{"title":"Evidence for off-ridge thermal interaction along the Carlsberg and Central Indian ridges and its tectonic significance","authors":"K. S. Sreenidhi, K. M. Sreejith, M. Radhakrishna","doi":"10.1007/s11001-024-09547-2","DOIUrl":null,"url":null,"abstract":"<p>Seafloor spreading along the Carlsberg and Central Indian ridges has steered the tectonic evolution of the western Indian Ocean. These spreading ridges display variations in spreading rate, segmentation, and morphological characteristics, providing clues to the long-term evolution of the oceanic lithosphere in this region. To assess the influence of two notable off-axis thermal sources, the Réunion plume and the Indian Ocean Diffuse Boundary Zone, on factors such as rigidity and seafloor subsidence along these ridges, we computed the effective elastic thickness (Te), residual geoid-age slopes, and residual depth anomalies (RDA) of the region using gravity and geoid data. The results reveal a weaker lithosphere at the northern Central Indian Ridge (Te: ~ 8.5–8.9 km) compared to the neighboring segments of the southern Central Indian Ridge (Te: ~ 10.5–12.7 km) and the Carlsberg Ridge (Te: ~ 10.5–14.7 km). Residual geoid and RDA variations suggest asymmetric seafloor spreading and subsidence along the entire ridge system. The asymmetric subsidence across the Central Indian Ridge is largely due to upper mantle contamination from the Réunion plume, while across the Carlsberg Ridge, it may be linked to its complex tectonic history. The rigidity and seafloor spreading patterns along the northern Central Indian Ridge are notably affected by thermal perturbations from the regional heat flow anomaly of the ongoing diffuse deformation zone. Moreover, the Te and segmentation patterns roughly correlate along the ridge system, suggesting a causal relationship between the two or the presence of underlying factors such as regional thermal structure influencing both.</p>","PeriodicalId":49882,"journal":{"name":"Marine Geophysical Research","volume":null,"pages":null},"PeriodicalIF":1.6000,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Marine Geophysical Research","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1007/s11001-024-09547-2","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0
Abstract
Seafloor spreading along the Carlsberg and Central Indian ridges has steered the tectonic evolution of the western Indian Ocean. These spreading ridges display variations in spreading rate, segmentation, and morphological characteristics, providing clues to the long-term evolution of the oceanic lithosphere in this region. To assess the influence of two notable off-axis thermal sources, the Réunion plume and the Indian Ocean Diffuse Boundary Zone, on factors such as rigidity and seafloor subsidence along these ridges, we computed the effective elastic thickness (Te), residual geoid-age slopes, and residual depth anomalies (RDA) of the region using gravity and geoid data. The results reveal a weaker lithosphere at the northern Central Indian Ridge (Te: ~ 8.5–8.9 km) compared to the neighboring segments of the southern Central Indian Ridge (Te: ~ 10.5–12.7 km) and the Carlsberg Ridge (Te: ~ 10.5–14.7 km). Residual geoid and RDA variations suggest asymmetric seafloor spreading and subsidence along the entire ridge system. The asymmetric subsidence across the Central Indian Ridge is largely due to upper mantle contamination from the Réunion plume, while across the Carlsberg Ridge, it may be linked to its complex tectonic history. The rigidity and seafloor spreading patterns along the northern Central Indian Ridge are notably affected by thermal perturbations from the regional heat flow anomaly of the ongoing diffuse deformation zone. Moreover, the Te and segmentation patterns roughly correlate along the ridge system, suggesting a causal relationship between the two or the presence of underlying factors such as regional thermal structure influencing both.
期刊介绍:
Well-established international journal presenting marine geophysical experiments on the geology of continental margins, deep ocean basins and the global mid-ocean ridge system. The journal publishes the state-of-the-art in marine geophysical research including innovative geophysical data analysis, new deep sea floor imaging techniques and tools for measuring rock and sediment properties.
Marine Geophysical Research reaches a large and growing community of readers worldwide. Rooted on early international interests in researching the global mid-ocean ridge system, its focus has expanded to include studies of continental margin tectonics, sediment deposition processes and resulting geohazards as well as their structure and stratigraphic record. The editors of MGR predict a rising rate of advances and development in this sphere in coming years, reflecting the diversity and complexity of marine geological processes.