Hydration in the Crust and Upper Mantle Near the Extinct Spreading Ridge in the Eastern Sub‐Basin, South China Sea
Year: 2025
Type: article
Abstract: During the final stages of seafloor spreading in the East Sub‐basin of the South China Sea, spreading transitioned from slow to ultraslow before cessation. However, post‐spreading volcanism has obscured the original fabric along or near the extinct spreading ridge (ESR). We present a detailed V P / V S model along a profile perpendicular to the ESR, constructed using independent tomography of P ‐ and S ‐wave data. This model provides critical constraints on the crustal lithology and tectonic evolution of the ESR. Our results show significant thinning of the crust (∼3.3–4.3 km) near the ESR. Within the thin crustal regions, anomalously elevated V P / V S ratios (>1.9) may indicate tectonic uplift of serpentinites. These observations indicate a substantial reduction in magma supply during the terminal phases of spreading, resulting in a near absence of lower crust. During this period, tectonic extension dominated, and crustal fracturing facilitated seawater infiltration into the upper mantle, promoting serpentinite formation.
Source: Geophysical Research Letters
DOI: 10.1029/2025gl115670
Authors: Hui Jiang, Haibo Huang, Enyuan He, Jian Guo, Xuelin Qiu
Language: English
Subfield: Geology
Field: Earth and Planetary Sciences
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,190
Funders: Yuhan, National Natural Science Foundation of China, Youth Innovation Promotion Association of the Chinese Academy of Sciences, Nutrition Obesity Research Center, University of North Carolina, South China Sea Institute of Oceanology, Chinese Academy of Sciences, Youth Innovation Promotion Association
OpenAlex ID: W4413377212