THE TYPES AND ROLE OF STEPOVERS IN STRIKE-SLIP TECTONICS

1985 ◽  
pp. 35-44 ◽  
Author(s):  
ATILLA AYDIN ◽  
AMOS NUR
Keyword(s):  
Strike Slip

Role of Strike-slip Faulting in the Evolution of the Chumphon Basin, Gulf of Thailand

2019 ◽  
Author(s):  
Sarawute Chantraprasert ◽  
Jakkree Kongchum ◽  
Natapol Kuenphan
Keyword(s):  
Strike Slip ◽  
Gulf Of Thailand

scholarly journals Superposition of two kinematically distinct extensional phases in southern Death Valley: Implications for extensional tectonics

Geosphere ◽  
2021 ◽  
Author(s):  
Z.D. Fleming ◽  
T.L. Pavlis ◽  
S. Canalda
Keyword(s):  
Early Period ◽  
Rock Avalanche ◽  
Strike Slip ◽  
Death Valley ◽  
Normal Faults ◽  
Geologic Mapping ◽  
The North ◽  
Transcurrent Deformation ◽  
Two Phases

Geologic mapping in southern Death Valley, California, demonstrates Mesozoic contractional structures overprinted by two phases of Neogene extension and contemporaneous strike-slip deformation. The Mesozoic folding is most evident in the middle unit of the Noonday Formation, and these folds are cut by a complex array of Neogene faults. The oldest identified Neogene faults primarily displace Neoproterozoic units as young as the Johnnie Formation. However, in the northernmost portion of the map area, they displace rocks as young as the Stirling Quartzite. Such faults are seen in the northern Ibex Hills and con­sist of currently low- to moderate-angle, E-NE– dipping normal faults, which are folded about a SW-NE–trending axis. We interpret these low-angle faults as the product of an early, NE-SW extension related to kinematically similar deformation recognized to the south of the study area. The folding of the faults postdates at least some of the extension, indicating a component of syn-exten­sional shortening that is probably strike-slip related. Approximately EW-striking sinistral faults are mapped in the northern Saddlepeak Hills. However, these faults are kinematically incompatible with the folding of the low-angle faults, suggesting that folding is related to the younger, NW-SE extension seen in the Death Valley region. Other faults in the map area include NW- and NE-striking, high-angle normal faults that crosscut the currently low-angle faults. Also, a major N-S–striking, oblique-slip fault bounds the eastern flank of the Ibex Hills with slickenlines showing rakes of <30°, which together with the map pattern, suggests dextral-oblique movement along the east front of the range. The exact timing of the normal faulting in the map area is hampered by the lack of geochronology in the region. However, based on the map relationships, we find that the older extensional phase predates an angular unconformity between a volcanic and/or sedimentary succession assumed to be 12–14 Ma based on correlations to dated rocks in the Owlshead Mountains and overlying rock-avalanche deposits with associated sedimentary rocks that we correlate to deposits in the Amargosa Chaos to the north, dated at 11–10 Ma. The mechanism behind the folding of the northern Ibex Hills, including the low- angle faults, is not entirely clear. However, transcurrent systems have been proposed to explain extension-parallel folding in many extensional terranes, and the geometry of the Ibex Hills is consistent with these models. Collectively, the field data support an old hypothesis by Troxel et al. (1992) that an early period of SW-NE extension is prominent in the southern Death Valley region. The younger NW-SE extension has been well documented just to the north in the Black Mountains, but the potential role of this earlier extension is unknown given the complexity of the younger deformation. In any case, the recognition of earlier SW-NE extension in the up-dip position of the Black Mountains detachment system indicates important questions remain on how that system should be reconstructed. Collectively, our observations provide insight into the stratigraphy of the Ibex Pass basin and its relationship to the extensional history of the region. It also highlights the role of transcurrent deformation in an area that has transitioned from extension to transtension.

scholarly journals Classification of Zagros earthquakes based on focal mechanism

2021 ◽  
Vol 51 (3) ◽  
pp. 265-275
Author(s):  
Mehdi Nouri DELOUEI ◽  
Mohammad-Reza GHEITANCHI
Keyword(s):  
Focal Mechanism ◽  
Strike Slip ◽  
Focal Mechanisms ◽  
Nodal Plane ◽  
Iranian Plateau ◽  
Populated Region ◽  
Compression Type ◽  
Selection Of

The Zagros suture zone is seismically active region in Iranian plateau. This region is of high importance in terms of seismicity, since it is a vast and populated region and in recent years the earthquakes with high intensities have frequently occurred and have caused extensive destruction and heavy human loss. The study of the focal mechanism is very important in understanding the seismotectonic characteristics. Focal mechanisms of Zagros were collected over a period of 20 years and they were classified by FMC software. Seven groups were considered for the type of faulting and Zagros was divided into three zones. For each zone, the frequency percentage of each group of faults was determined. The most of faulting are of the reverse and compression type with the strike-slip component. Finally, the role of nodal plane selection in determining the type of faulting was discussed and it was found that the selection of each nodal plane in determining the type of faulting has the same result.

The role of strike-slip faulting in the history of the Hukawng Block and the Jade Mines Uplift, Myanmar

2019 ◽  
Vol 130 (2) ◽  
pp. 126-141 ◽  
Author(s):  
Michael F. Ridd ◽  
Michael J. Crow ◽  
Christopher K. Morley
Keyword(s):  
Strike Slip ◽  
History Of

The role of strike-slip tectonics in the Leinetal Graben, Lower Saxony

2010 ◽  
Vol 161 (4) ◽  
pp. 369-377 ◽  
Author(s):  
David C. Tanner ◽  
Bernd Leiss ◽  
Axel Vollbrecht
Keyword(s):  
Strike Slip ◽  
Lower Saxony

The role of strike-slip fault systems at plate boundaries

1986 ◽  
Vol 317 (1539) ◽  
pp. 13-29 ◽  
Keyword(s):  
Relative Velocity ◽  
Velocity Vector ◽  
Significant Proportion ◽  
Plate Boundary ◽  
Strike Slip ◽  
Plate Boundaries ◽  
Poor Understanding ◽  
The Common ◽  
Orogenic Belts

A new analysis shows that most (59 %) plate boundaries have a relative velocity vector that is markedly oblique (greater than 22°) to the boundary normal. A significant proportion (14% ) have vectors that are nearly ( ± 22°) parallel to the boundary. Accommodation of the oblique motion usually involves strike-slip faulting, but the kinematic role of these faults differs at divergent and convergent boundaries. Four main types of plate-boundary related strike-slip faults are distinguished: ridge transforms, boundary transforms, trench-linked strike-slip faults and indent-linked strike-slip faults. Discrimination of the four types should be possible in ancient orogenic belts, but is complicated by the common reactivation of the strike-slip zones in other roles. Plate-boundary related strike-slip faults form major lineaments at the present day. Ridge transforms have a low preservation potential in continents. Boundary transforms and indent-linked faults often re-use old lineaments, but trench-linked strike-slip faulting is an effective method of forming new lineaments in continental crust. Strike-slip faulting in general is less commonly recognized in ancient orogenic belts than its abundance in present plate-boundary orogens requires. This under-recognition results both from poor understanding of strike-slip kinematics and from deeper prejudices about the way in which orogenic belts form.

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