These faults were reactivated during the triassic rifting and have formed linear shear zones that are affecting structural and sedimentary systems to present day. Backstripping can be applied on its own, or by combining it with. Lacustrine megaturbidites in an intermontane strike slip basin. Compression and rotation in the cuyama valley, ca1ifornia. The oldest faults along the extensional portion of the bend are dominantly strikeslip, and they strike 15w from the main strike of the karakoram fault. Geology and magmatichydrothermal evolution of the giant. These faults merge downward with the san pedro basin fault zone, which is nearly vertical and strike slip.
Strikeslip deformations in the west siberian basin and. The point source inversion supports a shallow strikeslip earthquake with a centroid at 10 km depth, supporting a mechanism of slipdiprake of. Dotted rectangle shows area of interest of this article. A simple model with this assumption places the region of maximum subsidence of a stepover basin beneath the deepest part of the. Geophysical insights into the transition fault debate. Strike slip offset of qg is equal to total offset on the coyote creek fault in the study area 6 km, indicating that strike slip motion on the fault began after deposition of qg, after ca. Stratigraphic record of pleistocene initiation and slip on. The whittierelsinore, san andreas, and san jacinto fault zones are strike slip faults with the potential to generate major. Petrophysical implications the strikeslip model for the jacintoparedon area implies that a new focus may need to.
The primary result of the motion along the strikeslip faults is sw translation of the thicker and older continental crust that crops out onshore lebanon toward the levant basin and structurally higher along the margin. The pullapart basin models are flatbottomed in the center of the basin and become asymmetric at either end where the sidewall fault systems join the pdz. Margin deposits debris flow fans with coarse breccias and conglomerates, abrupt facies change,high rates of sedimentation and thick sequences. Crustal thickening in gansuqinghai, lithospheric mantle. Analog modeling of pullapart basins1 aapg bulletin. Basin seems to be the combined stepover of motion on the san andreas and san gregorio faults onto the golden gate fault, leading to the creation of a transtensional strikeslip stepover basinthe san gregorio basin. This gives a timeaveraged slip rate in coyote creek of 10 mmyr. Geology of the continental margin beneath santa monica bay. Tectonics of strikeslip restraining and releasing bends geological.
Strikeslip structures in a random seismic line view. Sedimentary basins form along strikeslip faults as a result of localized crustal. Crustal thickening in gansuqinghai, lithospheric mantle subduction, and oblique, strikeslip controlled growth of the tibet plateau b. Strikeslip faulting is one of the most important mechanisms of sedimentary basin formation at plate convergent margins, where localized extension can cause. Extension of the north anatolian fault into the north aegean. Effects of this structural deformation include mountain building, basin development, widespread regional uplift, and earthquake generation. However, if a crustal extension is superimposed on ideal strike slip kinematics, the resulting strain ellipsoid has its vertical s 2 shortened relative to the ideal strike slip case, producing a prolate strain ellipsoid.
Lateral strikeslip displacement in time slice 3876 ms. Strikeslip tectonics within the sw baltic sea and its. A possible sinistral nw striking fault separates two subbasins and may indicate crustal block rotation with deformation focused in block corners. The oldest faults along the extensional portion of the bend are dominantly strikeslip, and they strike. Together with the adjacent sunda strait strike slip basin, it probably formed in response to movement along the sumatra strike slip fault fig. Pdf lacustrine megaturbidites in an intermontane strike. Strikeslip model for the jacinto and paredon fields of the. The basin formed originally as a sinistral strike slip basin 77, 86, but developed into a dextral strike slip basin after the change in the sense of fault displacement of the rrfz 87, 88. This observation and the azimuth of the regional displacement vector indicate that the north imral. In the field, strikeslip movement is indicated by abundant subhorizontal slickensides. Pullapart basin evolution is characterized by the initial development of a spindle graben bounded by oblique.
Several of the more dominant strikeslip faults merge with the. Syntectonic sedimentary features include a prominent, generally s and sedirected, progradational depositional system with the major source area provided by uplifted basement blocks, in particular by the bornholm block. Recent sandbox models have shown that the geometry and evolution of pullapart basins varies greatly in pure strike slip situations versus transtensional settings. Geodynamics of the northern andes subductions and intracontinental deformation colombia alfredo taboada, lz luis a. The salinas basin is selected as the study area for developing this methodology because of its strike slip history, and because it contains only one petroleum system. Yeats during the cenozoic, tectonics in the cuyama basin of the southeastern salinian block changed from extension to strike slip faulting to compression and rotation. The point source inversion supports a shallow strike slip earthquake with a centroid at 10 km depth, supporting a mechanism of slip diprake of 12484175 or 214855 for the nodal plane. To the west, the obliqueslip pamplona zone and transition faults merge at an embayment in the continental margin, where a northsouth dextral strikeslip fault within the paci. The major denali fault in central alaska forms the contact between the intermontane belt and the collapsed flysch basins. The study of the geology of the bornu basin has received considerable attention mainly because of its presumed hydrocarbon potential, ground water exploration and its position in. Pdf examples of each type of strikeslip basins are provided.
Structure of the submerged san andreas and san gregorio fault. Strikeslip basin its configuration and sedimentary facies. Earthquake crisis unveils the growth of an incipient. The paruro formation has been previously interpreted as a strikeslip basin carlotto, 20, as have other structures in the peruvian. However, the basin geometry is quite different from that of the ridge basin, whose shape is more elongated with a length of more than 300 km and a width of less than 20 km, and whose southern margin has been truncated by postdepositional strikeslip fault displacement. Smaller, subparallel faults are located south of the denali fault and the pebble district is located between. During the maastrichtianpaleocene time, the basin developed into a foreland basin, related to the uplift of the central cordillera. Plate tectonics information and facts national geographic. Although some workers have proposed that 100150 km of leftlateral slip occurred along this zone budnik, 1986, more recent palinspastic reconstructions in southwest oklahoma indicate that only 1226. Imaging active faulting in the western taiwan strait.
Learn vocabulary, terms, and more with flashcards, games, and other study tools. Incorporating strikeslip faulting in bpsm basin and. The basin formed originally as a sinistral strikeslip basin 77, 86, but developed into a dextral strikeslip basin after the change in the sense of fault displacement of the rrfz 87, 88. Rivera, tm andr6s fuenzalida, 5 armando cisternas, 4 herv6 philip, 1 harmen bijwaard, jos60laya, 5 and clara rivera 5 abstract.
Results will demonstrate the impact of strike slip faulting on petroleum systems in transpressional settings. They are often associated with restraining or releasing bend. The san andreas fault in california is an example of a transform boundary, where two plates grind past each other along what are called strike slip faults. However, we believe that a better model for petroleum geology, seismic risk evaluation, and. Geodynamics of the northern andes wiley online library. Strike slip deformations in the west siberian basin and their impact on oil and gas reservoirs 361 central european geology 52, 2009 fig. In the sunda strait and east and west of the honje horst structure, and north and south of west java malod et al 1996 are a series of moderately dipping half grabens which trend ns. A strike slip fault that bounds a fold and thrust belt thus accommodating the differential motion of the thrust belt from an undeformed region need not pene trate deeper than the decollement of the thrust belt. Pdf various types of sedimentary basins that contain a great variety of sedimentary successions and structural attributes form along strikeslip. The escarpment and its attendant structures diverge from this strikeslip fault zone and extend for 60 km along the margin, separating the continental shelf from the deepwater basins. Oblique and strike slip reactivated normal faults, concentrated near the northwestern and southeastern basin margins, may be related to the lateral transfer of extensional strain to adjoining basins. Connecting the tips of step over faults to the opposite fault are bounding basin sidewall faults. Sediment progradation was enhanced by downfaulting along a strike slip fault zone and related expansion of accommodation space. An integrated geophysical analysis of crustal structure in.
A regional strike slip fault is referred to as a principle displacement zone pdz. A geologic phenomenon associated with strike slip fault structures is. Dynamics of basin formation and strikeslip tectonics. At depth we might expect such zones to show a weak subhorizontal foliation and strong lineations oblique to the szb. The san andreas fault in california is an example of a transform boundary, where two plates grind past each other along what are called strikeslip faults. Stepover basins transtensional or pullapart basins c. Basins of extensional and strikeslip settings is mu. A tectonic regime combining strikeslip movement with oblique.
The sidewall faults show changes in kinematics from dominantly dipslip extension in their central sections to oblique slip and strike slip at either end where they merge with the pdz. These styles of faulting merge at greater depths into a single fault. In terms of geometry and basin fill, it is similar to the tekirdag basin in the eastern marmara sea okay et al. Basement tectonics and origin of the sabine uplift lowed the pennsylvanianpermian ouachita orogenic thrust faulting fig. Active faults and evolving strikeslip basins in the marmara. Scaled, physical sandbox modelling has been used to simulate the progressive deformation of segmented strikeslip fault systems at both releasing pullapart basins and restraining oversteps popup structures developed in a weak sedimentary cover above rigid basement. This geometric relationship between dipslip and strikeslip faulting requires synchronous movement and suggests that displacement on both sets has occurred in response to a common cause.
1193 1558 1311 1065 1472 43 536 1223 584 121 53 697 1410 738 527 343 1421 629 1314 1307 157 1181 1161 1280 937 756 871 48 535 1017 436 617 935 973