mineral precipitation at the brittle discontinuities during the weathering processes that occurred during the Cenozoic, probably between the Miocene and the Pleistocene. The faults, which striations are marked on the filling materials, originated after (in the case of the manganese oxides) or during (in the case of the illite) the mineral formation, indicating that the maximum age of these faults is in the Miocene. The origin of the brittle structures that affected the filling materials studied here is linked to the uplifting of the Continental Brazilian Margin, when ancient geological structures were reactivated as normal faults due to the local action of an extensional regime.

scholarly journals Physical modelling of superimposed tectonic events in the Volta Redonda Basin, Southeastern Brazil

2020 ◽  
Vol 50 (3) ◽  
Author(s):  
Aurélio Kasakewitch Ribeiro ◽  
Marco Antonio Cetale Santos ◽  
Aline Theophilo Silva ◽  
Fernanda Silva Lourenço ◽  
Sílvia Cristina Barroso Negrão
Keyword(s):  
Physical Modelling ◽  
Southeastern Brazil ◽  
Tectonic Events

scholarly journals Extensional Messinian basins in the Central Mediterranean (Calabria, Italy): new stratigraphic and tectonic insights

2018 ◽  
Vol 73 ◽  
pp. 45 ◽  
Author(s):  
Alfonsa Milia ◽  
Maurizio M. Torrente
Keyword(s):  
Water Environment ◽  
Sedimentary Basins ◽  
Normal Faults ◽  
Seismic Profiles ◽  
Rift Basins ◽  
Central Mediterranean ◽  
Tectonic Events ◽  
Basin Subsidence ◽  
Basement Deformation ◽  
Two Stages

The direction of extension and the architecture of the Messinian basins of the Central Mediterranean region is a controversial issue. By combining original stratigraphic analysis of wells and seismic profiles collected offshore and onshore Calabria, we reassess the tectonic evolution that controlled the sedimentation and basement deformation during Messinian times. Three main deep sedimentary basins in the Calabria area record a Messinian succession formed by two clays/shales-dominated subunits subdivided by a halite-dominated subunit. The correlation with the worldwide recognized stratigraphic features permit to define the chronology of the stratigraphic and tectonic events. Three main rift basins that opened in a N-S direction have been recognized. On the contrary a fourth supradetachment basin opened toward the East. We found that the basin subsidence was controlled by two stages of activity of normal faults and that Messinian rift basins evolve in a deep-water environment. The overall pattern of extensional faults of the Central Mediterranean corresponds to normal faults striking parallel to the trench and normal faults striking at an oblique angle to the trench (Fig. 14). In particular in Campania and Calabria regions are present two rifts parallel to trench and an intervening rift orthogonal to the trench. We maintain that the recognized Messinian rift basins can be interpreted according to the “Double-door saloon tectonics”.

scholarly journals Influence of basement heterogeneity on the architecture of low subsidence rate Paleozoic intracratonic basins (Ahnet and Mouydir basins, Central Sahara)

2018 ◽  
Author(s):  
Paul Perron ◽  
Michel Guiraud ◽  
Emmanuelle Vennin ◽  
Isabelle Moretti ◽  
Éric Portier ◽  
...  
Keyword(s):  
Normal Faults ◽  
North African ◽  
Subsidence Rate ◽  
Tectonic Events ◽  
Structural Framework ◽  
Vertical Fault ◽  
Central Sahara ◽  
Local Inversion ◽  
Thickness Variations ◽  
Facies Succession

Abstract. The Paleozoic intracratonic North African Platform is characterized by an association of arches (ridges, domes, swells or paleo-highs) and low subsidence rate syncline basins of different wavelengths (75–620 km). The structural framework of the platform results from the accretion of Archean and Proterozoic terranes during the Pan-African orogeny (750–580 Ma). The Ahnet and Mouydir basins are successively delimited from east to west by the Amguid El Biod, Arak-Foum Belrem, and Azzel Matti arches, bounded by inherited Precambrian sub-vertical fault systems which were repeatedly reactivated or inverted during the Paleozoic. Major unconformities are related to several tectonic events such as the Cambrian–Ordovician extension, Ordovician–Silurian glacial rebound, Silurian–Devonian “Caledonian” extension/compression, late Devonian extension/compression, and “Hercynian” compression. The deposits associated with these arches and syncline basins exhibit thickness variations and facies changes ranging from continental to marine environments. The arches are characterized by thin amalgamated deposits with condensed and erosional surfaces, whereas the syncline basins exhibit thicker and well-preserved successions. In addition, the vertical facies succession evolves from thin Silurian to Givetian deposits into thick Upper Devonian sediments. Synsedimentary deformations are evidenced by wedges, truncations, and divergent onlaps. Locally, deformation is characterized by near-vertical planar normal faults responsible for horst and graben structuring associated with folding during the Cambrian–Ordovician–Silurian period. These structures may have been inverted or activated during the Devonian compression and the Carboniferous. The sedimentary infilling pattern and the nature of deformation result from the slow Paleozoic reactivation of Precambrian terranes bounded by vertical lithospheric fault zones. Alternating periods of tectonic quiescence and low-rate subsidence acceleration associated with extension and local inversion tectonics correspond to a succession of Paleozoic geodynamic events (i.e. far-field orogenic belt, glaciation).

scholarly journals From widespread Mississippian to localized Pennsylvanian extension in central Spitsbergen, Svalbard

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1535-1558
Author(s):  
Jean-Baptiste P. Koehl ◽  
Jhon M. Muñoz-Barrera
Keyword(s):  
Sedimentary Rocks ◽  
Fault Zones ◽  
Normal Faults ◽  
Late Devonian ◽  
Growth Strata ◽  
Tectonic Events ◽  
Basement Rocks ◽  
Field Evidence ◽  
History Of ◽  
Tectonic Settings

Abstract. In the Devonian–Carboniferous, a rapid succession of clustered extensional and contractional tectonic events is thought to have affected sedimentary rocks in central Spitsbergen, Svalbard. These events include Caledonian post-orogenic extensional collapse associated with the formation of thick Early–Middle Devonian basins, Late Devonian–Mississippian Ellesmerian contraction, and Early–Middle Pennsylvanian rifting, which resulted in the deposition of thick sedimentary units in Carboniferous basins like the Billefjorden Trough. The clustering of these varied tectonic settings sometimes makes it difficult to resolve the tectono-sedimentary history of individual stratigraphic units. Notably, the context of deposition of Mississippian clastic and coal-bearing sedimentary rocks of the Billefjorden Group is still debated, especially in central Spitsbergen. We present field evidence (e.g., growth strata and slickensides) from the northern part of the Billefjorden Trough, in Odellfjellet, suggesting that tilted Mississippian sedimentary strata of the Billefjorden Group deposited during active (Late/latest?) Mississippian extension. WNW–ESE-striking basin-oblique faults showing Mississippian growth strata systematically die out upwards within Mississippian to lowermost Pennsylvanian strata, thus suggesting a period of widespread WNW–ESE-directed extension in the Mississippian and an episode of localized extension in Early–Middle Pennsylvanian times. In addition, the presence of abundant basin-oblique faults in basement rocks adjacent to the Billefjorden Trough suggests that the formation of Mississippian normal faults was partly controlled by reactivation of preexisting Neoproterozoic (Timanian?) basement-seated fault zones. We propose that these preexisting faults reactivated as transverse or accommodation cross faults in or near the crest of transverse folds reflecting differential displacement along the Billefjorden Fault Zone. In Cenozoic times, a few margin-oblique faults (e.g., the Overgangshytta fault) may have mildly reactivated as oblique thrusts during transpression–contraction, but shallow-dipping, bedding-parallel, duplex-shaped décollements in shales of the Billefjorden Group possibly prevented substantial movement along these faults.

Late evolution of the inner Northern Apennines from the structure of the Monti del Chianti-Monte Cetona Ridge (Tuscany, Italy)

2021 ◽  
Author(s):  
Andrea Brogi
Keyword(s):  
Middle Miocene ◽  
Sedimentary Basins ◽  
Northern Apennines ◽  
Normal Faults ◽  
Tyrrhenian Sea ◽  
Scientific Debate ◽  
Marine Deposits ◽  
Accommodation Space ◽  
Tectonic Events ◽  
Late Evolution

<p>The Neogene and Quaternary tectonic evolution of the inner Northern Apennines (i.e southern Tuscany and northern Tyrrhenian Sea), as well as its crustal features (i.e. low crustal thickness, Neogene-Quaternary magmatism, widespread geothermal anomalies, lateral segmentation of the stacked tectonic units, extensive deep sedimentary basins), are framed in different geodynamic scenarios: compressional, extensional or both, pulsing. Consequently, the basin and range structure that characterises the northern Tyrrhenian Sea and southern Tuscany is considered as a consequence of (i) out-of-sequence thrusts and related thrust-top-basins, (ii) polyphased normal faulting that formed horst and graben structures or (iii) a combination of both. This paper provides a new dataset from a sector of the eastern inner Northern Apennines (i.e. Monti del Chianti - Monte Cetona ridge) contributing to this scientific debate. New fieldwork and structural analysis carried out in selected areas along the ridge allowed to define the chronology of the main tectonic events on the basis of their influence on the marine and continental sedimentation. The dataset supports for early Miocene - (?) Serravallian in-sequence and out-of-sequence thrusting. Thrusting produced complex staking patterns of Tuscan and Ligurian Units. Extensional detachments developed since later middle Miocene and controlled the Neogene sedimentation in bowl-shaped structural depressions, later dissected by normal faults enhancing the accommodation space for Pliocene marine deposits in broad NNW-trending basins (Siena-Radicofani and Valdichiana Basins). In this perspective, no data supports for active, continuous or pulsing, compressional tectonics after late Serravalian. As a result, in the whole inland inner Northern Apennines the extensional tectonics was continuously active at least since middle Miocene and controlled the basins development, magmatism and structure of the crust and lithosphere.</p>

scholarly journals POLA ANOMALI BOUGUER DAN ANOMALI MAGNET DAN KAITANNYA DENGAN PROSPEK SUMBER DAYA MINERAL DAN ENERGI DI PULAU LAUT, PULAU SEBUKU DAN SELAT SEBUKU, KALIMANTAN SELATAN

2016 ◽  
Vol 11 (3) ◽  
pp. 115
Author(s):  
Subagio Subagio ◽  
Tatang Patmawidjaya
Keyword(s):  
Sedimentary Basin ◽  
Bouguer Anomaly ◽  
Mineral Resources ◽  
Magnetic Anomalies ◽  
Normal Faults ◽  
Thrust Faults ◽  
Bouguer Anomalies ◽  
Circular Pattern ◽  
Tectonic Events ◽  
Range Of Values

Anomali Bouguer Pulau Laut, Pulau Sebuku, dan Selat Sebuku dapat dikelompokkan menjadi dua wilayah anomali meliputi anomali berpola melingkar dengan kisaran nilai dari 40 hingga 64 mGal, dan anomali berpola lurus dengan kisaran nilai 40 hingga 50 mGal. Anomali magnet di daerah ini bervariasi dari -700 hingga 1600 nT, membentuk pola tinggian dan rendahan. Anomali Bouguer berpola melingkar dengan kisaran nilai 45-64 mGal mencerminkan batuan ultrabasa yang relatif mendekati permukaan. Batuan ultrabasa yang tersingkap di permukaan dicirikan oleh anomali magnet tinggi. Anomali Bouguer berpola kontur lurus sejajar menunjukkan sesar naik maupun sesar turun yang terdapat di daerah tersebut. Sesar naik yang berkembang di daerah penelitian umumnya terdapat di Pegunungan Meratus yang mempunyai mendala geologi sama. Anomali Bouguer dan anomali magnet rendah mencerminkan cekungan sedimen. yang diakibatkan oleh adanya gaya tarikan yang pernah ada. Batuan terobosan yang dijumpai, diduga terbentuk bersamaan dengan periode gaya tarikan ini. Serangkaian proses tektonik yang hasilnya terekam pada anomali Bouguer, anomali magnet, dan singkapan batuan memberi implikasi kemungkinan terdapatnya sumber daya energi dan mineral di daerah penelitian. Mineralisasi logam diperkirakan dapat dijumpai di sekitar daerah terobosan. Bijih besi, nikel, dan kromit kemungkinan terdapat di daerah ultra-mafik, sedangkan batubara di daerah cekungan sedimen. Kata kunci : Anomali Bouguer, anomali magnet, sumber daya energi dan mineral, sesar naik dan sesar turun. Bouguer anomaly of the Laut Island, Sebuku Island, and The Sebuku Strait can be grouped into two anomaly groups covering the circular pattern anomaly with range from 40 to 64 mGals, and the straight pattern with range of values from 40 to 50 mGals. The range of magnetic anomalies in the study area area from -700 to 1600 nT, forming high and low anomay patterns. The circular pattern of the Bouguer anomalies with range from 45 to 64 mGals reflects that the ultramafic rocks relatively close to the surface, while exposed ultrabasic rocks are indicated by high magnetic anomalies. Paralled pattern contour of Bouguer anomaly show a thrust faults and normal faults in this area. Thrust faults of commonly develop in Meratus Mountaint that has the same geological setting. The low Bouguer and magnetic anomalies reflect a sedimentary basin caused by previous tensional force. The intrusion rocks found in the study area suggest to be formed together with this tensional force period. A series of tectonic events recorded in Bougue anomaly, magnetic anomaly, and out crops gave the implication the possibility the present of energy and mineral resources in the study area. Metal mineralization suggests to be found in the intrusion area. Irons, nickels and chromites supposed can be found in the ulta-mafic area, while coal can be found in the sedimentary basin. Keywords : Bouguer anomalies, magnetic anomalies, energy and mineral resources, thrust and normal faults.

scholarly journals Influence of basement heterogeneity on the architecture of low subsidence rate Paleozoic intracratonic basins (Reggane, Ahnet, Mouydir and Illizi basins, Hoggar Massif)

Solid Earth ◽  
2018 ◽  
Vol 9 (6) ◽  
pp. 1239-1275 ◽  
Author(s):  
Paul Perron ◽  
Michel Guiraud ◽  
Emmanuelle Vennin ◽  
Isabelle Moretti ◽  
Éric Portier ◽  
...  
Keyword(s):  
Shear Zones ◽  
Normal Faults ◽  
Late Devonian ◽  
North African ◽  
Subsidence Rate ◽  
Tectonic Events ◽  
Structural Framework ◽  
Local Inversion ◽  
Thickness Variations ◽  
Facies Succession

Abstract. The Paleozoic intracratonic North African Platform is characterized by an association of arches (ridges, domes, swells, or paleo-highs) and low subsidence rate syncline basins of different wavelengths (75–620 km). The Reggane, Ahnet, Mouydir and Illizi basins are successively delimited from east to west by the Amguid El Biod, Arak-Foum Belrem, and Azzel Matti arches. Through the analysis of new unpublished geological data (i.e., satellite images, well logs, seismic lines), the deposits associated with these arches and syncline basins exhibit thickness variations and facies changes ranging from continental to marine environments. The arches are characterized by thin amalgamated deposits with condensed and erosional surfaces, whereas the syncline basins exhibit thicker and well-preserved successions. In addition, the vertical facies succession evolves from thin Silurian to Givetian deposits into thick Upper Devonian sediments. Synsedimentary structures and major unconformities are related to several tectonic events such as the Cambrian–Ordovician extension, the Ordovician–Silurian glacial rebound, the Silurian–Devonian Caledonian extension/compression, the late Devonian extension/compression, and the Hercynian compression. Locally, deformation is characterized by near-vertical planar normal faults responsible for horst and graben structuring associated with folding during the Cambrian–Ordovician–Silurian period. These structures may have been inverted or reactivated during the Devonian (i.e., Caledonian, Mid–Late Devonian) compression and the Carboniferous (i.e., pre-Hercynian to Hercynian). Additionally, basement characterization from geological and geophysics data (aeromagnetic and gravity maps), shows an interesting age-dependent zonation of the terranes which are bounded by mega-shear zones within the arches–basins framework. The old terranes are situated under arches while the young terranes are located under the basins depocenter. This structural framework results from the accretion of Archean and Proterozoic terranes inherited from former orogeny (e.g., Pan-African orogeny 900–520 Ma). Therefore, the sedimentary infilling pattern and the nature of deformation result from the repeated slow Paleozoic reactivation of Precambrian terranes bounded by subvertical lithospheric fault systems. Alternating periods of tectonic quiescence and low-rate subsidence acceleration associated with extension and local inversion tectonics correspond to a succession of Paleozoic geodynamic events (i.e., far-field orogenic belt, glaciation).

Relief Inversion in the Avrona Playa as Evidence of Large-Magnitude Historical Earthquakes, Southern Arava Valley, Dead Sea Rift

1999 ◽  
Vol 52 (1) ◽  
pp. 76-91 ◽  
Author(s):  
Rivka Amit ◽  
Ezra Zilberman ◽  
Naomi Porat ◽  
Yehouda Enzel
Keyword(s):  
Historical Earthquakes ◽  
Dead Sea ◽  
Soil Development ◽  
Normal Faults ◽  
Seismic Gap ◽  
Large Magnitude ◽  
Tectonic Event ◽  
Dead Sea Transform ◽  
Tectonic Events ◽  
Arava Valley

The Arava Valley section of the Dead Sea Transform (DST) in southern Israel is characterized by the absence of seismic activity in recent times. However, paleoseismic analysis of sediments in the Avrona Playa, a pull-apart basin along the DST, reveals that at least six M > 6 tectonic events have affected the Avrona playa in the last 14,000 yr. The recurrence interval of the events is approximately 2000 yr. Trenched normal faults and push-up ridges in the playa show that the upper 2 m of the deformed sedimentary sequence consists of playa deposits with uniform soil development. The deformed sediments and the soil are typical of basins with an endoreic fluvial system. Based on the limiting age of the sequence and the extent of soil development, faulting in the playa, followed by compression and uplift, occurred in the last 1000 yr. This most recent tectonic event displaced the surface by at least 1 m, consistent with a M > 6.5 earthquake. This earthquake changed the morphology of the Avrona Playa from a closed system with internal drainage to an open basin, resulting in relief inversion. The seismic quiescence in the Arava may indicate a seismic gap in this segment of the DST.

scholarly journals STRATIGRAFI SEISMIK LAUT DANGKAL PERAIRAN CELUKANBWANG, BALI UTARA

2016 ◽  
Vol 1 (2) ◽  
Author(s):  
Nyoman Astawa ◽  
Wayan Lugra
Keyword(s):  
Volcanic Rocks ◽  
Seismic Survey ◽  
Normal Faults ◽  
Geological Condition ◽  
Geological Structures ◽  
Strong Energy ◽  
Energy Environment ◽  
Seismic Records ◽  
Break Area ◽  
Marine Seismic

Suvai seismik laut sepanjang pantai dan lepas pantai Celukanbawang Bali Utara dimaksudkan untuk mendapatkan data rekaman seismik guna menerangkan kondisi geologi daerah telitian. Berdasarkan pendekatan stratigrafi seismik, rekaman data seismik menunjukkan bahwa di daerah telitian terdapat 2 (dua) runtunan seismik, yaitu runtunan A dan B. Runtunan A diduga merupakan batuan volkanik sedangkan runtunan B diduga merupakan batuan sedimen yang diendapkan dalam lingkungan energi cukup kuat. Pada daerah slope break banyak dijumpai diapir, dan struktur geologi yang berkembang di daerah telitian adalah sesar normal. The marine seismic survey along the coast and offshore of Celukanbawang, North Bali, was directed to obtained seismic records to explain the geological condition of the study area. On the basis of seismic stratigraphy approach, the seismic records indicate that in the study area presence 2 (two) seismic sequences, those are sequence A and B. Sequence A is suggested as a volcanic rocks while sequence B is suggested as sedimentary rocks deposited within strong energy environment. At the slope break area the diapers were found, and the geological structures develope in the study area are normal faults.

Sign in / Sign up

Export Citation Format

Share Document