Is the North Altyn fault part of a strike-slip duplex along the Altyn Tagh fault system?

Geology ◽  
2000 ◽  
Vol 28 (3) ◽  
pp. 255 ◽  
Author(s):  
Eric Cowgill ◽  
An Yin ◽  
Wang Xiao Feng ◽  
Zhang Qing
Keyword(s):  
Strike Slip ◽  
Fault System ◽  
Altyn Tagh Fault ◽  
The North ◽  
Altyn Tagh

Is the North Altyn fault part of a strike-slip duplex along the Altyn Tagh fault system?

Geology ◽  
2000 ◽  
Vol 28 (3) ◽  
pp. 255-258 ◽  
Author(s):  
Eric Cowgill ◽  
An Yin ◽  
Wang Xiao Feng ◽  
Zhang Qing
Keyword(s):  
Strike Slip ◽  
Fault System ◽  
Altyn Tagh Fault ◽  
The North ◽  
Altyn Tagh

scholarly journals Development and Interplay of Two Orthogonal Fault Systems in the NW Qaidam Basin, Northern Tibetan Plateau

2021 ◽  
Vol 9 ◽  
Author(s):  
Kai Huang ◽  
Lei Wu ◽  
Haifeng Zhao ◽  
Junyong Zhang ◽  
Yongshu Zhang ◽  
...  
Keyword(s):  
Qaidam Basin ◽  
Fault System ◽  
Altyn Tagh Fault ◽  
Seismic Reflection Data ◽  
The North ◽  
Reflection Data ◽  
Detailed Structural Analysis ◽  
Northern Tibetan Plateau ◽  
Altyn Tagh ◽  
Thrust Belts

How fold and thrust belts (FTBs) evolve over time and space in a transpressional regime remains poorly understood. Based on high-resolution 3D seismic reflection data and remote sensing images, we herein present a detailed structural analysis of the Cenozoic faults in the NW margin of the Qaidam Basin that is bounded to the north by the left-reverse Altyn Tagh fault system. Two sets of orthogonal, basement-involved faults with contrasting geometries, kinematics, and temporal development are identified. One set consists of generally E-W-striking, N-dipping, reverse faults with a component of sinistral shear. They are parallel or subparallel to the Altyn Tagh fault system, led to southward tilting of the basement, and formed a local unconformity between the middle Miocene Shangyoushashan formation and underlying strata. They developed in an out-of-sequence order, and were mostly active during 43.8–15.3 Ma but in relatively tectonic quiescence with limited weak reactivation since then. The second set is mainly composed of the NNW-striking reverse faults with dextral shear components. They are approximately perpendicular to the Altyn Tagh fault system, and intensively active since ∼15.3 Ma, much later than the initiation of the E-W-striking faults. Together with published results, we ascribe the development of these two sets of orthogonal faults as the transition from transpression to left lateral slip on the central segment of the Altyn Tagh fault system. The two fault sets interplayed with each other in two ways: 1) the older E-W-striking faults were offset by younger NNW-striking faults, and 2) the younger NNW-striking faults curved to link with the preexisting E-W-striking faults. Our findings reveal that transpressional-dominated FTBs evolve in a more complicated way than the contractional-dominated ones, and more site-based case studies are needed to reveal the underlying primary principles.

Inversion of regional surface-wave spectra for source parameters of aftershocks from the 1992 Petrolia earthquake sequence

1995 ◽  
Vol 85 (3) ◽  
pp. 705-715
Author(s):  
Mark Andrew Tinker ◽  
Susan L. Beck
Keyword(s):  
Surface Wave ◽  
Focal Mechanism ◽  
Source Parameters ◽  
Strike Slip ◽  
Earthquake Sequence ◽  
Fault System ◽  
Accretionary Wedge ◽  
Wave Spectra ◽  
The North ◽  
Gorda Plate

Abstract Regional distance surface waves are used to study the source parameters for moderate-size aftershocks of the 25 April 1992 Petrolia earthquake sequence. The Cascadia subduction zone had been relatively seismically inactive until the onset of the mainshock (Ms = 7.1). This underthrusting event establishes that the southern end of the North America-Gorda plate boundary is seismogenic. It was followed by two separate and distinct large aftershocks (Ms = 6.6 for both) occurring at 07:41 and 11:41 on 26 April, as well as thousands of other small aftershocks. Many of the aftershocks following the second large aftershock had magnitudes in the range of 4.0 to 5.5. Using intermediate-period surface-wave spectra, we estimate focal mechanisms and depths for one foreshock and six of the larger aftershocks (Md = 4.0 to 5.5). These seven events can be separated into two groups based on temporal, spatial, and principal stress orientation characteristics. Within two days of the mainshock, four aftershocks (Md = 4 to 5) occurred within 4 hr of each other that were located offshore and along the Mendocino fault. These four aftershocks comprise one group. They are shallow, thrust events with northeast-trending P axes. We interpret these aftershocks to represent internal compression within the North American accretionary prism as a result of Gorda plate subduction. The other three events compose the second group. The shallow, strike-slip mechanism determined for the 8 March foreshock (Md = 5.3) may reflect the right-lateral strike-slip motion associated with the interaction between the northern terminus of the San Andreas fault system and the eastern terminus of the Mendocino fault. The 10 May aftershock (Md = 4.1), located on the coast and north of the Mendocino triple junction, has a thrust fault focal mechanism. This event is shallow and probably occurred within the accretionary wedge on an imbricate thrust. A normal fault focal mechanism is obtained for the 5 June aftershock (Md = 4.8), located offshore and just north of the Mendocino fault. This event exhibits a large component of normal motion, representing internal failure within a rebounding accretionary wedge. These two aftershocks and the foreshock have dissimilar locations in space and time, but they do share a north-northwest oriented P axis.

scholarly journals Propagation of a strike-slip plate boundary within an extensional environment: the westward propagation of the North Anatolian Fault

2016 ◽  
Vol 53 (11) ◽  
pp. 1416-1439 ◽  
Author(s):  
Xavier Le Pichon ◽  
A.M. Celâl Şengör ◽  
Julia Kende ◽  
Caner İmren ◽  
Pierre Henry ◽  
...  
Keyword(s):  
Plate Boundary ◽  
Strike Slip ◽  
Fault System ◽  
Plate Boundaries ◽  
Sea Of Marmara ◽  
The North ◽  
Gulf Of Corinth ◽  
Northern Border ◽  
North Aegean ◽  
Narrow Plate

We document the establishment of the Aegea–Anatolia/Eurasia plate boundary in Pliocene–Pleistocene time. Before 2 Ma, no localized plate boundary existed north of the Aegean portion of the Anatolia plate and the shear produced by the motion of Anatolia–Aegea with respect to Eurasia was distributed over the whole width of the Aegean – West Anatolian western portion. In 4.5 Ma, a shear zone comparable to the Gulf of Corinth was formed in the present Sea of Marmara. The initial extensional basins were cut by the strike-slip Main Marmara Fault system after 2.5 Ma. Shortly after, the plate boundary migrated west of the Sea of Marmara along the northern border of Aegea from the North Aegean Trough, to the Gulf of Corinth area and to the Kefalonia Fault. There, it finally linked with the northern tip of the Aegean subduction zone, completing the system of plate boundaries delimiting the Anatolia–Aegea plate. We have related the change in the distribution of shear from Miocene to Pliocene to the formation of a relatively undeforming Aegea block in Pliocene that forced the shear to be distributed over a narrow plate boundary to the north of it. We attribute the formation of this block to the northeastward progression of the oceanic Ionian slab. We propose that the slab cuts the overlying lithosphere from asthenospheric sources and induces a shortening environment over it.

Crustal deformation along the Altyn Tagh fault system, western China, from GPS

2001 ◽  
Vol 106 (B12) ◽  
pp. 30607-30621 ◽  
Author(s):  
Zheng-Kang Shen ◽  
Min Wang ◽  
Yanxing Li ◽  
David D. Jackson ◽  
An Yin ◽  
...  
Keyword(s):  
Crustal Deformation ◽  
Western China ◽  
Fault System ◽  
Altyn Tagh Fault ◽  
Altyn Tagh

Geological mapping of the 1985 Chinese—British Tibetan (Xizang—Qinghai) Plateau Geotraverse route

1988 ◽  
Vol 327 (1594) ◽  
pp. 287-305 ◽  
Keyword(s):  
Strike Slip ◽  
Geological Mapping ◽  
Strike Slip Fault ◽  
Fault System ◽  
Late Triassic ◽  
Clastic Rocks ◽  
The North ◽  
Opposite Sequence ◽  
Geological Map ◽  
Qiangtang Terrane

The 1:500,000 coloured geological map of the traverse route combines observations from the Geotraverse, previous mapping, and interpretation of orbital images. The position of all localities visited by Geotraverse participants and basic geological data collected by them along the traverse route are shown on a set of maps originally drawn at 1:100,000 scale, reproduced on microfiche for this publication. More detailed mapping, beyond a single line of section, was achieved in five separate areas. The relationships between major rock units in these areas, and their significance, are outlined in this paper. Near Gyanco, (Lhasa Terrane) an ophiolite nappe, apparently connected with outcrops of ophiolites in the Banggong Suture about 100 km to the north, was under thrust by a discontinuous slice of Carboniferous—Permian clastic rocks and limestone, contrary to a previous report of the opposite sequence. At Amdo, a compressional left-lateral strike-slip fault zone has modified relationships along the Banggong Suture. Near Wuli, (northern Qiangtang Terrane) limited truncation of Triassic strata at the angular unconformity below Eocene redbeds demonstrates that most of the folding here is of Tertiary age. The map of the nearby Erdaogou region displays strong fold and thrust-shortening of the Eocene redbeds, evidence of significant crustal shortening after the India- Asia collision began. In the Xidatan-Kunlun Pass area, blocks of contrasting Permo—Triassic rocks are separated by east-trending faults. Some of these faults are ductile and of late Triassic — early Jurassic age, others are brittle and part of the Neogene—Quaternary Kunlun leftlateral strike-slip fault system. Some more significant remaining problems that geological mapping might help to solve are discussed briefly, including evidence for a possible additional ophiolitic suture within the Qiangtang Terrane.

scholarly journals Active Strike-Slip Faulting and Systematic Deflection of Drainage Systems along the Altyn Tagh Fault, Northern Tibetan Plateau

2021 ◽  
Vol 13 (16) ◽  
pp. 3109
Author(s):  
Peng Chen ◽  
Bing Yan ◽  
Yuan Liu
Keyword(s):  
Tibetan Plateau ◽  
Large Scale ◽  
Regional Scale ◽  
Strike Slip ◽  
The Tibetan Plateau ◽  
Stream Channels ◽  
Altyn Tagh Fault ◽  
Drainage Systems ◽  
Northern Tibetan Plateau ◽  
Altyn Tagh

Systematic deflection of drainage systems along strike-slip faults is the combination of repeated faulting slipping and continuous headward erosion accumulated on the stream channels. The measurement and analysis of systematically deflected stream channels will enhance our understanding on the deformational behaviors of strike-slip faults and the relationship between topographic response and active strike-slip faulting. In this study, detailed interpretation and analysis of remote sensing images and DEM data were carried out along the Altyn Tagh Fault, one typical large-scale strike-slip fault in the northern Tibetan Plateau, and together with the statistical results of offset amounts of 153 stream channels, revealed that (i) the drainage systems have been systematically deflected and/or offset in sinistral along the active Altyn Tagh Fault; (ii) The offset amounts recorded by stream channels vary in the range of 7 m to 72 km, and indicate a positively related linear relationship between the upstream length L and the offset amount D, the channel with bedrock upstream generally has a better correlation between L and D than that of non-bedrock upstream; (iii) River capture and abandonment are commonly developed along the Altyn Tagh Fault, which probably disturbed the continuous accumulation of offset recorded on individual stream channel, suggesting that the real maximum cumulative displacement recorded by stream channels might be larger than 72 km (lower bound) along the Altyn Tagh Fault. Along with the cumulative displacements recorded by other regional-scale strike-slip faults in the Tibetan Plateau, these results demonstrate that the magnitude of tectonic extrusion along these first-order strike-slip faults after the collision of India–Asia plates might be limited.

scholarly journals Segmentation and termination of the surface rupture zone produced by the 1932 Ms 7.6 Changma earthquake: New insights into the slip partitioning of the eastern Altyn Tagh fault system

Lithosphere ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 19-39
Author(s):  
Jiaxin Du ◽  
Bihong Fu ◽  
Qiang Guo ◽  
Pilong Shi ◽  
Guoliang Xue ◽  
...  
Keyword(s):  
Slip Rate ◽  
Rupture Zone ◽  
Fault System ◽  
Surface Rupture ◽  
Altyn Tagh Fault ◽  
Slip Rates ◽  
Leading Role ◽  
Surface Rupture Zone ◽  
Altyn Tagh ◽  
Slip Partitioning

Abstract The 1932 Ms 7.6 earthquake struck the active Changma fault in the NE Tibetan Plateau, and produced a distinct surface rupture along the fault zone. However, the segmentation and termination of the surface rupture zone are still unclear. In this paper, the active tectonic analyses of multiple satellite images complemented by field investigations present the 120-km-long surface rupture zone, which can be divided into five discrete first-order segments, ranging from 14.4 to 39.56 km in length, linked by step-overs. Our results also indicate that the 1932 rupture zone could jump across step-overs 0.3–4.5 km long and 2.2–5.4 km wide in map view, but was terminated by a 6.3-km-wide restraining step-over at the eastern end. The left-lateral slip rates along the mid-eastern and easternmost segments of the Changma fault are 3.43 ± 0.5 mm/yr and 4.49 ± 0.5 mm/yr since 7–9 ka, respectively. The proposed tectonic models suggest that the slip rates on the Changma fault are similar to the slip rate on the eastern segment of the Altyn Tagh fault system near the junction point with the Changma fault. These results imply that the Changma fault plays a leading role in the slip partitioning of the easternmost segment of the Altyn Tagh fault system.

Sign in / Sign up

Export Citation Format

Share Document