scholarly journals Possible Quaternary growth of a hidden anticline at the front of the Jura fold-and-thrust belt: geomorphological constraints from the Forêt de Chaux area, France

2011 ◽  
Vol 182 (4) ◽  
pp. 337-346 ◽  
Author(s):  
Stéphane Molliex ◽  
Olivier Fabbri ◽  
Vincent Bichet ◽  
Herfried Madritsch
Keyword(s):  
Focal Depth ◽  
Fault Reactivation ◽  
Thrust Belt ◽  
Alluvial Deposits ◽  
The North ◽  
Basement Faults ◽  
Fold And Thrust Belt ◽  
Median Position ◽  
Differential Uplift ◽  
River Migration

Abstract This study presents new constraints for Plio-Quaternary (post-2.4 Ma to present-day) anticline growth along the frontal zone of the Jura fold-and-thrust belt, in the Forêt de Chaux area, located 30 km SW of Besançon. The Forêt de Chaux area consists of a N080°E-elongated depression bordered by the Doubs and Loue rivers to the north and south respectively, and filled with Sundgau-type Pliocene alluvial deposits. The upper surface of the Pliocene deposits between the Loue and Doubs rivers is marked by a N065°E-trending ridge crossing the depression in a median position. A differential uplift along this ridge, post-dating the deposition of the gravels (2.4 Ma), is suggested by several geomorphological observations such as the opposite river migration on each side of the ridge as well as variations of drainage geometry and incision intensity. Geological and geophysical subsurface data indicate that the ridge roughly coincides with the axis of an anticline hidden beneath the Pliocene deposits. The observed uplift is presumably related to a post-2.4 Ma anticline growth. The fact that the azimuth of the hidden anticline axis is parallel to the strike of deep-seated Late Paleozoic basement faults and not to the local strike of the thin-skinned Jura structures indicates that the inferred post-Pliocene deformation could possibly be an expression of a recent thick-skinned deformation of the basement of the northern Alpine foreland. The focal depth (15 km) of the February 24th, 2004, Besançon earthquake supports the hypothesis of a basement fault reactivation.

The Franklinian Composite Tectono-Sedimentary Element, North Greenland

2021 ◽  
pp. M57-2020-6
Author(s):  
John R. Hopper ◽  
Jon R. Ineson
Keyword(s):  
Heat Flow ◽  
Passive Margin ◽  
Thrust Belt ◽  
Reservoir Properties ◽  
Good Source ◽  
Petroleum Potential ◽  
The North ◽  
Fold And Thrust Belt ◽  
North Greenland ◽  
Mixed Carbonate

AbstractThe Franklinian margin composite tectono-sedimentary element (CTSE) in North Greenland is dominated by Neoproterozoic - lowermost Devonian sedimentary strata that include early syn-rift through passive margin TSEs of mixed carbonate and siliciclastic facies. The sedimentary successions are well exposed in much of northern Greenland, but locally were strongly affected by the Ellesmerian Orogeny, resulting in a fold and thrust belt that deformed the northernmost exposures. An exposed palaeo-oilfield attests to the petroleum potential of the basin. Several formations have good source potential and several others have good reservoir properties. Palaeo-heat flow indicators show that temperatures increase to the north, where much of the basin is over-mature. Because of the remoteness of the area and the restricted locations where petroleum potential is likely to remain, the basin is not currently a target for exploration.

scholarly journals The Saint-Ursanne earthquakes of 2000 revisited: evidence for active shallow thrust-faulting in the Jura fold-and-thrust belt

2022 ◽  
Vol 115 (1) ◽  
Author(s):  
Federica Lanza ◽  
Tobias Diehl ◽  
Nicholas Deichmann ◽  
Toni Kraft ◽  
Christophe Nussbaum ◽  
...  
Keyword(s):  
Template Matching ◽  
Sedimentary Cover ◽  
Mechanism Analysis ◽  
Thrust Belt ◽  
Northern Switzerland ◽  
Thrust Faulting ◽  
The North ◽  
Fold And Thrust Belt ◽  
New Findings ◽  
Mont Terri

AbstractThe interpretation of seismotectonic processes within the uppermost few kilometers of the Earth’s crust has proven challenging due to the often significant uncertainties in hypocenter locations and focal mechanisms of shallow seismicity. Here, we revisit the shallow seismic sequence of Saint-Ursanne of March and April 2000 and apply advanced seismological analyses to reduce these uncertainties. The sequence, consisting of five earthquakes of which the largest one reached a local magnitude (ML) of 3.2, occurred in the vicinity of two critical sites, the Mont Terri rock laboratory and Haute-Sorne, which is currently evaluated as a possible site for the development of a deep geothermal project. Template matching analysis for the period 2000–2021, including data from mini arrays installed in the region since 2014, suggests that the source of the 2000 sequence has not been persistently active ever since. Forward modelling of synthetic waveforms points to a very shallow source, between 0 and 1 km depth, and the focal mechanism analysis indicates a low-angle, NNW-dipping, thrust mechanism. These results combined with geological data suggest that the sequence is likely related to a backthrust fault located within the sedimentary cover and shed new light on the hosting lithology and source kinematics of the Saint-Ursanne sequence. Together with two other more recent shallow thrust faulting earthquakes near Grenchen and Neuchâtel in the north-central portion of the Jura fold-and-thrust belt (FTB), these new findings provide new insights into the present-day seismotectonic processes of the Jura FTB of northern Switzerland and suggest that the Jura FTB is still undergoing seismically active contraction at rates likely < 0.5 mm/yr. The shallow focal depths provide indications that this low-rate contraction in the NE portion of the Jura FTB is at least partly accommodated within the sedimentary cover and possibly decoupled from the basement.

The 2020 Mw 6.0 Jiashi Earthquake: Coinvolvement of Thin-Skinned Thrusting and Basement Shortening in Shaping the Keping-Tage Fold-and-Thrust Belt in Southwestern Tian Shan

2021 ◽  
Author(s):  
Yuqing He ◽  
Teng Wang ◽  
Lihua Fang ◽  
Li Zhao
Keyword(s):  
Surface Deformation ◽  
Reverse Fault ◽  
Thrust Belt ◽  
Coulomb Stress Changes ◽  
The North ◽  
Fold And Thrust Belt ◽  
Stress Changes ◽  
Mountain Front ◽  
Tear Fault ◽  
Tian Shan

Abstract The Keping-tage fold-and-thrust belt in southwest Tian Shan is seismically active, yet the most well-recorded earthquakes occurred south of the mountain front. The lack of large earthquakes beneath the fold-and-thrust belt thus hinders our understanding of the orogenic process to the north. The 2020 Mw 6.0 Jiashi earthquake is an important event with surface deformation in the fold-and-thrust belt well illuminated by Interferometric Synthetic Aperture Radar, providing an opportunity to study the present-day kinematics of the thrust front through the analysis of satellite measurements of surface deformations. Here, we employ the surface deformation and relocated aftershocks to investigate the fault-slip distribution associated to this event. Further added by an analysis of Coulomb stress changes, we derive a fault model involving slips on a shallow, low-angle (∼10°) north-dipping thrust fault as well as on a left-lateral tear fault and a high-angle south-dipping reverse fault in mid-crust. Aftershocks at depth reflect the basement-involved shortening activated by a thin-skinned thrust faulting event. In addition, this earthquake uplifted the southernmost mountain front with relatively low topography, indicating the basin-ward propagation of the southwest Tian Shan.

scholarly journals The role of basement-involved normal faults in the recent tectonics of western Taiwan

2016 ◽  
Vol 153 (5-6) ◽  
pp. 1166-1191 ◽  
Author(s):  
KENN-MING YANG ◽  
RUEY-JUIN RAU ◽  
HAO-YUN CHANG ◽  
CHING-YUN HSIEH ◽  
HSIN-HSIU TING ◽  
...  
Keyword(s):  
Active Faults ◽  
Foreland Basin ◽  
Normal Fault ◽  
Strike Slip ◽  
Fault Reactivation ◽  
Normal Faults ◽  
Thrust Belt ◽  
Structural Style ◽  
Fold And Thrust Belt ◽  
Recent Tectonics

AbstractIn the foreland area of western Taiwan, some of the pre-orogenic basement-involved normal faults were reactivated during the subsequent compressional tectonics. The main purpose of this paper is to investigate the role played by the pre-existing normal faults in the recent tectonics of western Taiwan. In NW Taiwan, reactivated normal faults with a strike-slip component have developed by linkage of reactivated single pre-existing normal faults in the foreland basin and acted as transverse structures for low-angle thrusts in the outer fold-and-thrust belt. In the later stage of their development, the transverse structures were thrusted and appear underneath the low-angle thrusts or became tear faults in the inner fold-and-thrust belt. In SW Taiwan, where the foreland basin is lacking normal fault reactivation, the pre-existing normal faults passively acted as ramp for the low-angle thrusts in the inner fold-and-thrust belt. Some of the active faults in western Taiwan may also be related to reactivated normal faults with right-lateral slip component. Some main earthquake shocks related to either strike-slip or thrust fault plane solution occurred on reactivated normal faults, implying a relationship between the pre-existing normal fault and the triggering of the recent major earthquakes. Along-strike contrast in structural style of normal fault reactivation gives rise to different characteristics of the deformation front for different parts of the foreland area in western Taiwan. Variations in the degree of normal fault reactivation also provide some insights into the way the crust embedding the pre-existing normal faults deformed in response to orogenic contraction.

scholarly journals The Mineralization and Structural Geology of the Porphyry Copper Deposits of Pakistan

2021 ◽  
Vol 19 (2) ◽  
pp. 130-136
Author(s):  
Syed Tallataf Hussain Shah ◽  
Nangyal Ghani Khan ◽  
Muhammad Imran Hafeez Abbasi ◽  
Kamran Tabassum ◽  
Syed Khaizer Wahab Shah
Keyword(s):  
Porphyry Copper ◽  
Island Arc ◽  
Fault System ◽  
Thrust Belt ◽  
Porphyry Copper Deposits ◽  
Copper Deposits ◽  
Magmatic Arc ◽  
The North ◽  
Fold And Thrust Belt ◽  
Late Tertiary

The purpose of this review is to shed light on copper deposits found in different regions of Pakistan. The geological attributes of copper deposits have been considered with their tectonic context. The porphyry copper deposits can be traced in Pakistan from the north through Kohistan Island Arc (KIA) up to the south to Chaghi Magmatic Arc (CMA). These deposits are mainly found in and around the Late Tertiary–Early Tertiary Himalayan Belt, Kohistan magmatic arc, Karakorum Block Foreland fold and thrust belt, Ophiolite Thrust belt, Suture zone and Chaghi Magmatic Arc. These deposits in Pakistan are chiefly established in different episodes of tectonic regimes, including subduction processes, oceanic island arc, continental arc, along with Chaman- OrnachNal Fault system and post-collisional settings.

The pre-Mesozoic basement underneath the Jura Mountains fold-and-thrust belt: an overview from models and maps

2020 ◽  
Author(s):  
Marc Schori ◽  
Anna Sommaruga ◽  
Jon Mosar
Keyword(s):  
Cross Sections ◽  
Structural Evolution ◽  
Rift System ◽  
European Alps ◽  
Thrust Belt ◽  
Jura Mountains ◽  
Basement Faults ◽  
Fold And Thrust Belt ◽  
Spatio Temporal ◽  
Basement Structures

&lt;p&gt;The Jura Mountains are a thin-skinned fold-and-thrust belt (FTB) in the northern foreland of the European Alps, extending over northern and western Switzerland and eastern France. The Jura FTB was detached in Triassic evaporites during Late Miocene and Pliocene compression. Prior to this, the pre-Mesozoic basement was intensely pre-structured by inherited faults that had been reactivated under changing stress fields during the Mesozoic and Cenozoic structural evolution of continental Europe. In order to understand the connection between thin-skinned FTB formation and pre-existing basement structures, we compiled boreholes and geological cross-sections across the Northern Alpine Foreland and derived elevation, thickness and erosion models of defined Mesozoic units and the top of the pre-Mesozoic basement.&lt;/p&gt;&lt;p&gt;Our models confirm the presence of basement faults concealed underneath the detached cover of the Jura Mountains. The pre-Mesozoic basement shows differences in structural altitudes resulting from partially overlapping lithospheric processes. They include graben formation during evolution of the European Cenozoic Rift System (ECRIS), flexural subsidence during Alpine forebulge development and lithospheric long-wavelength buckle folding. Faults in connection with these processes follow structural trends that suggest the reactivation of inherited Variscan and post-Variscan fault systems. We discuss the spatio-temporal imprint of lithospheric signatures on the pre-Mesozoic basement and their consequence on the formation of the Jura Mountains FTB. Untangling structures within the pre-Mesozoic basement leads us to a modern understanding of the long-term evolution of the detached Mesozoic cover. Furthermore, it allows us to improve the prediction of ages that are potentially preserved within the Mesozoic cover of the Jura FTB.&lt;/p&gt;

The Oligocene–Miocene tectonic evolution of the northern Outer Carpathian fold-and-thrust belt: insights from compression-and-rotation analogue modelling experiments

2013 ◽  
Vol 150 (6) ◽  
pp. 1062-1084 ◽  
Author(s):  
MARTA RAUCH
Keyword(s):  
Tectonic Evolution ◽  
Structural Evolution ◽  
Suitable Model ◽  
Accretionary Wedge ◽  
Thrust Belt ◽  
Clockwise Rotation ◽  
The North ◽  
Analogue Modelling ◽  
Fold And Thrust Belt ◽  
Outer Carpathians

AbstractThis paper presents the different analogue scenarios of the tectonic evolution of the northern Outer Carpathians (i.e. the Western and northern Eastern Outer Carpathians) which formed as an accretionary wedge in front of the East Alpine–Carpathian–Pannonian (ALCAPA) block during Oligocene–Miocene times. Currently, this fold-and-thrust belt forms an arc which is asymmetrically convex to the north and wider in its eastern part. Palaeomagnetic investigations have suggested that the rocks of the arc underwent counter-clockwise rotation along almost the whole arc, which is difficult to explain as an effect of simple indentation of the triangular indenter. In this case two branches of the arc should be rotated in the opposite directions. The structural evolution of the Western Outer Carpathians is characterized by superposition of two successive tectonic shortening events directed N–S and NE–SW. The results of the presented analogue modelling suggest that two scenarios of the geodynamic evolution of the studied belt could explain the occurrence of such differently oriented shortening events: (1) two phases of differently directed indentation (first to the N, then to the NE) and (2) indenter movement to the NE with simultaneous counter-clockwise rotation. However, the experiment in which the moving indenter is simultaneously rotated produces the most suitable model. The counter-clockwise rotation of the material is only possible in front of both sides of the convex indenter in this model. The results of the analogue modelling also prove that rotation of the ALCAPA block started after formation of the Magura nappe (the innermost nappe of the Western Outer Carpathians).

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