New paleomagnetic studies of Cretaceous and Miocene rocks from Jinggu, western Yunnan, China: Evidence for internal deformation of the Lanping–Simao Terrane

Gao, Liang; Yang, Zhenyu; Tong, Yabo; Wang, Heng; An, Chunzhi

doi:10.1016/j.jog.2015.06.004

Cited by 27 publications

(32 citation statements)

References 86 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Other studies considered rotation variability to represent simply data scatter compared to megablock rigid rotations (Funahara et al, ; Huang & Opdyke, , ; Li, Advokaat, et al, ; Li et al, ; Otofuji et al, ; Tong et al, ). Yoshioka et al (), Kondo et al (), and Gao et al () proposed that local rotations are due to oroclinal bending of already formed thrust‐fold structures, a pattern that is not substantiated by our data.…”

Section: Discussion: Crust Fragmentation Within the Simao And Lanpingcontrasting

confidence: 81%

“…The Chuandian domain yields a rather clear pattern of 15–20° CW rotations for Cretaceous‐Oligocene red beds (Funahara et al, ; Gao et al, ; Li et al, , ; Otofuji et al, ; Tong et al, ; Wang, Yang, et al, ; Yang, Sun, et al, ; Yoshioka et al, ; Zhu et al, ). Jurassic‐Oligocene red beds from the Baoshan, Lanping, and northern Simao domains provide highly variable CW rotations, in few cases exceeding 90° (Chen et al, ; Funahara et al, ; Gao et al, ; Huang & Opdyke, , ; Kondo et al, ; Li, Yang, et al, ; Li et al, ; Sato et al, , , ; Tanaka et al, ; Tong et al, , ; Yang, Yin, et al, ; Yang, Sun, et al, ). In the Tengchong domain, both CW and counterclockwise (CCW) rotations have been documented (Kornfeld et al, , ).…”

Section: Geologic Settingmentioning

confidence: 99%

“…Although the microplate/megablock model prevailed in the paleomagnetic literature on northern Indochina, some papers indeed recognized the possibility of “internal” block deformation and local rotations, due to oroclinal bending of fold axes (Gao et al, ; Kondo et al, ; Yoshioka et al, ), or small blocks decoupled by an array of strike‐slip faults according to the “domino” model by McKenzie and Jackson () (Otofuji et al, ; Tanaka et al, ; Tsuchiyama et al, ; Wang et al, ). It is worth noting that Funahara et al (), Huang and Opdyke (), Sato et al (), and Tanaka et al () documented in the Lanping domain a few sites carrying a pretilting magnetization (primary magnetization as inferred by dual magnetic polarities in two cases) that implied little if any rotation (Figure ).…”

Section: Geologic Settingmentioning

confidence: 99%

See 2 more Smart Citations

Paleomagnetic Evidence for 25–15 Ma Crust Fragmentation of North Indochina (23–26°N): Consequence of Collision With Greater India NE Corner?

Speranza

Pellegrino

Zhang

et al. 2019

Geochem Geophys Geosyst

View full text Add to dashboard Cite

The Cenozoic deformation of SE Asia is classically related to India‐Asia collision and Tibet Plateau rise, supposedly resulting in the southeastward drift of lithospheric blocks bounded by strike‐slip faults with displacements in the order of 1,000 km. Here we report on the paleomagnetism of 44 Triassic‐Cretaceous red bed sites from the northern Simao, Chuandian, and Lanping “blocks,” along both sides of the Ailao Shan‐Red River shear zone (north Indochina). In the Simao domain, remagnetization predates folding and subsequent 48–70° clockwise rotation of three 2–5 km wide subblocks separated by two unrotated blocks. A primary magnetization component from the Lanping domain center suggests variably clockwise rotated (up to 95° ± 24°) sites, interrupted by a 2–6 km wide block that is rotated counterclockwise by 27° ± 6°. Thus, the Lanping and Simao “blocks” are far from being rigid, being made of a mosaic of independently deforming subblocks, whose kinematics and association with documented tectonics are speculative. It is unclear whether both folding and widespread remagnetization were synchronous or diachronous across north Indochina, but (considering previously published results) strike‐slip activity along major shear zones, remagnetization, rotations, and crustal shortening overlapped within the 32–15 Ma time window, thus were likely genetically related. As opposed to previous models, we suggest that in early to mid‐Cenozoic times, north Indochina was under the influence of oblique Neo‐Tethys subduction. Collision between the NE corner of Greater India and Indochina at ~30 Ma yielded ENE‐WSW shortening and strike‐slip reactivation of preexisting faults, in turn fragmenting the crust into small, independently rotating, blocks.

show abstract

Section: Discussion: Crust Fragmentation Within the Simao And Lanpingcontrasting

confidence: 81%

Section: Geologic Settingmentioning

confidence: 99%

Section: Geologic Settingmentioning

confidence: 99%

See 1 more Smart Citation

Paleomagnetic Evidence for 25–15 Ma Crust Fragmentation of North Indochina (23–26°N): Consequence of Collision With Greater India NE Corner?

Speranza

Pellegrino

Zhang

et al. 2019

Geochem Geophys Geosyst

View full text Add to dashboard Cite

show abstract

“…The paleolatitude 19.9° ± 3.6°N for the Zhenyuan deposit and 16.2° ± 2.9°N for the Chang'an deposit are generally comparable to the value of 19.0° ± 3.6°N for the ca. 20.0 Ma strata at Jinggu in Indochina block (Figures a and d; Chen et al, ; Cogné et al, ; Gao et al, ; Li et al, ). However, the paleolatitudes of these deposits are strikingly different from those obtained from strata of ca.…”

Section: Discussionmentioning

confidence: 98%

“…Previous paleomagnetic studies from ca. 130 to 40 Ma strata of the Indochina block consistently showed large‐scale southward displacement caused by the ARSZ shearing (e.g., Gao et al, ; Kondo et al, ; Li et al, ; Tong et al, ). The average displacement is 7.5°, approximating a 1,000 km left‐lateral offset (Figure b and Table S1).…”

Section: Discussionmentioning

confidence: 99%

Relationship Between Orogenic Gold Mineralization and Crustal Shearing Along Ailaoshan‐Red River Belt, Southeastern Tibetan Plateau: New Constraint From Paleomagnetism

Gao

Wang

Deng

et al. 2018

Geochem Geophys Geosyst

Self Cite

View full text Add to dashboard Cite

A new perspective on the relationship between orogenic gold mineralization and crustal shearing is presented in this case study on the gold deposits along Ailaoshan‐Red River shear zone (ARSZ), southeastern Tibetan Plateau. The sinistral ductile shearing along the zone occurred from ca. 31 to 17 Ma resulting in a displacement of ~1,000 km. A series of orogenic gold deposits, represented by the Zhenyuan and Chang'an deposits, occur on western margin of the ARSZ. The timing of mineralization and its relationship to shearing continues to be debated despite extensive geological and geochemical studies. Here we try to clarify this issue by using paleomagnetism to constrain the paleolatitude of mineralized rocks. High temperature magnetization components were isolated from the mineralized rocks, and they record modification by ore‐forming fluid. Their magnetization yields a paleolatitude of 19.9° ± 3.6°N for the Zhenyuan deposit and 16.2° ± 2.9°N for the Chang'an deposit. The paleolatitudes from these deposits are similar to those of ca. 20 Ma strata (19.0° ± 3.6°N), deposited after the large‐scale shearing. By contrast, they differ significantly from the paleolatitude obtained from ca. 130 to 40 Ma strata (28.4° ± 1.1°N), which formed long before the onset of large‐scale shearing. These observations imply that the orogenic gold mineralization occurred after the main offset and associated ductile deformation of the ARSZ. Gold mineralization is thought to be related to ore‐forming fluids and metals derived from the subcrust, rather than from fluids released from shearing‐induced metamorphism of regional strata.

show abstract

Paleomagnetic Constraints From the Baoshan Area on the Deformation of the Qiangtang‐Sibumasu Terrane Around the Eastern Himalayan Syntaxis

Hinsbergen

Deng

et al. 2018

JGR Solid Earth

View full text Add to dashboard Cite

The Sibumasu Block in SE Asia represents the eastward continuation of the Qiangtang Block. Here we report a detailed rock magnetic and paleomagnetic study on the Middle Jurassic and Paleocene rocks from northern Sibumasu, to document the crustal deformation during the India‐Asia collision since the Paleocene and reconstruct the overall strike of the Qiangtang/Sibumasu elements before the India‐Asia collision. Although the fold test is inconclusive based solely on our data, a positive reversal test, a positive regional fold test with previous paleomagnetic results, and a detrital origin of hematite in the red beds as indicated by scanning electron microscopy suggest that the magnetizations obtained from the Jurassic and Paleocene rocks are most likely primary, showing an ~80° clockwise rotation since Paleocene. These results, together with previously published paleomagnetic data, suggest that the northern Sibumasu and northern Simao elements experienced a ~60–80° clockwise rotation since Paleocene. This large clockwise rotation is also consistent with the surface GPS velocity field and NE‐SW fault networks, suggesting a rotational motion of crustal material from southeastern Tibet during late Cenozoic. We infer that the large clockwise rotation is a sum of rotation in the Eocene to Middle Miocene time associated with Indochina extrusion and rotation after the Middle Miocene associated with the E‐W extension in central Tibet. This suggests that the eastward motion of Tibetan crustal material along the Xianshuihe‐Xiaojiang fault after Middle Miocene is transmitted to the southwest toward Myanmar. Jurassic and Cretaceous paleomagnetic results suggest that the Qiangtang/northern Sibumasu was originally a curved structure with an orientation of N60°W in Tibet and changes to N10°W in southern Sibumasu.

show abstract

New paleomagnetic studies of Cretaceous and Miocene rocks from Jinggu, western Yunnan, China: Evidence for internal deformation of the Lanping–Simao Terrane

Cited by 27 publications

References 86 publications

Paleomagnetic Evidence for 25–15 Ma Crust Fragmentation of North Indochina (23–26°N): Consequence of Collision With Greater India NE Corner?

Paleomagnetic Evidence for 25–15 Ma Crust Fragmentation of North Indochina (23–26°N): Consequence of Collision With Greater India NE Corner?

Relationship Between Orogenic Gold Mineralization and Crustal Shearing Along Ailaoshan‐Red River Belt, Southeastern Tibetan Plateau: New Constraint From Paleomagnetism

Paleomagnetic Constraints From the Baoshan Area on the Deformation of the Qiangtang‐Sibumasu Terrane Around the Eastern Himalayan Syntaxis

Contact Info

Product

Resources

About