Academic Journal
Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49 degrees 39 ' E)
| العنوان: | Three-dimensional seismic structure of the Dragon Flag oceanic core complex at the ultraslow spreading Southwest Indian Ridge (49 degrees 39 ' E) |
|---|---|
| المؤلفون: | Zhao, Minghui, Qiu, Xuelin, Li, Jiabiao, Sauter, Daniel, Ruan, Aiguo, Chen, John, Cannat, Mathilde, Singh, Satish, Zhang, Jiazheng, Wu, Zhenli, Niu, Xiongwei |
| المساهمون: | Zhao, MH (reprint author), Chinese Acad Sci, Key Lab Marginal Sea Geol, South China Sea Inst Oceanol, Guangzhou 510301, Guangdong, Peoples R China., Chinese Acad Sci, Key Lab Marginal Sea Geol, South China Sea Inst Oceanol, Guangzhou 510301, Guangdong, Peoples R China., State Ocean Adm, Inst Oceanog 2, Hangzhou 310012, Zhejiang, Peoples R China., CNRS, UMR 7516, Inst Phys Globe Strasbourg, Strasbourg, France., Peking Univ, Sch Earth & Space Sci, Beijing 100871, Peoples R China., Inst Phys Globe Paris, Lab Geosci Marine, Paris, France., Univ Chinese Acad Sci, Beijing, Peoples R China. |
| المصدر: | EI ; SCI |
| بيانات النشر: | geochemistry geophysics geosystems |
| سنة النشر: | 2013 |
| المجموعة: | Peking University Institutional Repository (PKU IR) / 北京大学机构知识库 |
| مصطلحات موضوعية: | ultraslow spreading ridge, 3-D seismic structure, SW Indian Ridge, oceanic core complex, detachment fault, MID-ATLANTIC RIDGE, UPPER CRUSTAL STRUCTURE, EAST PACIFIC RISE, II FRACTURE-ZONE, SEA-FLOOR, HYDROTHERMAL FIELD, THIN CRUST, TOMOGRAPHY, REFRACTION, ACCRETION |
| الوصف: | The Southwest Indian Ridge (SWIR) is an ultraslow spreading end-member of mid-ocean ridge system. We use air gun shooting data recorded by ocean bottom seismometers (OBS) and multibeam bathymetry to obtain a detailed three-dimensional (3-D) P wave tomographic model centered at 49 degrees 39'E near the active hydrothermal "Dragon Flag'' vent. Results are presented in the form of a 3-D seismic traveltime inversion over the center and both ends of a ridge segment. We show that the crustal thickness, defined as the depth to the 7 km/s isovelocity contour, decreases systematically from the center (similar to 7.0-8.0 km) toward the segment ends (similar to 3.0-4.0 km). This variation is dominantly controlled by thickness changes in the lower crustal layer. We interpret this variation as due to focusing of the magmatic activity at the segment center. The across-axis velocity model documents a strong asymmetrical structure involving oceanic detachment faulting. A locally corrugated oceanic core complex (Dragon Flag OCC) on the southern ridge flank is characterized by high shallow crustal velocities and a strong vertical velocity gradient. We infer that this OCC may be predominantly made of gabbros. We suggest that detachment faulting is a prominent process of slow spreading oceanic crust accretion even in magmatically robust ridge sections. Hydrothermal activity at the Dragon Flag vents is located next to the detachment fault termination. We infer that the detachment fault system provides a pathway for hydrothermal convection. ; Geochemistry & Geophysics ; SCI(E) ; EI ; 4 ; ARTICLE ; 10 ; 4544-4563 ; 14 |
| نوع الوثيقة: | journal/newspaper |
| اللغة: | English |
| تدمد: | 1525-2027 |
| Relation: | GEOCHEMISTRY GEOPHYSICS GEOSYSTEMS.2013,14,(10),4544-4563.; 809959; http://hdl.handle.net/20.500.11897/220117; WOS:000330531400038 |
| DOI: | 10.1002/ggge.20264 |
| الاتاحة: | https://hdl.handle.net/20.500.11897/220117 https://doi.org/10.1002/ggge.20264 |
| رقم الانضمام: | edsbas.C6553E43 |
| قاعدة البيانات: | BASE |
| تدمد: | 15252027 |
|---|---|
| DOI: | 10.1002/ggge.20264 |