Rock magnetism and magnetic fabric of the Triassic rocks from the West Spitsbergen Fold-and-Thrust Belt and its foreland

2018 ◽  
Vol 728-729 ◽  
pp. 104-118 ◽  
Author(s):  
Katarzyna Dudzisz ◽  
Rafał Szaniawski ◽  
Krzysztof Michalski ◽  
Martin Chadima
Keyword(s):  
Rock Magnetism ◽  
Magnetic Fabric ◽  
Thrust Belt ◽  
The West ◽  
Fold And Thrust Belt ◽  
West Spitsbergen

Palaeomagnetic, rock-magnetic and mineralogical investigations of the Lower Triassic Vardebukta Formation from the southern part of the West Spitsbergen Fold and Thrust Belt

2018 ◽  
Vol 156 (4) ◽  
pp. 620-638 ◽  
Author(s):  
KATARZYNA DUDZISZ ◽  
KRZYSZTOF MICHALSKI ◽  
RAFAŁ SZANIAWSKI ◽  
KRZYSZTOF NEJBERT ◽  
GEOFFREY MANBY
Keyword(s):  
Remanent Magnetization ◽  
Vitrinite Reflectance ◽  
Lower Triassic ◽  
Natural Remanent Magnetization ◽  
The Other ◽  
Thrust Belt ◽  
The West ◽  
Fold And Thrust Belt ◽  
Oriented Samples ◽  
West Spitsbergen

AbstractMagnetic, petrological and mineralogical data from 13 sites (99 independently oriented samples) of the Lower Triassic rocks located in the SW segment of the West Spitsbergen Fold and Thrust Belt (WSFTB) are presented in order to identify the ferrimagnetic carriers and establish the origin of the natural remanent magnetization (NRM). Volcanic lithoclasts and other detrital resistive grains in which the primary magnetization might endure are present in some samples. On the other hand, petrological studies indicate that sulphide remineralization could have had an important influence on the remagnetization of these rocks. The dominant ferrimagnetic carriers are titanomagnetite and magnetite. While the titanomagnetite may preserve the primary magnetization, the magnetite is a more likely potential carrier of secondary overprints. The complex NRM patterns found in most of the samples may be explained by the coexistence and partial overlapping of components representing different stages of magnetization. Components of both polarities were identified in the investigated material. The reversal test performed on the most stable components that demagnetized above 300°C proved to be negative at the 95% confidence level at any stage of unfolding. They are better grouped, however, after 100% tectonic corrections and the most stable components are clustered in high inclinations (c. 70–80°). This suggests that at least part of the measured palaeomagnetic vectors represent a secondary prefolding magnetic overprint that originated in post-Jurassic time before the WSFTB event. Vitrinite reflectance studies show these rocks have not been subjected to any strong heating (<200°C).

scholarly journals A transpressional origin for the West Spitsbergen fold-and-thrust belt: Insight from analog modeling

Tectonics ◽  
2011 ◽  
Vol 30 (2) ◽  
pp. n/a-n/a ◽  
Author(s):  
Karen A. Leever ◽  
Roy H. Gabrielsen ◽  
Jan Inge Faleide ◽  
Alvar Braathen
Keyword(s):  
Thrust Belt ◽  
The West ◽  
Fold And Thrust Belt ◽  
Analog Modeling ◽  
West Spitsbergen

Chapter 9 Central western Spitsbergen

1997 ◽  
Vol 17 (1) ◽  
pp. 154-178
Author(s):  
W. Brian Harland
Keyword(s):  
Early Carboniferous ◽  
Whole Body ◽  
The West ◽  
Fold And Thrust Belt ◽  
Deformation Event ◽  
Slip Displacement ◽  
Western Side ◽  
West Spitsbergen ◽  
North And South ◽  
Main Deformation

The West Spitsbergen Orogen extends along the western side of Spitsbergen from Kongsfjorden to Sørkapp. It is the product of the latest main deformation event in Svalbard (Spitsbergian) dated provisionally as Eocene. The deformation is of a compressive or transpressive nature associated with the dextral strike-slip displacement between Svalbard and Greenland through Cenozoic time.Within this fold and thrust belt earlier diastrophism is evident: Minor Late Cretaceous tilting with uplift took place. The main events were mid-Paleozoic. The mid-Paleozoic tectogenesis is commonly referred to as Caledonian. However the age of deformation appears to be mid-Ordovician rather than the typical mid-Silurian of the central and eastern terranes of Svalbard. To avoid confusion this is referred to as the Eidembreen tectogenesis (analogous with the M'Clintock Orogeny of northern Ellesmere Island). Some uncertainty must remain as to whether there was any Silurian diastrophism or more likely, late Devonian Early Carboniferous tectonism to match the Ellesmerian events of Arctic Canada. The rocks divide naturally into younger (Carboniferous through Eocene) strata, i.e. post-Devonian, and pre-Devonian older rocks, there being no Devonian exposure within the orogen.Whereas the West Spitsbergen Orogeny was Paleogene (treated in Chapter 20) the orogen comprises the whole body of rock whether formed earlier or later. Because of the complex earlier history and variety of strata and structure along its length it is convenient to treat the structure in two parts, north and south of Isfjorden (Chapters 9 and 10 respectively). In this chapter the area treated comprises Oscar II Land and

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.

The Amer Belt: remnant of an Aphebian foreland fold and thrust belt

1986 ◽  
Vol 23 (12) ◽  
pp. 2012-2023 ◽  
Author(s):  
Judith G. Patterson
Keyword(s):  
Normal Faults ◽  
Lake Area ◽  
Thrust Belt ◽  
East Side ◽  
Progressive Deformation ◽  
The West ◽  
Polyphase Deformation ◽  
Thrust Belts ◽  
Fold And Thrust Belt ◽  
Stratigraphic Model

Aphebian supracrustal sequences occur as outliers throughout the northwestern portion of the Churchill Structural Province of the Canadian Shield. In the Amer Lake area, medium- to high-grade, polydeformed Archean rocks are unconformably overlain by the Amer supracrustal sequence, which comprises quartzite, carbonate, mafic volcanic, and meta-arkose and meta-pelitic units. This supracrustal sequence is interpreted as having been deposited under miogeoclinal conditions, transitional to exogeoclinal.The Amer sequence crops out in a broad, west-southwest-plunging synclinorium and contains evidence of polyphase deformation that includes the following: (1) Folds plunging gently to the west-southwest and west-southwest-striking thrust faults, transected by oblique tear faults. Thrust vergence is northerly to northwesterly, onto the Archean craton. Because of the orientation of the synclinorium, there is a down plunge view of the thrusts at the eastern end of the belt. (2) Younger, localized cross folds, probably representative of progressive deformation. (3) Late, northwest-trending normal faults, with east side down.The stratigraphic elements and family of structures in the Amer Belt are similar to those found in the foreland fold and thrust belts of major Phanerozoic and Proterozoic orogens. The Amer Belt is interpreted as being a remnant of a once extensive foreland fold and thrust belt.Some workers have considered the northwestern Churchill Structural Province a large cratonic foreland of the Trans-Hudson Orogen. However, remnants of a foreland fold and thrust belt, a major batholithic complex, and profound geophysical breaks interpreted as being possible sutures are incorporated into a new tectono-stratigraphic model that proposes that a cryptic Aphebian orogen exists in the northwestern Churchill Structural Province.

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.

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