Analysis of structural trends of sub-sea-floor strata in the Isfjorden area of the West Spitsbergen Fold-and-Thrust Belt based on multichannel seismic data

2013 ◽  
Vol 170 (4) ◽  
pp. 657-668 ◽  
Author(s):  
Maria Blinova ◽  
Jan Inge Faleide ◽  
Roy H. Gabrielsen ◽  
Rolf Mjelde
Keyword(s):  
Seismic Data ◽  
Thrust Belt ◽  
The West ◽  
Sea Floor ◽  
Fold And Thrust Belt ◽  
West Spitsbergen ◽  
Multichannel Seismic Data

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

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

scholarly journals Combined Multiple Attenuation Methods and Geological Interpretation : Seram Sea Case Study 2D Marine Seismic Data

2019 ◽  
Vol 34 (1) ◽  
Author(s):  
Tumpal Bernhard Nainggolan ◽  
Said Muhammad Rasidin ◽  
Imam Setiadi
Keyword(s):  
Satisfactory Result ◽  
Radon Transform ◽  
Seismic Data ◽  
Thrust Belt ◽  
Geological Interpretation ◽  
Structural Style ◽  
Predictive Deconvolution ◽  
Fold And Thrust Belt ◽  
Short Period ◽  
Marine Seismic

Multiple often and always appear in marine seismic data due to very high acoustic impedance contrasts. These events have undergone more than one reflection. This causes the signal to arrive back at the receiver at an erroneous time, which, in turn, causes false results and can result in data misinterpretation. Several types of multiple suppression have been studied in literature. Methods that attenuate multiples can be classified into three broad categories: deconvolution methods; filtering methods and wavefield prediction subtraction methods. The study area is situated on Seram Sea in between 131°15’E – 132°45’E and 3°0’S – 4°0’S, Seram Trough which is located beneath Seram Sea at northern part of the Banda-Arc – Australian collision zone and currently the site of contraction between Bird’s Head and Seram. This research uses predictive deconvolution and FK-filter to attenuate short period multiple from their move out, then continued by SRME method to predict multiple that cannot be attenuated from previous method, then followed by Radon transform to attenuate multiple that still left and cannot be attenuated by SRME method. The result of each method then compared to each other to see how well multiple attenuated. Predictive deconvolution and F-K filter could not give satisfactory result especially complex area where multiple in dipping event is not periodic, SRME method successfully attenuate multiple especially in near offset multiple without need subsurface information, while SRME method fails to attenuate long offset multiple, combination of SRME method and Radon transform can give satisfactory result with careful selection of the Radon transform parameters because it can obscure some primary reflectors. Based on geological interpretation, Seram Trough is built by dominant structural style of deposited fold and thrust belt. The deposited fold and thrust belt has a complexly fault geometry from western zone until eastern of seismic line.

Comoros – New Evidence and Arguments for Continental Crust

2016 ◽  
Author(s):  
John Milsom ◽  
Phil Roach ◽  
Chris Toland ◽  
Don Riaroh ◽  
Chris Budden ◽  
...  
Keyword(s):  
Continental Crust ◽  
Fracture Zone ◽  
Seismic Data ◽  
Gravity Anomalies ◽  
Magnetic Anomalies ◽  
Magnetic Data ◽  
The West ◽  
Sea Floor ◽  
Inappropriate Use ◽  
Sea Floor Spreading

ABSTRACT As part of an ongoing exploration effort, approximately 4000 line-km of seismic data have recently been acquired and interpreted within the Comoros Exclusive Economic Zone (EEZ). Magnetic and gravity values were recorded along the seismic lines and have been integrated with pre-existing regional data. The combined data sets provide new constraints on the nature of the crust beneath the West Somali Basin (WSB), which was created when Africa broke away from Gondwanaland and began to move north. Despite the absence of clear sea-floor spreading magnetic anomalies or gravity anomalies defining a fracture zone pattern, the crust beneath the WSB has been generally assumed to be oceanic, based largely on regional reconstructions. However, inappropriate use of regional magnetic data has led to conclusions being drawn that are not supported by evidence. The identification of the exact location of the continent-ocean boundary (COB) is less simple than would at first sight appear and, in particular, recent studies have cast doubt on a direct correlation between the COB and the Davie Fracture Zone (DFZ). The new high-quality reflection seismic data have imaged fault patterns east of the DFZ more consistent with extended continental crust, and the accompanying gravity and magnetic surveys have shown that the crust in this area is considerably thicker than normal oceanic and that linear magnetic anomalies typical of sea-floor spreading are absent. Rifting in the basin was probably initiated in Karoo times but the generation of new oceanic crust may have been delayed until about 154 Ma, when there was a switch in extension direction from NW-SE to N-S. From then until about 120 Ma relative movement between Africa and Madagascar was accommodated by extension in the West Somali and Mozambique basins and transform motion along the DFZ that linked them. A new understanding of the WSB can be achieved by taking note of newly-emerging concepts and new data from adjacent areas. The better-studied Mozambique Basin, where comprehensive recent surveys have revealed an unexpectedly complex spreading history, may provide important analogues for some stages in WSB evolution. At the same time the importance of wide continent-ocean transition zones marked by the presence of hyper-extended continental crust has become widely recognised. We make use of these new insights in explaining the anomalous results from the southern WSB and in assessing the prospectivity of the Comoros EEZ.

Controls on the evolution of passive-margin salt basins: Structure and evolution of the Salina del Bravo region, northeastern Mexico

2019 ◽  
Vol 132 (5-6) ◽  
pp. 997-1012 ◽  
Author(s):  
Michael R. Hudec ◽  
Tim P. Dooley ◽  
Frank J. Peel ◽  
Juan I. Soto
Keyword(s):  
Seismic Data ◽  
Passive Margin ◽  
Salt Tectonics ◽  
Structural Systems ◽  
Thrust Belt ◽  
Entire Region ◽  
Fold And Thrust Belt ◽  
Gravity Driven ◽  
Northeastern Mexico ◽  
Uplift History

Abstract Passive-margin salt basins tend to be much more deformed than their nonsalt equivalents, but they are by no means all the same. We used seismic data to study the Salina del Bravo region, northeast Mexico, to investigate the ways in which margin configuration and postsalt uplift history can influence passive-margin salt tectonics. The Salina del Bravo area contains four main structural systems, all of which trend NNE across the entire region. These structures are the Bravo trough, Sigsbee salt canopy, Perdido fold-and-thrust belt, and BAHA high. Gravity-driven deformation did not begin until more than 130 m.y. after salt deposition, because of buttressing against the BAHA high. We suggest that deformation was ultimately triggered in the Cenozoic by Cordilleran uplift that tilted the margin seaward and created a major sediment source terrane. Sediments shed from the uplift expelled salt seaward to form the Sigsbee canopy. At the same time, tilted and loaded sediments were translated seaward on the Louann salt until they were buttressed against the BAHA high, forming the Perdido fold-and-thrust belt. A physical model was built to test this hypothesis. The model was able to reproduce most of the major structures in the region, suggesting that the hypothesis is reasonable. The Salina del Bravo region shows how a downdip buttress can inhibit gravity-driven salt deformation in passive-margin salt basins. Furthermore, the area also shows the importance of postsalt uplift, which can destabilize a margin through a combination of tilting and sedimentation.

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

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