Continental Interior and Edge Breakup at Convergent Margins Induced by Subduction Direction Reversal: A Numerical Modeling Study Applied to the South China Sea Margin
Abstract
The dynamics of continental breakup at convergent margins has been described as the results of backarc opening caused by slab rollback or drag force induced by subduction direction reversal. Although the rollback hypothesis has been intensively studied, our understanding of the consequence of subduction direction reversal remains limited. Using thermo‐mechanical modeling based on constraints from the South China Sea (SCS) region, we investigate how subduction direction reversal controls the breakup of convergent margins. The numerical results show that two distinct breakup modes, namely, continental interior and edge breakup ("edge" refers to continent above the plate boundary interface), may develop depending on the "maturity" of the convergent margin and the age of the oceanic lithosphere. For a slab age of ~15 to ~45 Ma, increasing the duration of subduction promotes the continental interior breakup mode, where a large block of the continental material is separated from the overriding plate. In contrast, the continental edge breakup mode develops when the subduction is a short‐duration event, and in this mode, a wide zone of less continuous continental fragments and tearing of the subducted slab occur. These two modes are consistent with the interior (relic late Mesozoic arc) and edge (relic forearc) rifting characteristics in the western and eastern SCS margin, suggesting that variation in the northwest‐directed subduction duration of the Proto‐SCS might be a reason for the differential breakup locus along the strike of the SCS margin. Besides, a two‐segment trench associated with the northwest‐directed subduction is implied in the present‐day SCS region.
Additional Information
© 2020 American Geophysical Union. Issue Online: 30 October 2020; Version of Record online: 30 October 2020; Accepted manuscript online: 06 October 2020; Manuscript accepted: 29 September 2020; Manuscript revised: 24 September 2020; Manuscript received: 02 July 2020. This research was supported by the Guangdong NSF research team project (2017A030312002), the Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou) (GML2019ZD0205), the K. C. Wong Education Foundation (GJTD‐2018‐13), the Strategic Priority Research Program of the Chinese Academy of Science (XDA13010303), the Chinese Academy of Sciences (Y4SL021001, QYZDY‐SSWDQC005, 133244KYSB20180029, and ISEE2019ZR01), the NSFC project (41606073, 41890813, and 41576070), the IODP‐China Foundation, the OMG Visiting Fellowship (OMG18‐15), and the Hong Kong Research Grant Council Grants (Nos. 14313816 and 14304820). We thank Fabio Crameri, Marta Pérez‐Gussinyé, two anonymous reviewers, editor Laurent Jolivet, and associated editor Laurent Husson for their constructive comments that contributed to improving the manuscript. An earlier review by Guillaume Duclaux is also appreciated. Data Availability Statement: Data can be obtained from a repository (https://figshare.com/s/ed3174627a7090e9ad45).Attached Files
Published - 2020TC006409.pdf
Supplemental Material - tect21418-sup-0001-2020tc006409-si.docx
Files
Name | Size | Download all |
---|---|---|
md5:fccdef07e9a15ba954027bad3f3f934b
|
68.1 kB | Download |
md5:50eababf78a9b15be23f223085dea074
|
17.6 MB | Preview Download |
Additional details
- Eprint ID
- 105899
- Resolver ID
- CaltechAUTHORS:20201007-140342146
- Natural Science Foundation of Guangdong Province
- 2017A030312002
- Key Special Project for Introduced Talents Team of Southern Marine Science and Engineering Guangdong Laboratory
- GML2019ZD0205
- K. C. Wong Education Foundation
- GJTD‐2018‐13
- Chinese Academy of Sciences
- XDA13010303
- Chinese Academy of Sciences
- Y4SL021001
- Chinese Academy of Sciences
- QYZDY‐SSWDQC005
- Chinese Academy of Sciences
- 133244KYSB20180029
- Chinese Academy of Sciences
- ISEE2019ZR01
- National Natural Science Foundation of China
- 41606073
- National Natural Science Foundation of China
- 41890813
- National Natural Science Foundation of China
- 41576070
- IODP‐China Foundation
- OMG Visiting Fellowship
- OMG18‐15
- Hong Kong Research Grant Council
- 14313816
- Hong Kong Research Grant Council
- 14304820
- Created
-
2020-10-07Created from EPrint's datestamp field
- Updated
-
2023-10-20Created from EPrint's last_modified field
- Caltech groups
- Seismological Laboratory, Division of Geological and Planetary Sciences