Signature of off-axis hydrothermal sulfide mineralization at 23.19°S of Central Indian Ridge: Insights from mineralogy, geochemistry, geochronology and near-seabed AUV survey

IF 2.6 3区地球科学 Q2 GEOSCIENCES, MULTIDISCIPLINARY

Marine Geology Pub Date : 2025-02-13 DOI:10.1016/j.margeo.2025.107500

Koushick Sen , P. John Kurian , Parijat Roy , Sunil Vadakkepuliyambatta , Georgy Cherkashov , L. Surya Prakash , Katherine Kuksa , Vladislav Kuznetsov , Anna Firstova , Abhishek Tyagi , Deepak K. Agarwal , Fedor Maksimov

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引用次数: 0

Abstract

Seafloor hydrothermal systems and associated sulfide mineralization have been reported along all types of mid-oceanic spreading ridges, island arcs, and back-arc settings. This study reports the occurrence of a distal ridge (∼35 km off-axis) hydrothermal mineralization zone from the slow-spreading Central Indian Ridge (23.19°S) of the Indian Ocean. The hydrothermal precipitates were recovered during dredging operations and mainly comprised of massive sulfides, sulfide breccias, and their secondary oxidized alteration products. The mineralogical quantification of pyrites (significant Cu enrichment, a strong negative correlation with Fe), and bulk sulfide geochemistry (concentrations and ratio of Ba, Co, and Pb) hint at a possible mixed type of mafic-ultramafic host-rock influence in the formation of sulfides. The ²³⁰Th/U chronological estimations of pyrites from massive sulfide and sulfide breccia suggest a wide range of hydrothermal activity from 144 ± 11 to 52 ± 7 ka. The AUV-assisted near sea floor sub-bottom profiling (SBP) and High-resolution Interferometric Synthetic Aperture Sonar (HISAS) images suggest that the study area is covered by thin layers of sediments with occasional exposure of hard rock outcrops. The reporting mineralization site stands out to be the most distant and one of the chronologically oldest hydrothermal mineralization zones within the Indian Ocean. The study provides insights into the broader geological processes at off-axis locations concerning the hydrothermal mineralization at slow-spreading ridges and indicates the possibility that such undiscovered buried hydrothermal fields may exist located far from the present-day ridge axis.

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来源期刊

Marine Geology 地学-地球科学综合

CiteScore

6.10

自引率

6.90%

发文量

175

审稿时长

21.9 weeks

期刊介绍： Marine Geology is the premier international journal on marine geological processes in the broadest sense. We seek papers that are comprehensive, interdisciplinary and synthetic that will be lasting contributions to the field. Although most papers are based on regional studies, they must demonstrate new findings of international significance. We accept papers on subjects as diverse as seafloor hydrothermal systems, beach dynamics, early diagenesis, microbiological studies in sediments, palaeoclimate studies and geophysical studies of the seabed. We encourage papers that address emerging new fields, for example the influence of anthropogenic processes on coastal/marine geology and coastal/marine geoarchaeology. We insist that the papers are concerned with the marine realm and that they deal with geology: with rocks, sediments, and physical and chemical processes affecting them. Papers should address scientific hypotheses: highly descriptive data compilations or papers that deal only with marine management and risk assessment should be submitted to other journals. Papers on laboratory or modelling studies must demonstrate direct relevance to marine processes or deposits. The primary criteria for acceptance of papers is that the science is of high quality, novel, significant, and of broad international interest.