scholarly journals Reply to Comments on “the Cenozoic Fold-and-Thrust Belt of Eastern Sardinia: Evidences from the Integration of Field Data With Numerically Balanced Geological Cross Section” by Arragoni et al. (2016)

Tectonics ◽  
2017 ◽  
Vol 36 (10) ◽  
pp. 2273-2278
Author(s):  
F. Salvini ◽  
S. Arragoni ◽  
P. Cianfarra ◽  
M. Maggi
Keyword(s):  
Cross Section ◽  
Field Data ◽  
Thrust Belt ◽  
Fold And Thrust Belt ◽  
Geological Cross Section

Improving 2D seismic interpretation in challenging settings by integration of restoration techniques: A case study from the Jura fold-and-thrust belt (Switzerland)

2015 ◽  
Vol 3 (4) ◽  
pp. SAA37-SAA58 ◽  
Author(s):  
Alexander Malz ◽  
Herfried Madritsch ◽  
Jonas Kley
Keyword(s):  
Cross Section ◽  
Lower Triassic ◽  
Seismic Profile ◽  
Seismic Interpretation ◽  
Mountain Range ◽  
Thrust Belt ◽  
Jura Mountains ◽  
Northern Switzerland ◽  
Fold And Thrust Belt

The structural geologic interpretation of reflection seismic data is affected by conceptual uncertainty, particularly in challenging onshore settings. This uncertainty can be significantly reduced by the integration of cross-section restoration and balancing techniques into the seismic interpretation workflow. Moreover, these techniques define a solid and comprehensive basis, grounding the interpretation and allowing a closer investigation of the deformation history that led to the interpreted structures. These benefits are demonstrated on the basis of a case study from the eastern Jura Mountains in northern Switzerland. This mountain range was formed by a thin-skinned foreland fold-and-thrust belt with a multiphase prethrusting tectonic history. Despite significant seismic acquisition and processing efforts, seismic imaging of the strongly deformed parts of the belt widely remains ambiguous. We have developed a detailed systematic interpretation workflow that is exemplified here for a single seismic profile across the Jura Main Thrust. Classical cross-section balancing techniques of equal bed lengths and areas were applied to validate and reinterpret the given seismic interpretation. Our results suggest that most of the observed structures resulted from thin-skinned deformation along a basal décollement in Lower Triassic evaporites, which is generally inferred for the Jura Mountains. Nevertheless, secondary detachment levels in above lying strata have to be considered as well. The stepwise restoration of the analyzed cross section points toward different styles of thin-skinned deformation and possibly several episodes of earlier basement-rooted faulting events, which are indicated by subtle stratigraphic thickness changes. In summary, our workflow allowed us to significantly improve the original seismic interpretation, highlight specific deformation styles, and illuminate possible prethrusting deformation events that would otherwise be easily overlooked.

Integrated multidisciplinary approach to constrain range fronts structure, a case study of the northern Tianshan piedmont (NW China)

2014 ◽  
Vol 185 (6) ◽  
pp. 379-392 ◽  
Author(s):  
Ke Chen ◽  
Charles Gumiaux ◽  
Romain Augier ◽  
Guillaume Martelet ◽  
Yan Chen ◽  
...  
Keyword(s):  
Data Analysis ◽  
Cross Section ◽  
Multidisciplinary Approach ◽  
Deep Structure ◽  
Thrust Belt ◽  
Seismic Profiles ◽  
Reflection Seismic ◽  
Fold And Thrust Belt ◽  
Northern Tianshan

Abstract Mountain fronts are key areas where to study the deformation mechanisms and the geodynamic evolution of orogenic belts. Different approaches based on either geological or geophysical data analysis have been proposed. However, in spite of recent theoretical and technical developments, these often remain within a single disciplinary framework and diverging views and models sometimes arise. The front of the northern Tianshan intracontinental collision range is thus quite exemplary for the variety of the tectonic models that have been proposed to explain its development. This paper introduces a multidisciplinary approach combining field geological/structural observations, reflection seismic profile interpretation, borehole results and a gravity study performed in the study area. This approach was conducted in the case study of a representative cross-section within the North Tianshan area, along the Jingou river. An extensive geological/structural survey across the fold and thrust belt was first carried out providing surface constraints on the shallowest parts of the section. Deep structure within the Junggar basin was constrained through processing and interpretation of reflection seismic data together with available borehole results. As it is often the case, the available seismic profiles do not extend to the frontal basement contact zone, or quality of the data was not good enough to allow interpretation. Consequently, a gravity survey and modelling finally allowed interpreting the deep structure of the cover/basement contact. By integrating all the data, the resulting regional-scale cross-section shows a new comprehensive image of the upper crustal structure in this area. In particular, results imply that the mountain basement thrust northwards onto the sedimentary layers with development of a second order fold. Besides, this study further suggests thick-skinned type deformations below the fold and thrust belt. From the example of the Jingou river section, this study illustrates the interest of incorporating gravity data analysis together with – more classical – seismic profiles interpretation and structural analyses for studying orogenic belt frontal areas.

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