scholarly journals Subsurface Structural Interpretation of Missa Keswal Area, Eastern Potwar, Pakistan

2021 ◽  
Vol 54 (1C) ◽  
pp. 146-156
Author(s):  
Muhammad Miraj
Keyword(s):  
Thrust Fault ◽  
Strike Slip ◽  
Subsurface Structure ◽  
Great Loss ◽  
Fault Surface ◽  
Sealing Mechanism ◽  
Tectonic Framework ◽  
Potwar Basin ◽  
Lockhart Limestone ◽  
Seismic Lines

Potwar Basin is although a hydrocarbon prolific basin but shows mixed scenarios regarding the success ratio of the wells. Several wells are producing good but a significant number of wells ended up with a great loss. Missa Keswal area is also a part of the Potwar Basin which was discovered in 1991. The main objective of this research is to find the subsurface structure of the Missa Keswal area with the help of seven seismic lines, 3-D modeling, and the correlation of five wells. Kingdom suite 8.8 is the main software used to delineate the subsurface structure along with some other software. Results indicate that the tectonic framework of the study area is mainly controlled by the Jhelum strike-slip fault and decollement layer i.e., Pre-Cambrian salt. Structural analysis shows that the study area bears NE-SW trending salt cored pop-up anticlinal structure bounded by major thrust fault and back thrust. Patala Formation acts as a source, Lockhart Limestone, Sakesar Limestone, and Chorgali Formation acts as a reservoir while fault surface (often acts a good conduit) and Neogene clays providing a potential sealing mechanism for entrapment.

scholarly journals Performance Evaluation of Different SAR-Based Techniques on the 2019 Ridgecrest Sequence

2021 ◽  
Vol 13 (4) ◽  
pp. 685
Author(s):  
Marco Polcari ◽  
Mimmo Palano ◽  
Marco Moro
Keyword(s):  
Performance Evaluation ◽  
Strike Slip ◽  
Seismic Sequence ◽  
Fault Rupture ◽  
Coseismic Displacement ◽  
Surface Rupture ◽  
Eastern California Shear Zone ◽  
Tectonic Framework ◽  
Gnss Network ◽  
The One

We evaluated the performances of different SAR-based techniques by analyzing the surface coseismic displacement related to the 2019 Ridgecrest seismic sequence (an Mw 6.4 foreshock on July 4th and an Mw 7.1 mainshock on July 6th) in the tectonic framework of the eastern California shear zone (Southern California, USA). To this end, we compared and validated the retrieved SAR-based coseismic displacement with the one estimated by a dense GNSS network, extensively covering the study area. All the SAR-based techniques constrained the surface fault rupture well; however, in comparison with the GNSS-based coseismic displacement, some significant differences were observed. InSAR data showed better performance than MAI and POT data by factors of about two and three, respectively, therefore confirming that InSAR is the most consolidated technique to map surface coseismic displacements. However, MAI and POT data made it possible to better constrain the azimuth displacement and to retrieve the surface rupture trace. Therefore, for cases of strike-slip earthquakes, all the techniques should be exploited to achieve a full synoptic view of the coseismic displacement field.

Types of Coal-Bearing Basin and Tectonic Unit in the Northwest Coal Hosting Area

2015 ◽  
Vol 1092-1093 ◽  
pp. 1497-1500
Author(s):  
Li Min Chen ◽  
Hao Xu ◽  
You Fei Li
Keyword(s):  
Strike Slip ◽  
Upper Triassic ◽  
Tectonic Unit ◽  
Tectonic Movement ◽  
Coal Basin ◽  
Passive Margins ◽  
Sedimentary Deposits ◽  
Coal Accumulation ◽  
Occurrence Characteristics ◽  
Tectonic Framework

Coal is typical of sedimentary deposits, Occurrence in a coal basin. The original nearly horizontal continuous coal seam was divided into different size; different depth containing coal segment by late tectonic movement, but its scope is not affected by today's "basin" restrictions. With the concept of coal occurrence tectonic unit to reflect the current Coal Occurrence Characteristics and build a prototype coal basin types that prototype into a coal basin tectonic movement after the formation of today's coal occurrence tectonic unit. In Northwest coal hosting area, the main coal bearing strata include Carboniferous-Permian, Upper Triassic, Lower-Middle Jurassic and Lower Cretaceous, and its distribution is regular; the center and strength of coal accumulation were variation in different coal-forming period; the types of basin are multiple, including Passive Margins, Peripheral Foreland, Intracontinental Rift, Intermontane, Strike-slip pull-apart, Strike-slip pull-apart, Inter-montane; moreover, one belt and two rings constitute the tectonic framework of Northwest coal hosting area.

scholarly journals Spatial and temporal distribution of slip for the 1992 Landers, California, earthquake

1994 ◽  
Vol 84 (3) ◽  
pp. 668-691 ◽  
Author(s):  
David J. Wald ◽  
Thomas H. Heaton
Keyword(s):  
Strike Slip ◽  
Quality Data ◽  
Data Sets ◽  
Rupture Velocity ◽  
Frequency Range ◽  
Fault Surface ◽  
Landers Earthquake ◽  
Finite Fault ◽  
Multiple Data Sets ◽  
Fault Length

Abstract We have determined a source rupture model for the 1992 Landers earthquake (MW 7.2) compatible with multiple data sets, spanning a frequency range from zero to 0.5 Hz. Geodetic survey displacements, near-field and regional strong motions, broadband teleseismic waveforms, and surface offset measurements have been used explicitly to constrain both the spatial and temporal slip variations along the model fault surface. Our fault parameterization involves a variable-slip, multiple-segment, finite-fault model which treats the diverse data sets in a self-consistent manner, allowing them to be inverted both independently and in unison. The high-quality data available for the Landers earthquake provide an unprecedented opportunity for direct comparison of rupture models determined from independent data sets that sample both a wide frequency range and a diverse spatial station orientation with respect to the earthquake slip and radiation pattern. In all models, consistent features include the following: (1) similar overall dislocation patterns and amplitudes with seismic moments of 7 to 8 × 1026 dyne-cm (seismic potency of 2.3 to 2.7 km3); (2) very heterogeneous, unilateral strike slip distributed over a fault length of 65 km and over a width of at least 15 km, though slip is limited to shallower regions in some areas; (3) a total rupture duration of 24 sec and an average rupture velocity of 2.7 km/sec; and (4) substantial variations of slip with depth relative to measured surface offsets. The extended rupture length and duration of the Landers earthquake also allowed imaging of the propagating rupture front with better resolution than for those of prior shorter-duration, strike-slip events. Our imaging allows visualization of the rupture evolution, including local differences in slip durations and variations in rupture velocity. Rupture velocity decreases markedly at shallow depths, as well as near regions of slip transfer from one fault segment to the next, as rupture propagates northwestward along the multiply segmented fault length. The rupture front slows as it reaches the northern limit of the Johnson Valley/Landers faults where slip is transferred to the southern Homestead Valley fault; an abrupt acceleration is apparent following the transfer. This process is repeated, and is more pronounced, as slip is again passed from the northern Homestead Valley fault to the Emerson fault. Although the largest surface offsets were observed at the northern end of the rupture, our modeling indicates that substantial rupture was also relatively shallow (less than 10 km) in this region.

Quantifying fault reactivation risk in the western Gippsland Basin using geomechanical modelling

2013 ◽  
Vol 53 (1) ◽  
pp. 255 ◽  
Author(s):  
Ernest Swierczek ◽  
Cui Zhen-dong ◽  
Simon Holford ◽  
Guillaume Backe ◽  
Rosalind King ◽  
...  
Keyword(s):  
Structural Model ◽  
Strike Slip ◽  
Fault Reactivation ◽  
Fault System ◽  
Co2 Injection ◽  
Normal Faults ◽  
Surface Geometry ◽  
Northern Margin ◽  
Fault Surface ◽  
Gippsland Basin

The Rosedale Fault System (RFS) bounds the northern margin of the Gippsland Basin on the Southern Australian Margin. It comprises an anastomosing system of large, Cretaceous-age normal faults that have been variably reactivated during mid Eocene-Recent inversion. A number of large oil and gas fields are located in anticlinal traps associated with the RFS, and in the future these fields may be considered as potential storage sites for captured CO2. Given the evidence for geologically recent fault reactivation along the RFS, it is thus necessary to evaluate the potential impacts of CO2 injection on fault stability. The analysis and interpretation of 3D seismic data allowed the authors to create a detailed structural model of the western section of the RFS. Petroleum geomechanical data indicates that the in-situ stress in this region is characterised by hybrid strike-slip to reverse faulting conditions where SHmax (40.5 MPa/km) > SV (21 MPa/km) ~ Shmin (20 MPa/km). The authors performed geomechanical modelling to assess the likelihood of fault reactivation assuming that both strike-slip and reverse-stress faulting regimes exist in the study area. The authors’ results indicate that the northwest to southeast and east-northeast to west-southwest trending segments of the RFS are presently at moderate and high risks of reactivation. The authors’ results highlight the importance of fault surface geometry in influencing fault reactivation potential, and show that detailed structural models of potential storage sites must be developed to aid risk assessments before injection of CO2.

scholarly journals First evidence of active transpressive surface faulting at the front of the eastern Southern Alps, northeastern Italy. Insight on the 1511 earthquake seismotectonics

2018 ◽  
Author(s):  
Emanuela Falcucci ◽  
Maria Eliana Poli ◽  
Fabrizio Galadini ◽  
Giancarlo Scardia ◽  
Giovanni Paiero ◽  
...  
Keyword(s):  
Strike Slip ◽  
Southern Alps ◽  
Strike Slip Fault ◽  
Fault System ◽  
The Past ◽  
Fold And Thrust Belt ◽  
Northeastern Italy ◽  
Dextral Strike Slip Fault ◽  
Seismic Lines ◽  
Dextral Strike Slip

Abstract. We investigated the eastern corner of northeastern Italy, where the NW-SE trending dextral strike-slip fault systems of western Slovenia intersects the south-verging fold and thrust belt of the eastern Southern Alps . The area suffered the largest earthquakes of the region, among which are the 1511 (Mw 6.3) event and the two major shocks of the 1976 seismic sequence, with Mw = 6.4 and 6.1 respectively. The Colle Villano thrust and the Borgo Faris-Cividale strike-slip fault have been first analyzed by interpreting industrial seismic lines and then by performing morpho-tectonic and paleoseismological analyses. These different datasets indicate that the two structures define an active, coherent transpressive fault system that activated twice in the past two millennia, with the last event occurring around the 15th–17th century. The chronological information, and the location of the investigated fault system suggest its activation during the 1511 earthquake.

Time evolution of stress under an artificial lake and its implication for induced seismicity

1978 ◽  
Vol 15 (9) ◽  
pp. 1526-1534 ◽  
Author(s):  
R. J. Withers ◽  
E. Nyland
Keyword(s):  
Induced Seismicity ◽  
Time History ◽  
Normal Fault ◽  
Thrust Fault ◽  
Strike Slip ◽  
Loading History ◽  
Failure Envelope ◽  
Artificial Lake ◽  
Coulomb Failure ◽  
History Of

The time history of stress beneath a realistic artificial lake with a realistic loading history on a permeable lithosphere can be calculated by solving the consolidation equations for a uniform permeable medium. The evolution of stress conditions towards or away from a Mohr–Coulomb failure envelope illustrates that highest risk of induced seismicity exists at initial loading and in some cases after a down-draw of the lake. The calculated histories depend crucially on hydrologic and geologic conditions which are very poorly known at many artificial lakes. If the formation strengths are constant in the area of the lake, consolidation theory indicates that failure is most likely under the lake in strike-slip or normal fault regimes. If failure occurs due to loading on a thrust fault regime it will occur at an offset from the lake.

Effect of block rotation on the pitch of slickenlines

2011 ◽  
Vol 3 (1) ◽  
Author(s):  
Shunshan Xu ◽  
Ángel Nieto-Samaniego ◽  
Susana Alaniz-Álvarez ◽  
Luis Velasquillo-Martínez
Keyword(s):  
Stress Tensor ◽  
Normal Fault ◽  
Thrust Fault ◽  
Strike Slip ◽  
Far Field ◽  
Block Rotation ◽  
Calculated Stress ◽  
Stress States ◽  
Far Field Stress ◽  
Rotation Stress

AbstractRotation of faults or pre-existing weakness planes produce two effects on the slickenlines of fault planes. First, the rotation leads to changes in the pitch of slickenlines. As a result, the aspect of the pre-existing fault may change. For example, after rotation, a normal fault may show features of an oblique fault, a strike-slip fault, or a thrust fault. Second, due to rotation, stress states on the fault planes are different from those before the rotation. As a consequence some previous planes may be reactivated. For an isolated plane, the reactivation due to rotation can produce new sets of slickenlines. With block rotation, superimposed slickenlines can be generated in the same tectonic phase. Thus, it is not appropriate to use fault-slip data from slickenlines to analyze the stress tensor in a region where there is evidence of block rotation. As an example, we present the data of slickenlines from core samples in the Tunich area of the Gulf of Mexico. The results wrongly indicate that the calculated stress tensor deviates from the far-field stress tensor.

scholarly journals Geometry of Cauto-Guacanayabo basin, Cuba

Bionatura ◽  
2019 ◽  
Vol 02 (Bionatura Conference Serie) ◽  
Author(s):  
Yaniel Misael Vazquez Taset
Keyword(s):  
Middle Miocene ◽  
Middle Eocene ◽  
Strike Slip ◽  
Upper Eocene ◽  
San Luis ◽  
Upper Oligocene ◽  
New Knowledge ◽  
Eastern Cuba ◽  
The Relationship ◽  
Seismic Lines

The Cauto-Guacanayabo basin is located in the southern part of the Guacanayabo-Nipe tectonic corridor, Eastern Cuba, and records the evidence of the evolution of the Cuban Orogen. The objective of this work is to determine the geometry of the sedimentary infill of the basin, as well as the relationship between the units that constitute it. This study is based on the interpretation of several 2D seismic lines, geological data of surface and boreholes. Four tectonosequences have been defined (TSA, TSB, TSC, TSD) delimited by four regional unconformities in the basin (U-0, U-1, U-2, U-3). The TSA is formed by Charco Redondo, Puerto Boniato, Farallón Grande and San Luís formations, with ages from the middle Eocene to the upper Eocene. The Sevilla Arriba, Paso Real, Camazán and Güines formations constitute the TSB; its age varies between the upper Oligocene and the middle Miocene. The TSC covers a period of age between the middle Miocene and the lower Pliocene and is composed of the Cabo Cruz and Manzanillo formations. The TSD is formed by the Río Maya, Dátil, Bayamo, Cauto, Jaimanitas, Villarroja, Río Macío, and Jutia formations, and the informal stratigraphic unit Marga Demajagua. The age of this tectonosequence varies between the upper Pliocene and the Holocene. This study brings new knowledge about Cuban synorogenic strike-slip basins. In addition, it allows us to understand how the complexity and compartmentalization of the sedimentary infill of the basin are the results of the evolution of the Cauto-Nipe sinistral strike-slip fault.

scholarly journals Variation of the Anticlines Vergency in the Iraqi Zagros Folds Belt and Its Tectonic Indications

2020 ◽  
Vol 25 (2) ◽  
pp. 64
Author(s):  
Ayyed Hussein Ward ◽  
Thair Mudhir Fahmi ◽  
Hasnaa Saleh Khalaf
Keyword(s):  
Thrust Fault ◽  
Thrust Belt ◽  
Fold Belt ◽  
Fault Surface ◽  
Northern Iraq ◽  
Tectonic Development ◽  
The Relationship

Folds of northern Iraq are considered integral part for the Western Zagros Fold – Thrust Belt. The growth of these folds was due to inversion displacement on inherited listric faults. This research deal with the relationship between the folds vergency and the faults that propagated folds, where that the dip of the back limb (gentle limb) for the fold is parallel to the thrust fault surface that propagated the fold, and the vergency of the fold determined by the forelimb (steep limb) situation. As a results, the folds of the high folded zone and of the western part of the low folded zone showed suture ( N and NE) vergency and foreland (S and SW) vergency, while the eastern part of the low fold zone showed foreland (S and SW) vergency only. The appearance of the suture and foreland vergency within the high folds considered as indication to the high tectonic development conformable with the location of these folds in the Iraqi Zagros Fold Belt, while the appearance of the suture and foreland vergency in the western part of the low folded zone attributed to the more tectonic development of this part in comparison with the eastern part of the zone that there folds appeared foreland vergencies only, or to the influence of the evaporite beds for Fatha formation in this part.          http://dx.doi.org/10.25130/tjps.25.2020.031

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