The Fault Analysis Projection System (FAPS) - A new seismic interpretation and structural geological interpretation tool.

1989 ◽  
Vol 20 (2) ◽  
pp. 1
Author(s):  
B. Freeman ◽  
M. Badley ◽  
G. Yielding
Keyword(s):  
Seismic Interpretation ◽  
Strike Slip ◽  
Fault Analysis ◽  
Normal Faults ◽  
Simple Task ◽  
Projection System ◽  
Geological Interpretation

Recent research has demonstrated that the displacement on faults varies in a systematic manner, both vertically and laterally. Contours of displacement on strike projections display ordered patterns for isolated normal faults, strike-slip faults and syn-sedimentary faults. Recognition of these ordered patterns forms the basis for a new seismic interpretation and structural/geological interpretation tool, enabling objective verification of fault correlation, identification of bad fault or horizon picks, and a better understanding of the overall kinematic framework. The Fault Analysis Projection System (FAPS) is a computerized implementation of this technique designed to run on UNIX-based workstations. The FAPS uses the X-windows graphics system which permits different elements of the interpretation/analysis to be viewed at the same time and is designed to make adjustments to interpretations a simple task. For example, an interpreter may work on a map in one window, a set of sections in another window, perform a graphics screen-edit on data in a third window and view the results of an analysis in a separate, fourth window.

Rampart seismic zone of central Alaska

1983 ◽  
Vol 73 (3) ◽  
pp. 813-829
Author(s):  
P. Yi-Fa Huang ◽  
N. N. Biswas
Keyword(s):  
Main Shock ◽  
Fault Plane ◽  
B Value ◽  
Aftershock Sequence ◽  
Strike Slip ◽  
Lithospheric Plate ◽  
Normal Faults ◽  
Seismic Zone ◽  
The West ◽  
Fault Plane Solutions

abstract This paper describes the characteristics of the Rampart seismic zone by means of the aftershock sequence of the Rampart earthquake (ML = 6.8) which occurred in central Alaska on 29 October 1968. The magnitudes of the aftershocks ranged from about 1.6 to 4.4 which yielded a b value of 0.96 ± 0.09. The locations of the aftershocks outline a NNE-SSW trending aftershock zone about 50 km long which coincides with the offset of the Kaltag fault from the Victoria Creek fault. The rupture zone dips steeply (≈80°) to the west and extends from the surface to a depth of about 10 km. Fault plane solutions for a group of selected aftershocks, which occurred over a period of 22 days after the main shock, show simultaneous occurrences of strike-slip and normal faults. A comparison of the trends in seismicity between the neighboring areas shows that the Rampart seismic zone lies outside the area of underthrusting of the lithospheric plate in southcentral and central Alaska. The seismic zone outlined by the aftershock sequence appears to represent the formation of an intraplate fracture caused by regional northwest compression.

Late Pleistocene extension and strike-slip in the Dead Sea Basin

2004 ◽  
Vol 141 (5) ◽  
pp. 565-572 ◽  
Author(s):  
YUVAL BARTOV ◽  
AMIR SAGY
Keyword(s):  
Internal Structure ◽  
Slip Rate ◽  
Dead Sea ◽  
Strike Slip ◽  
Normal Faults ◽  
Small Scale ◽  
Dead Sea Basin ◽  
Pull Apart Basin ◽  
Western Border ◽  
The Dead

A newly discovered active small-scale pull-apart (Mor structure), located in the western part of the Dead Sea Basin, shows recent basin-parallel extension and strike-slip faulting, and offers a rare view of pull-apart internal structure. The Mor structure is bounded by N–S-trending strike-slip faults, and cross-cut by low-angle, E–W-trending normal faults. The geometry of this pull-apart suggests that displacement between the two stepped N–S strike-slip faults of the Mor structure is transferred by the extension associated with the normal faults. The continuing deformation in this structure is evident by the observation of at least three deformation episodes between 50 ka and present. The calculated sinistral slip-rate is 3.5 mm/yr over the last 30 000 years. This slip rate indicates that the Mor structure overlies the currently most active strike-slip fault within the western border of the Dead Sea pull-apart. The Mor structure is an example of a small pull-apart basin developed within a larger pull-apart. This type of hierarchy in pull-apart structures is an indication for their ongoing evolution.

scholarly journals Cenozoic tectonic model of the Bohai Bay Basin in China

2016 ◽  
Vol 153 (5-6) ◽  
pp. 866-886 ◽  
Author(s):  
FUSHENG YU ◽  
HEMIN KOYI
Keyword(s):  
Data Interpretation ◽  
Strike Slip ◽  
Normal Faults ◽  
Bohai Bay ◽  
Bohai Bay Basin ◽  
Basin Inversion ◽  
Tectonic Model ◽  
Early Oligocene ◽  
Anticlockwise Rotation ◽  
Partial Inversion

AbstractModelling results and seismic interpretation illustrate that the Cenozoic evolution of the Bohai Bay Basin (BBB) can be divided into different stages. A transtensional phase during Paleocene – early Oligocene time created NE-trending strike-slip faults and E–W-trending normal faults which were driven roughly by N–S–extension, making an angle of 25° with the strike-slip faults. Seismic data interpretation yields evidence that inversion phases occurred within the NE Xialiaohe Depression of the greater Bohai Bay Basin. This inversion phase is attributed to rotation and partial inversion that occurred during late Oligocene time, leading to formation of inversion structures along the NE part of Tanlu Fault. This episode is attributed to an anticlockwise rotation of the eastern part of the BBB driven by the convergence between the Pacific and Eurasian plates. The tectonic scenario described was simulated in scaled analogue models, which were extended by pulling two basement plates away from each other. Partial inversion was simulated by rotation of one of the plates relative to the other. Model results show many of the features observed in the BBB. Our model results are used to argue that, unlike the two-episode extension and whole-basin inversion models previously proposed for the BBB, a single N–S-aligned extension followed by anticlockwise rotation accounts for the Cenozoic evolution of the BBB and produces some of the structural complexities observed in the basin.

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.

X.—A Gravity Survey in Ayrshire and its Geological Interpretation

1966 ◽  
Vol 66 (10) ◽  
pp. 239-265 ◽  
Author(s):  
Adam C. McLean
Keyword(s):  
Gravity Field ◽  
Bouguer Anomaly ◽  
Gravity Survey ◽  
Normal Faults ◽  
Red Sandstone ◽  
Geological Interpretation ◽  
The North ◽  
Close Relationship ◽  
Lower Palaeozoic ◽  
Western Limb

SynopsisBouguer anomaly maps covering most of Ayrshire at a density of about one station per sq. km., show a close relationship between anomalies and the distribution of the Upper Palæozoic rocks in the area south of the Inch-gotrick Fault, but are less clearly interpreted to the north, where thick dense igneous masses are present.In central and south Ayrshire the gravity field may be largely interpreted in terms of the known density-contrasts at the interfaces separating Upper and Lower Old Red Sandstone, and Lower Old Red Sandstone and Lower Palæozoic rocks. The major structure, the Mauchline Basin, is reflected clearly in the largest anomaly, and there is evidence of a culmination of its south-western limb near Kirkoswald. The important N.E.–S.W. faults also give rise to large anomalies, which may be connected with the known geology. It is inferred that they moved as normal faults in Carboniferous times, and that the adjacent synclines are essentially sags associated with the fault displacements. There is geophysical evidence that both the Southern Upland and Kerse Loch Faults existed in Middle O.R.S. (proto-Armorican) times. It is concluded that a hypothesis of N.–S. Armorican stress is not valid in south Ayrshire.In north Ayrshire, many of the anomalies are best explained by changes of thickness of the Millstone Grit lavas and of the Clyde Plateau lavas, and by the presence of thick dolerite intrusions. Additional evidence is needed, however, before final conclusions may be drawn.

Seismic and geodetic response to crustal deformation in Krísuvík volcanic system, southwest Iceland

2020 ◽  
Author(s):  
Revathy M. Parameswaran ◽  
Ingi Th. Bjarnason ◽  
Freysteinn Sigmundsson
Keyword(s):  
Stress Field ◽  
Crustal Deformation ◽  
High Energy ◽  
Strike Slip ◽  
Normal Faults ◽  
Seismic Zone ◽  
The South ◽  
The West ◽  
Volcanic System ◽  
Geothermal Activity

<p>The Reykjanes Peninsula (RP) is a transtensional plate boundary in southwest Iceland that marks the transition of the Mid-Atlantic Ridge (MAR) from the offshore divergent Reykjanes Ridge (RR) in the west to the South Iceland Seismic Zone (SISZ) in the east. The seismicity here trends ~N80°E in central RP and bends to ~N45°E at its western tip as it joins RR. Seismic surveys, geodetic studies, and recent GPS-based kinematic models indicate that the seismic zone is a collection of strike-slip and normal faults (e.g., Keiding et al., 2008). Meanwhile, the tectonic processes in the region also manifest as NE-SW trending volcanic fissures and normal faults, and N-S oriented dextral faults (e.g., Clifton and Kattenhorn, 2006). The largest of these fissure and normal-fault systems in RP is the Krísuvík-Trölladyngja volcanic system, which is a high-energy geothermal zone. The seismicity here predominantly manifests RP’s transtentional tectonics; however, also hosts triggered events such as those following the 17 June 2000 Mw6.5 earthquake in the SISZ (Árnadottir et al., 2004) ~80 km east of Krísuvík. Stress inversions of microearthquakes from 1997-2006 in the RP indicate that the current stress state is mostly strike-slip with increased normal component to the west, indicating that the seismicity is driven by plate diverging motion (Keiding et al., 2009). However, the geothermal system in Krísuvík is a potential secondary source for triggered seismicity and deformation. This study uses seismic and geodetic data to evaluate the activity in the Krísuvík-Trölladyngja volcanic system. The seismic data is used to identify specific areas of focused activity and evaluate variations in the stress field associated with plate motion and/or geothermal activity over space and time. The data used, within the time period 2007-2016, was collected by the the South Icelandic Lowland (SIL) seismic network operated and managed by the Iceland Meterological Office (IMO). Furthermore, variations in seismicity are compared to crustal deformation observed with TerraSAR-X images from 2009-2019. Crustal changes in the Krísuvík area are quantified to develop a model for corresponding deformation sources. These changes are then correlated with the stress-field variations determined with seismic analysis.</p>

High resolution imaging of fault reactivation in long-lived extensional setting: a case study from the Exmouth Plateau (NW Australia)

2020 ◽  
Author(s):  
Nico D'Intino
Keyword(s):  
High Resolution ◽  
Confining Pressure ◽  
Data Interpretation ◽  
Fault Analysis ◽  
Fault Reactivation ◽  
Normal Faults ◽  
3D Seismic ◽  
Exmouth Plateau ◽  
Northern Carnarvon Basin ◽  
Nw Australia

<p>Extension in rift zones and passive margins often occur by multiphase normal faulting which usually accommodates several episodes of lithosphere stretching by brittle deformation. In these settings, pre-existing normal faults may reactivate but also new-formed structures may nucleate, with multiple orientations and deformational styles. The various modes of fault growth and nucleation are strongly influenced by several parameters (including orientation and geometry of pre-existing discontinuities, stress orientation and magnitude, strain rates, confining pressure, etc..) with the lithostratigraphy controlling the brittle or ductile litho-mechanic behavior of each unit.</p><p>In this work, we interpreted and analyzed an industrial 3D seismic volume acquired in the Exmouth Plateau, (Northern Carnarvon Basin – offshore NW Australia), where pre-existing Mesozoic normal faults were reactivated during the Cenozoic and controlled the nucleation and growth of the new-formed overlying fault segments. The peculiarity of this system is that the two sets of faults are separated by a ductile interval of shales. The latter acted as decollement level and promoted the formation of prominent faulted anticlines in the overlying brittle sequence; these forced folds are poorly documented in other extensional settings while are common where salt layers are present. In this study, the high-resolution techniques adopted for seismic data interpretation aimed to understand the geometries of faults and their interactions in fine detail. The results of fault analysis suggest that the use of high-quality 3D seismic volumes is very useful to unravel the complex and subtle spatial variability and also the displacement pattern of faults with a limited amount of fault-throw.</p>

Pre-, syn-, and post-imbrication deformation of carbonate slices along the southern Quebec Appalachian front – implications for hydrocarbon exploration

2007 ◽  
Vol 44 (4) ◽  
pp. 543-564 ◽  
Author(s):  
Stephan Séjourné ◽  
Michel Malo
Keyword(s):  
Strain Relaxation ◽  
Structural Features ◽  
Strike Slip ◽  
Hydrocarbon Exploration ◽  
Normal Faults ◽  
Structural Style ◽  
Slip Planes ◽  
Bed Thickness ◽  
Seismic Scale ◽  
Extensional Structures

Thrust-imbricated shelf-carbonate slices form a wide but poorly understood part of the southernmost Quebec Appalachian structural front. Comprehensive structural analysis of two slices exposed at surface, the Saint-Dominique and Philipsburg slices, shows that pre- and post-imbrication structures are important in defining the final architecture of the slices. The dominant structural style is characterized by thrusts and associated asymmetrical folds, tear faults, oblique ramps and incipient backthrusts developed during WNW–ESE shortening. A forward-breaking (piggy-back) sequence of thrusting is recognised, as well as minor out-of-sequence thrusting. The complexity and diversity of contractional structures is directly influenced by lithology (bed thickness and shale content). Bedding-parallel slip planes are important in the concentration (activation and reactivation) of deformation, in that there are the loci for veining, faulting, and folding. Recognition of lithostructural units provides guidelines for the identification of sub-seismic-scale structural traps in subsurface investigations. Extensional structures (normal faults, veins, tension gashes) are found within all carbonate slices, as well as within the footwall of their basal thrusts. Only a few pre-imbrication normal faults have been identified, one of which is a growth fault. Post-imbrication extensional structures are linked with strain relaxation after overthrusting. A widespread front-parallel strike-slip faulting event postdates all other structural features and can have a major impact on the compartmentalization of potential hydrocarbon reservoirs.

Transfer Zone Characteristics in No. II Fault Zone and its Control on Petroleum, TaZhong Area

2011 ◽  
Vol 356-360 ◽  
pp. 3009-3015
Author(s):  
Yu Hang Zhang ◽  
Xing Yan Li ◽  
Zhi Feng Yan
Keyword(s):  
Fault Zone ◽  
Oil And Gas ◽  
Structural Evolution ◽  
Strike Slip ◽  
Fault Analysis ◽  
Seismic Profiles ◽  
Oil And Gas Exploration ◽  
Detachment Faults ◽  
Tazhong Area ◽  
Transfer Zone

According to interpreted cautiously with 2D and 3D seismic profiles, the typical transfer zone was identified in No.Ⅱ fault zone of TaZhong area, near the TaZhong 46 well of central uplift belt in Tarim basin. Discussed the transfer zone characteristic on the basis of seismic interpretation, it’s clearly triangle transfer zone and caused by strike-slip affection. Using structural analysis method, it is indicated that the transfer zone composed by thrusting-detachment faults. According to structural evolution analysis, the transfer zone had been affecting constantly by transpression during the caledonian-late hercynian, Analyzing geologic setting and regional geology characteristic, TaZhong No.Ⅱ fault zone are sinistral transpression strike-slip fault. Analysis the control action of transfer zone’s for trap, reservoir, hydrocarbon migration and sedimentary, the Transfer zone have the advantage target for oil and gas exploration.

scholarly journals A case study on semiautomatic seismic interpretation of unconformities and faults in the southwestern Barents Sea

2018 ◽  
Vol 6 (2) ◽  
pp. SD29-SD40 ◽  
Author(s):  
Aina J. Bugge ◽  
Stuart R. Clark ◽  
Jan E. Lie ◽  
Jan I. Faleide
Keyword(s):  
Barents Sea ◽  
Seismic Interpretation ◽  
Connected Components ◽  
Normal Faults ◽  
Morphological Operations ◽  
Image Region ◽  
The North ◽  
Seismic Amplitudes ◽  
Cenozoic Sediments

Recently, there has been a growing interest in automatic and semiautomatic seismic interpretation, and we have developed methods for extraction of 3D unconformities and faults from seismic data as alternatives to conventional and time-consuming manual interpretation. Our methods can be used separately or together, and they are time efficient and based on easily available 2D and 3D image-processing algorithms, such as morphological operations and image region property operations. The method for extraction of unconformities defines seismic sequences, based on their stratigraphic stacking patterns and seismic amplitudes, and extracts the boundaries between these sequences. The fault-extraction method extracts connected components from a coherence-based fault-likelihood cube where interfering objects are addressed prior to the extraction. We have used industry-based data acquired in a complex geological area and implemented our methods with a case study on the Polhem Subplatform, located in the southwestern Barents Sea north of Norway. For this case study, our methods result in the extraction of two unconformities and twenty-five faults. The unconformities are assumed to be the Base Pleistocene, which separates preglacial and postglacial Cenozoic sediments, and the Base Cretaceous, which separates the severely faulted Mesozoic strata from prograding Paleocene deposits. The faults are assumed to be mainly Jurassic normal faults, and they follow the trends of the eastern and southwestern boundaries of the Polhem Subplatform; the north–south-trending Jason Fault complex; and the northwest–southeast-trending Ringvassøy-Loppa Fault complex.

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