Late Mesozoic–Cenozoic décollement structure and its deep geological background in western Shandong, China

Li, Li; Zhong, Dandan; Shi, Xuhua; Tang, Zibo; Hu, Qiuyuan; Xu, Yi; Li, Zhiwei

doi:10.1016/j.pnsc.2008.08.006

Cited by 13 publications

(4 citation statements)

References 10 publications

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“…Apart from the fracture cut across the bedding surface, several bed-parallel fractures were observed in the core (Figure 2E), most of which developed along the bedding surface. Some were diagenetic or contracted fractures, while others resulted from the structural replacement of the bedding surface under tectonic action (Li et al, 2009).…”

Section: Core Fracture Characteristics Of Single Wellsmentioning

confidence: 99%

Relationship between the heterogeneity of low-permeability reservoirs and the dynamic evolution of fractures under uniaxial compression conditions by CT scanning: A case study in the jiyang depression of Bohai Bay Basin, China

Shi

Zhang

et al. 2023

Front. Earth Sci.

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Based on an analysis of core fractures and computed tomography scanning by X-ray under uniaxial compression tests with loading and unloading, this study investigated the three-dimensional evolution of fracture initiation and propagation in different heterogeneity conditions of low-permeability reservoirs. Reservoir heterogeneity affected the 3D dynamic development of fractures. With increasing loading value, fractures with strong heterogeneity in low-permeability reservoirs followed the development sequence from shallow to deep depth in the profile. When the fracture tip reached the incompetent layer, propagation stopped. Subsequently, when the deformation continued to increase, the fracture crossed the incompetent layer and initiated a new fracture at the front end. Therefore, the across-bedding and through-going macro fractures formed in conjugate sets or were Y-shaped, with roughly equal spacing. In the plane, the fractures initiated along the pre-existing bedding parallel fracture and further propagated into large fractures. Consequently, they formed a net-shaped fracture from the edge to the center, with a long development period. These fractures intersected to form a complex, interconnected, and high-fracture-density system in three dimensions. Under the same loading value, owing to uniform lithology, the formation of micro-fractures in the weak heterogeneity of low-permeability reservoirs is difficult. Furthermore, long shear fractures were only produced in a relatively short formation period with a low fracture density. In the plane, the fractures stepped in an en-énchelon and terminated with horse-tailing microfractures. Moreover, the strong heterogeneity of low-permeability reservoirs was more favorable for producing fractures. The fracture volume was 13.17% of the total sample volume compared to 0.67% in the weak-heterogeneity reservoir under the same loading compression. Furthermore, a better fracturing effect was achieved by fracturing along the direction >50° with the natural fracture and under the condition of small differential horizontal stresses.

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Section: Core Fracture Characteristics Of Single Wellsmentioning

confidence: 99%

Relationship between the heterogeneity of low-permeability reservoirs and the dynamic evolution of fractures under uniaxial compression conditions by CT scanning: A case study in the jiyang depression of Bohai Bay Basin, China

Shi

Zhang

et al. 2023

Front. Earth Sci.

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“…Geophysical data indicate that there is a brittle‐ductile transition at the bottom of the upper crust (7–11 km) in the Luxi Block, for which the shallow crust is a brittle structural level while the deep crust is a ductile structural level. The transition zone plays an important role in the transmission of lithospheric stress from deep to shallow depth, and it is the main accommodation interface between deep and shallow deformation (Li et al, ). In this paper, we argue that the tomographic image at 30 km depth should be explained by density differences or compositional differences in the crust.…”

Section: Deep‐seated Structuresmentioning

confidence: 99%

Cenozoic faulting response of eastern North China to subduction of the Pacific Plate: A case of study of the Luxi Block

Wang

et al. 2017

Geological Journal

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The Cenozoic deformation and dynamic evolution of the eastern part of North China were significantly affected by the changing of the subduction direction and rate of the Pacific Plate. In this paper, we use the Luxi Block as a specific case study area, by examining the Cenozoic structural connection between the deep and shallow levels, and the related seismicities and their triggering mechanisms. We investigate the response of the Cenozoic tectonic activities in this area to the subduction of the Pacific Plate. The results show that the Cenozoic shallow fault pattern in the Luxi Block is mainly characterized by a domino‐style normal fault pattern constituted by a series of NW‐ to WNW‐trending normal faults. The focal mechanism and field observations suggest that these faults are sinistral strike‐slip type, and they dominate the formation and development of the Cenozoic basins jointly controlled by the NE‐trending faults. Geophysical data suggest that at a depth of 15–20 km beneath the Luxi Block, there is a gentle décollement zone and large‐scale low‐velocity tomographic anomalies. The domino‐style fault system in the shallow crust is incorporated into this décollement zone, manifesting as a decoupling between the shallow and deep structures, and a transition zone between the high‐ and low‐velocity anomaly zones controlling the development of two medium to strong NW‐trending earthquake zones. With respect to the dynamic mechanisms, the tectonic activities in eastern North China are closely related to the subduction of the Pacific Plate, which induced crustal thinning, mantle upwelling and small‐scale convections in the mantle wedge, and also caused the uplift of the Luxi Block.

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“…Les empilements épais Les plis isoclinaux, serrés et renversés sont des structures communes aux bassins piggyback (de Wit, 1982;Lucchi, 1990;Lucente, 2004;Parish, 1984). Les plis asymétriques constituent une manifestation en surface de structures associées à un décollement (Li et al, 2009). Selon Li et al, (2009), le décollement est initié par un soulèvement rapide dérivé de la subduction.…”

Section: 4-modèle Paléogéographique Et Tectoniqueunclassified

“…Les plis asymétriques constituent une manifestation en surface de structures associées à un décollement (Li et al, 2009). Selon Li et al, (2009), le décollement est initié par un soulèvement rapide dérivé de la subduction.…”

Section: 4-modèle Paléogéographique Et Tectoniqueunclassified

Caractéristiques sédimentologiques, volcanologiques et structurales du bassin de Granada dans la ceinture de roches vertes de l'Abitibi (Québec) /

Diop¹

2011

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The Granada Basin, correspond to the stratigraphie unit known as the Granada Formation. This unit lies in the southernmost part of the Southern Volcanic Zone of the greenstone dominated Abitibi Subprovince in Quebec.Faciès analysis in the Granada Basin has identified clastic and volcaniclastic rocks deposited in an environment evolving from relatively deep marine to fluvial. The earliest sediments were mainly turbidites (faciès la and lb) deposited in extensional sub-basins. These sediments were overlain by a regressive sequence that evolved from shallow marine wave base dominated sediments (faciès 2a) to coastal deposits (faciès 2b). These deposits represent the transition between marine and continental depositional environments. The transition zone is marked by deposits of sandstoneargillites-stratified pebble conglomerate (faciès 2b) transported by waves and tides between the subtidal and intertidal zone. Faciès 3a and 3b of the felsic volcaniclastic lithofacies are interbedded with faciès la, lb and 2a.Deposits of the Granada Basin are transitional faciès separated by intra-basin unconformities, which are characteristic of sedimentary basins formed along fault margins. The volcano-sedimentary deposits of the Granada Basin have characteristics of sedimentation influenced by tectonisme such as: i) local and basinwide lateral and vertical faciès variations; ii) alternating fining and coarsening upwards sequences; iii) high rate of accumulation of sediments; iv) some conglomerate boulders are over 1 m in size and the thickness of conglomerate deposits; v) interdigitation of conglomerates and sandstones that denotes a progradation; vi) intra-basin unconformities; vii) the local source of conglomerates; and viii) associated alkaline magmatism. Tectonism would be ongoing throughout the development of the basin which would have induced several phases of source renewal areas for the sediments coupled with intra-basin unconformities. The earliest formed sedimentary deposits of the Granada Basin were affected by uplift and subsequently eroded and recycled into later basin fill along intra-basin unconformities. Gradually as the basin filled the sedimentary deposits became less and less shallower which is a characteristic of piggyback-type basins. The decrease in the depth is a consequence of an increase in topography due to repeated uplift along faults.Sedimentary rocks of the Granada Basin were intruded by alkalic mature volcanic arc-type sills, stocks and porphyritic dikes. These intrusive rocks are similar to Timiskaming-type porphyry intrusions and volcanic rocks found in the Kirkland Lake area of Ontario.The structural style of the Granada Basin, consisting of overturned southward verging tight to isoclinal folds, is characteristic of thrust basins. Two major east-west trending synclinal axial traces are distinguishable and their juxtaposition in a back to back relationship is compatible with there being an unconformity between them. This unconformity is further demonstrated by the presence of sandstone cla...

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Late Mesozoic–Cenozoic décollement structure and its deep geological background in western Shandong, China

Cited by 13 publications

References 10 publications

Relationship between the heterogeneity of low-permeability reservoirs and the dynamic evolution of fractures under uniaxial compression conditions by CT scanning: A case study in the jiyang depression of Bohai Bay Basin, China

Relationship between the heterogeneity of low-permeability reservoirs and the dynamic evolution of fractures under uniaxial compression conditions by CT scanning: A case study in the jiyang depression of Bohai Bay Basin, China

Cenozoic faulting response of eastern North China to subduction of the Pacific Plate: A case of study of the Luxi Block

Caractéristiques sédimentologiques, volcanologiques et structurales du bassin de Granada dans la ceinture de roches vertes de l'Abitibi (Québec) /

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