scholarly journals Differential Erosion and Sedimentation Process at the Longmenshan Foreland Basin, Eastern Margin of the Tibetan Plateau: Evidence From Analog Experiments

2021 ◽  
Vol 9 ◽  
Author(s):  
Qiang Luo ◽  
Bin Deng ◽  
Huiyou Guan ◽  
Yu He ◽  
Hongbin Guo ◽  
...  

We use analog experiments to investigate the influence of rapid filling of a foreland basin system during the development of a fold-and-thrust belt, in particular, the change of erosion–sedimentation along the strike in the Longmenshan foreland basin. A negative relationship between wedge geometries and the magnitude of erosion can be found; increased erosion results in out-of-sequence thrusting and fault reactivation in the wedge hinterland, to limit the forelandward propagation of the wedge. In contrast, increased sedimentation facilitates the forelandward propagation of the wedge. We focus on a natural example of the Longmenshan foreland basin, where a change in erosion–sedimentation along the strike during the Late Cretaceous to Cenozoic is well documented. The comparison between our model and seismic sections indicates that such along-strike variation results in a rejuvenated foreland basin restricted to the southwestern part of the western Sichuan Basin in the Cenozoic.

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 ◽  
...  

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.


2021 ◽  
Author(s):  
Monia Sabbatino ◽  
Stefano Tavani ◽  
Stefano Vitale ◽  
Amerigo Corradetti ◽  
Lorenzo Consorti ◽  
...  

<p>The Apennines form an active fold and thrust belt that develops as part of the W-Mediterranean subduction zone. The evolution of the collisional system is driven by the retreating subduction of the alpine Tethys, which has caused the migration of compressive fronts and the opening of the Liguro-Provençal and Tyrrhenian back-arc basins, along with the rotation and translation of the Sardinia-Corsica and Calabria blocks. The Apennines make the northern limb of the Apennines-Calabria-Sicily orocline, developed due to the differential SE-ward retreat of the subduction system. In such a context, the central-southern Apennine system develops a foreland basin floored by a subaerial forebulge unconformity followed by a trinity of diachronous lithostratigraphic units: (i) shallow-water carbonates, (ii) hemipelagic marls, and (iii) siliciclastic turbidites. Previous studies have used the following datasets for reconstructing the evolution of the orogenic-foreland basin system: paleomagnetic data;  the age of the siliciclastic syn-orogenic deposits filling the foredeep and wedge-top depozones; the age of the late-orogenic extensional basins. In this study, we highlight the importance of dating with high precision the onset of the Apennine orogenesis by means of Sr-isotope stratigraphy applied to the first carbonate sediments overlying the forebulge unconformity. In this regard, we have investigated a transect of the Apennine belt, extending from inner to outer sectors, in order to constrain the timing and style of migration of the belt and foreland basin. Our results show progressive rejuvenation of the forebulge unconformity toward the outer portions of the belt. More importantly, we highlight a time delay between the onset of syn-orogenic shallow-water carbonate deposition and the onset of siliciclastic turbidite deposition that ranges between 1 and 11 myr. In detail, the trends in the delay point at three main evolutive steps: 1) rapid evolution from forebulge to foredeep during the Burdigalian, 2) higher delays from the Serravallian until the latest Miocene, and 3) progressive decrease of the delay from the Zanclean. We associate the different velocity of migration with the differential slab retreat and spreading of the back-arc basins.</p>


2015 ◽  
Vol 186 (4-5) ◽  
pp. 273-290 ◽  
Author(s):  
Maurizio Gasparo Morticelli ◽  
Vera Valenti ◽  
Raimondo Catalano ◽  
Attilio Sulli ◽  
Mauro Agate ◽  
...  

Abstract Neogene-Quaternary wedge-top-basins arose during the Sicilian fold and thrust belt (FTB) build-up. The infilling sedimentary successions are: i) middle-upper Miocene silicoclastics succession, accommodated on top of the accreted Sicilide and Numidian flysch nappes; ii) upper Miocene-lower Pliocene deepening-upwards sediments unconformably overlying the inner Meso-Cenozoic deep-water, Imerese and Sicanian thrust units; iii) Upper Pliocene-Quaternary coastal-open shelf deposits unconformably covering (in the outer sector of the FTB) a tectonic stack (Gela thrust system). These successions are characterized by a basal unconformity on the deformed substrate believed to be the depositional interface common both to the coeval wedge-top and foredeep basins. The tectono-sedimentary evolution of the syn-tectonic basins was controlled by the progressive deepening of the structural levels, which were active during the growing of the FTB. The palinspastic restoration of a crustal geological transect in central Sicily points to: i) the occurrence of two subsequent, basal main thrusts (MT1 and MT2) active during the Neogene-middle Pleistocene tectonic evolution, as well as ii) a decrease in slip- and shortening-rate, estimated for the later MT2 as compared to earlier MT1 basal main thrust. The foreland-basin system evolution recorded during these two steps suggests: – the regional lithofacies distribution, during late Tortonian-early Pliocene, accounted for a wide depozone including the Iblean plateau and its offshore;– a crucial change was recorded by the late Pliocene-Pleistocene wedge-top depozone, when the deeper basal main thrust (MT2) involved and thickened (in the inner sector of the FTB) the crystalline basement (thin- to thick-skinned thrust tectonics); this change influenced the depozones, progressively narrowing up to the present-day setting. As regards this general evolutionary framework, thin-skinned and thick-skinned thrust tectonics can be recognized in the Sicilian FTB evolution. The late Tortonian-early Pliocene, thin-skinned thrust tectonics include two main tectonic events, a “shallow-seated” Event 1 and a “deep-seated” Event 2, with the Pliocene-Pleistocene thick-skinned thrust tectonics representing a third tectonic event (Event 3).


Sign in / Sign up

Export Citation Format

Share Document