Thrust tectonics on Brøggerhalvøya and their relationship to the Tertiary West Spitsbergen Fold-and-Thrust Belt

2002 ◽  
Vol 139 (1) ◽  
pp. 47-72 ◽  
Author(s):  
K. SAALMANN ◽  
F. THIEDIG
Keyword(s):  
Middle Eocene ◽  
Kinematic Model ◽  
Thrust Belt ◽  
Fold Belt ◽  
Kinematic Evolution ◽  
Fold And Thrust Belt ◽  
Thrust Tectonics ◽  
Tectonic Transport ◽  
Thrust Sheets ◽  
West Spitsbergen

The Tertiary fold-and-thrust belt on Brøggerhalvøya is characterized by a NE-vergent pile of nine thrust sheets. The sole thrust of the pile is located in Precambrian phyllites and climbs up-section to the northeast. Four lower thrust sheets consisting predominantly of Upper Palaeozoic sediments are overlain by two thrust sheets in the central part of the stack which contain a kilometre-scale syncline and anticline. The fold is cut by juxtaposed thrusts giving rise to the formation of three structurally higher basement-dominated thrust sheets. A multiple-stage kinematic model is proposed including (1) in-sequence foreland-propagating formation of the lower thrust sheets in response to N–S subhorizontal bedding-parallel movements, (2) a change in tectonic transport to ENE and out-of-sequence thrusting and formation of the kilometre-scale fold-structure followed by (3) truncation of the kilometre-scale fold and stacking of the highest basement-dominated thrust sheets by hind-ward-propagating out-of-sequence thrusting. The strain of the thrust sheets is predominantly compressive with the exception of the structurally highest thrust sheets, reflecting a temporal change to a more transpressive regime. Thrusting was followed by (4) N–S extension and (5) W–E extension. Comparison of the structural geometry and kinematic evolution of Brøggerhalvøya with the data reported for the fold belt further south allows us to assume a coeval evolution with the fold belt. A latest Paleocene/Early Eocene age for the main phase of thrusting is suggested for the West Spitsbergen Fold-and-Thrust Belt; the main phases therefore pre-date the separation of Svalbard and Greenland due to right-lateral movements along the Hornsund Fault Zone. The fold belt's temporal evolution followed by the formation of the Forlandsundet Graben can be linked with the plate-kinematic framework in the span between latest Paleocene and Middle Eocene times.

scholarly journals Examining the tectono-stratigraphic architecture, structural geometry, and kinematic evolution of the Himalayan fold-thrust belt, Kumaun, northwest India

Lithosphere ◽  
2019 ◽  
Vol 11 (4) ◽  
pp. 414-435 ◽  
Author(s):  
Subhadip Mandal ◽  
Delores M. Robinson ◽  
Matthew J. Kohn ◽  
Subodha Khanal ◽  
Oindrila Das
Keyword(s):  
Cross Section ◽  
Structural Model ◽  
Kinematic Model ◽  
Thrust Belt ◽  
Main Central Thrust ◽  
Thrust Sheet ◽  
Balanced Cross Section ◽  
Kinematic Evolution ◽  
Thrust Sheets ◽  
Northwest India

Abstract Existing structural models of the Himalayan fold-thrust belt in Kumaun, northwest India, are based on a tectono-stratigraphy that assigns different stratigraphy to the Ramgarh, Berinag, Askot, and Munsiari thrusts and treats the thrusts as separate structures. We reassess the tectono-stratigraphy of Kumaun, based on new and existing U-Pb zircon ages and whole-rock Nd isotopic values, and present a new structural model and deformation history through kinematic analysis using a balanced cross section. This study reveals that the rocks that currently crop out as the Ramgarh, Berinag, Askot, and Munsiari thrust sheets were part of the same, once laterally continuous stratigraphic unit, consisting of Lesser Himalayan Paleoproterozoic granitoids (ca. 1850 Ma) and metasedimentary rocks. These Paleoproterozoic rocks were shortened and duplexed into the Ramgarh-Munsiari thrust sheet and other Paleoproterozoic thrust sheets during Himalayan orogenesis. Our structural model contains a hinterland-dipping duplex that accommodates ∼541–575 km or 79%–80% of minimum shortening between the Main Frontal thrust and South Tibetan Detachment system. By adding in minimum shortening from the Tethyan Himalaya, we estimate a total minimum shortening of ∼674–751 km in the Himalayan fold-thrust belt. The Ramgarh-Munsiari thrust sheet and the Lesser Himalayan duplex are breached by erosion, separating the Paleoproterozoic Lesser Himalayan rocks of the Ramgarh-Munsiari thrust into the isolated, synclinal Almora, Askot, and Chiplakot klippen, where folding of the Ramgarh-Munsiari thrust sheet by the Lesser Himalayan duplex controls preservation of these klippen. The Ramgarh-Munsiari thrust carries the Paleoproterozoic Lesser Himalayan rocks ∼120 km southward from the footwall of the Main Central thrust and exposed them in the hanging wall of the Main Boundary thrust. Our kinematic model demonstrates that propagation of the thrust belt occurred from north to south with minor out-of-sequence thrusting and is consistent with a critical taper model for growth of the Himalayan thrust belt, following emplacement of midcrustal Greater Himalayan rocks. Our revised stratigraphy-based balanced cross section contains ∼120–200 km greater shortening than previously estimated through the Greater, Lesser, and Subhimalayan rocks.

Structural evolution of a frontal ramp section of the West Spitsbergen, Tertiary fold and thrust belt, north of Isfjorden, Spitsbergen

1994 ◽  
Vol 131 (1) ◽  
pp. 67-80 ◽  
Author(s):  
Ole Petter Wennberg ◽  
Arild Andresen ◽  
Sigurd Hansen ◽  
Steffen G. Bergh
Keyword(s):  
Large Scale ◽  
Structural Evolution ◽  
The West ◽  
Kinematic Evolution ◽  
Thrust Front ◽  
Fold And Thrust Belt ◽  
Fault Bend ◽  
Thrust Sheets ◽  
Geometric Relationship ◽  
West Spitsbergen

AbstractThe geometry and kinematic evolution of a frontal ramp section associated with the Tertiary West Spitsbergen Orogenic Belt has been investigated in a small area (Lappdalen) north of Isfjorden. The previously recognized thrust front corresponds to a complex step or ramp in the position of the sole-thrust in the area. The sole-thrust is localized to the evaporites of the Permian Gipshuken Formation to the west of the footwall ramp, whereas to the east it continues as a bedding-parallel thrust in Triassic shales (Sassendalen Group). The area to the west of the footwall ramp is characterized by large scale thrusts and folds involving the Permian Gipshuken and Kapp Starostin formations and the lower part of the Triassic Sassendalen Group. East of the footwall ramp both Permian and Triassic strata are sub-horizontal and apparently undeformed. Three major thrust sheets are recognized. Based on the geometric relationship between folds and faults in the area, both fault-bend and fault-propogation mechanisms of folding are inferred. Restoration of the Kapp Starostin Formation to its pre-deformational state indicates a minimum of 35% shortening. Structural observations within the Sassendalen Group in the study area and on Dickson Land suggest that some of this shortening is transmitted eastwards along one or more bedding parallel thrusts in the Sassendalen Group.

scholarly journals U–Pb dating of middle Eocene–Pliocene multiple tectonic pulses in the Alpine foreland

Solid Earth ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 2539-2551
Author(s):  
Luca Smeraglia ◽  
Nathan Looser ◽  
Olivier Fabbri ◽  
Flavien Choulet ◽  
Marcel Guillong ◽  
...  
Keyword(s):  
Middle Eocene ◽  
Regional Scale ◽  
Earthquake Hazard ◽  
Late Eocene ◽  
Passive Margin ◽  
Tectonic Activity ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Earthquake Hazard Assessment ◽  
Alpine Foreland

Abstract. Foreland fold-and-thrust belts (FTBs) record long-lived tectono-sedimentary activity, from passive margin sedimentation, flexuring, and further evolution into wedge accretion ahead of an advancing orogen. Therefore, dating fault activity is fundamental for plate movement reconstruction, resource exploration, and earthquake hazard assessment. Here, we report U–Pb ages of syn-tectonic calcite mineralizations from four thrusts and three tear faults sampled at the regional scale across the Jura fold-and-thrust belt in the northwestern Alpine foreland (eastern France). Three regional tectonic phases are recognized in the middle Eocene–Pliocene interval: (1) pre-orogenic faulting at 48.4±1.5 and 44.7±2.6 Ma associated with the far-field effect of the Alpine or Pyrenean compression, (2) syn-orogenic thrusting at 11.4±1.1, 10.6±0.5, 9.7±1.4, 9.6±0.3, and 7.5±1.1 Ma associated with the formation of the Jura fold-and-thrust belt with possible in-sequence thrust propagation, and (3) syn-orogenic tear faulting at 10.5±0.4, 9.1±6.5, 5.7±4.7, and at 4.8±1.7 Ma including the reactivation of a pre-orogenic fault at 3.9±2.9 Ma. Previously unknown faulting events at 48.4±1.5 and 44.7±2.6 Ma predate the reported late Eocene age for tectonic activity onset in the Alpine foreland by ∼10 Myr. In addition, we date the previously inferred reactivation of pre-orogenic strike-slip faults as tear faults during Jura imbrication. The U–Pb ages document a minimal time frame for the evolution of the Jura FTB wedge by possible in-sequence thrust imbrication above the low-friction basal decollement consisting of evaporites.

Structure of the Gare Kakheti foothills using seismic reflection profiles: implications for kinematic evolution of the Georgian part of Kura foreland fold-and-thrust belt

2020 ◽  
Author(s):  
Alexander Razmadze
Keyword(s):  
Cross Sections ◽  
Seismic Reflection ◽  
Structural Evolution ◽  
Foreland Basin ◽  
Thrust Belt ◽  
Fault Propagation ◽  
Seismic Reflection Data ◽  
Growth Strata ◽  
Kinematic Evolution ◽  
Fold And Thrust Belt

<p>Gare Kakheti foothills are located between Lesser Caucasus and Kakheti Ridge and are mainly represented by the series of NEN dipping thrust faults, most of which are associated with fault‐related folds. Gare Kakheti foothills as a part of the Kura foreland fold-and-thrust belt developed formerly as a foreland basin (Oligocene-Lower Miocene) (e.g. Alania et al., 2017). Neogene shallow marine and continental sediments in the Gare Kakheti foothills keep the record on the stratigraphy and structural evolution of the study area during the compressive deformation. Interpreted seismic profiles and structural cross-sections across the Udabno, Tsitsmatiani, and Berebisseri synclines show that they are thrust-top basins. Seismic reflection data reveal the presence of growth fault-propagation folds and some structural wedges (or duplex). The evolution of the Udabno, Tsitsmatiani, and Berebisseri basins is compared with simple models of thrust-top basins whose development is controlled by the kinematics of competing for growth anticlines. Growth anticlines are mainly represented by fault-propagation folds. The geometry of growth strata in associated footwall synclines and the sedimentary infill of thrust-top basins provide information on the thrusting activity in terms of location, geometry, and age.<br>This work was supported by Shota Rustaveli National Science Foundation (SRNSF - #PHDF-19-268).</p><p> </p>

Post-depositional history of the Miocene Gorgoglione Formation (southern Apennines, Italy): inferences from mineralogical and structural analyses

2015 ◽  
Vol 186 (4-5) ◽  
pp. 243-256 ◽  
Author(s):  
Francesco Cavalcante ◽  
Giacomo Prosser ◽  
Fabrizio Agosta ◽  
Claudia Belviso ◽  
Giuseppe Corrado
Keyword(s):  
Structural Data ◽  
Axial Plane ◽  
Thrust Belt ◽  
Southern Apennines ◽  
High Potassium ◽  
Upper Miocene ◽  
Fold And Thrust Belt ◽  
Thrust Sheets ◽  
Layer Increase ◽  
Illitization Process

Abstract The Gorgoglione Formation represents the infill of a thrust-top basin, which records the tectonic evolution of the southern Apennines (Italy) since Upper Miocene times. The Upper Miocene basin was divided into two main sub-basins, showing both about NNW-SSW elongation. During ongoing contractional deformation, the Gorgoglione basin was incorporated into the allochthonous units of the Apennine fold-and-thrust belt, as outlined by the emplacement of thrust sheets of internal provenance (Sicilide Unit) and by the development of two main generations of tight to open folds. In this work, the modalities of deformation associated to the incorporation of the Gorgoglione Formation into the fold-and-thrust belt has been documented by means of mineralogical and structural analyses. Mineralogical data show that, in the northeastern sub-basin of the Gorgoglione Formation, the illite content and the order of illite/smectite mixed layer increase near the contact with the overlaying Sicilide Unit. These data are hence used to estimate the relative tectonic load produced by thrusting of the aforementioned tectonic unit. Structural data are consistent with tight, NNW-trending, meso-scale folds particularly frequent in the upper pelitic/arenaceous portion of the Gorgoglione Formation. Within these folded pelitic levels, a well-developed axial-plane foliation, and an ordered I/S (R1 and R3) with higher illite content, is documented. Instead, other folds developed far away from the Sicilide klippen show an incipient axial-plane foliation and a random I/S (R0) with lower illite amount is found in pelites. The data suggest that the eastern sub-basin of the Gorgoglione Formation underwent variable tectonic load, increasing from E to W, as well as deformation produced by thrusting of Sicilide sheet. The mineralogical data also indicate that illitization process is favoured for the high availability of potassium due to the dissolution of k-feldspar. High potassium availability affects the samples subjected to the highest diagenetic degree, characterized by kaolinite illitization process.

scholarly journals TECTÔNICA DA FAIXA DE DOBRAMENTOS BRASÍLIA – SETORES SETENTRIONAL E MERIDIONAL.

2012 ◽  
Author(s):  
Alexandre Uhlein ◽  
Marco Antônio Fonseca ◽  
Hildor José Seer ◽  
Marcel Auguste Dardenne
Keyword(s):  
Ductile Deformation ◽  
Low Grade ◽  
Thrust Belt ◽  
Fold Belt ◽  
Central Brazil ◽  
Structural Style ◽  
Deformational History ◽  
Fold And Thrust Belt ◽  
Lithostratigraphic Units ◽  
External Domain

A Faixa neoproterozóica de dobramentos e empurrões Brasília é uma das unidades tectônicas do Brasil Central. Uma análiseestrutural e tectônica da Faixa Brasília é aqui apresentada, com dois domínios estruturais: (1) interno, com unidades alóctones, foliação Spsubhorizontal ou suavemente dobrada e médio a alto grau de metamorfismo. (2) domínio externo, com estrutura de dobras e empurrões,predomínio de foliação Sp e médio a baixo grau de metamorfismo. A leste da Faixa Brasília ocorre o domínio cratônico (Craton do São Francisco), com unidades autóctones, suavemente dobradas. A vergência das dobras e empurrões é, geralmente, para o Cráton do SãoFrancisco. O encurtamento na cobertura é balanceado por zonas de cisalhamento, amplas dobras, falhas de empurrão e inversas e falhastranscorrentes. O estilo da deformação varia com o nível crustal. Assim, no domínio externo da faixa, predomina um estilo thin-skinned,enquanto que no domínio interno, aparecem zonas de deformação dúcteis mais intensas e largas, com metamorfismo mais alto (estilothick-skinned). O segmento sul da Faixa Brasília está mais deformado e provavelmente representa o resultado de uma colisão diacrônica,mais antiga, em relação ao setor setentrional. A mega inflexão dos Pirineus e a zona de superposição pode ser o resultado da interferênciaentre duas faixas neoproterozóicas distintas, com transporte tectônico local de Norte para o Sul.Palavras chave: Faixa móvel neoproterozóica Brasília; estilo nstrutural; evolução geodinâmica. ABSTRACTTECTONICS OF THE BRASÍLIA FOLD BELT: THE NORTHERN AND SOUTHERN PARTS - The Neoproterozoic (ca. 650-580) Ma Brasíliafold-and-thrust-belt is a major tectonic unit in Central Brazil and can be divided into two structural domains (internal and external). In theinternal domain, most surface rocks consist of allochthonous units in a higher metamorphic grade displaying low dipping cleavage,asymmetrical folds and thrusts with significant stratigraphic repetition. The external domain is a typical foreland fold-and-thrust belt wheremedium to low grade metamorphic rocks prevail and present steeply dipping cleavage Sp. Towards the cratonic area (cratonic domain),most lithostratigraphic units are authoctonous with vertical open folds and slaty cleavage. The general vergence of folds and thrust faults inboth domains is towards the east (São Francisco Craton). Shortening of cover across the fold belt is almost always balanced by coverbasementdetachments, fold-and-thrust structures and also by NE or NW trending wrench faults. The style of deformation variesconsiderably across strike due to crustal level. Typical thin-skinned fault-fold morphology in external domain gives rise downwards to morepervasive wide zones of ductile deformation at high metamorphic grades (thick-skinned structures) in the internal domain. The Southernpart of the Brasilia belt has a more complex deformational history than the northern one. This is probably due to structural overprintcaused by a diachronic collision. The Pirineus Inflection, where local vergence is towards the South, may represent the interference zonebetween the the two parts.Keywords: Neoproterozoic Brasília fold-and-thrust belt; structural style; Geodinamic evolution.

scholarly journals Thrust tectonics in the central part of the External Hellenides, the case of the Gavrovo thrust

2017 ◽  
Vol 47 (2) ◽  
pp. 540
Author(s):  
E. Kamberis ◽  
S. Sotiropoulos ◽  
F. Marnelis ◽  
N. Rigakis
Keyword(s):  
Structural Deformation ◽  
Thrust Belt ◽  
Seismic Profiles ◽  
The West ◽  
Thrust Faulting ◽  
Fold And Thrust Belt ◽  
Thrust Tectonics ◽  
Extensional Faulting ◽  
Surface Geology ◽  
Flat Geometry

Thrust faulting plays an important role in the structural deformation of Gavrovo and Ionian zones in the central part of the ‘External Hellenides’ fold-and-thrust belt. The Skolis mountain in NW Peloponnese as well as the Varassova and Klokova mountains in Etoloakarnania are representative cases of ramp anticlines associated with the Gavrovo thrust. Surface geology, stratigraphic data and interpretation of seismic profiles indicate that it is a crustal-scale thrust acted throughout the Oligocene time. It is characterized by a ramp-flat geometry and significant displacement (greater than 10 km). Out of sequence thrust segmentation is inferred in south Etoloakarnania area. Down flexure and extensional faulting in the Ionian zone facilitated the thrust propagation to the west. The thrust emplacement triggered halokenetic movement of the Triassic evaporites in the Ionian zone as well as diapirisms that were developed in a later stage in the vicinity of the Skolis mountain.

scholarly journals The Kala Chitta foreland fold and thrust belt, Northern Pakistan

1995 ◽  
Vol 10 ◽  
Author(s):  
M. Kaleem Akhtar Qureshi ◽  
Aftab Ahmad Butt ◽  
Riaz A. Sheikh
Keyword(s):  
Large Scale ◽  
Middle Eocene ◽  
Thrust Belt ◽  
Northern Pakistan ◽  
Structural Framework ◽  
Fold And Thrust Belt ◽  
Detachment Surface ◽  
Basal Detachment

The present structural framework of the Kala Chitta Range evolved through movement between two detachment surfaces. The Precambrian Attock Slates acted as a basal detachment surface above which large scale horizontal compression took place to produce the main structural framework of the Kala Chitta Range. The Middle Eocene argillaceous and gypsiferous Kuldana Formation behaved as the upper detachment surface giving rise to blind thrusts which were later exposed due to the intense erosion of the overlying folded Miocene strata.

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