Abstract
The Guaymas Basin spreading center, at 2000 m depth in the Gulf of California, is overlain by a thick sedimentary cover. Across the basin, localized temperature anomalies, with active methane venting and seep fauna exist in response to magma emplacement into sediments. These sites evolve over thousands of years as magma freezes into doleritic sills and the system cools. Although several cool sites resembling cold seeps have been characterized, the hydrothermally active stage of an off-axis site was lacking good examples. Here, we present a multidisciplinary characterization of Ringvent, an ~1 km wide circular mound where hydrothermal activity persists ~28 km northwest of the spreading center. Ringvent provides a new type of intermediate-stage hydrothermal system where off-axis hydrothermal activity has attenuated since its formation, but remains evident in thermal anomalies, hydrothermal biota coexisting with seep fauna, and porewater biogeochemical signatures indicative of hydrothermal circulation. Due to their broad potential distribution, small size and limited life span, such sites are hard to find and characterize, but they provide critical missing links to understand the complex evolution of hydrothermal systems.
Highlights
The Guaymas Basin in the Gulf of California is a young marginal seafloor spreading system where new igneous crust forms in an environment of rapid sedimentation[1,2]
Our results indicate that this site is evolving from active, sill-driven hydrothermalism – characterized by the emergence of hot, reducing fluids - towards a cooler phase of localized fluid circulation dominated by methane flow
Previous surveys concluded that carbon mobilization at off-axis sites in this region occurs predominantly as cold methane seepage and that off-axis hydrothermal flow has to be estimated with care considering the lifespan of sill induced systems[4]
Summary
The Guaymas Basin in the Gulf of California is a young marginal seafloor spreading system where new igneous crust forms in an environment of rapid sedimentation[1,2]. The identification of hydrothermalism at Ringvent required a sequence of observations at increasingly smaller spatial scales, beginning with deep-towed seafloor mapping that identified numerous sites of likely seafloor fluid flow and followed by site-specific coring, ROV mapping, and submersible sampling at Ringvent. Such hydrothermally active sites may be intrinsically hard to identify, given the expected short duration (
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
