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By harnessing both hypothetical, synthetic basin and gas hydrate (GH) system models and real‐world models of well‐studied salt diapir‐associated GH sites at Green Canyon (Gulf of Mexico) and Blake Ridge (U.S. Atlantic coast), we propose and demonstrate salt movement (and in particular, diapirism) to be a new mechanism for the recycling of marine GH. At Green Canyon, for example, we show that by considering this newly proposed diapir‐driven recycling mechanism in conjunction with previously proposed lithological control on sandy‐reservoir‐hosted hydrate at the base of the GH stability zone (BGHSZ; ∼bottom‐simulating reflector, BSR), modeled GH saturations match drilling data. Overall, salt diapir movement‐induced GH recycling provides a temperature‐driven mechanism by which GH saturations at the BGHSZ may reach >90 vol. % and by which GH volumes near and free gas volumes beneath the BGHSZ may be increased significantly through time. Interestingly, comparison of salt diapir‐driven recycling and sediment burial‐driven recycling scenarios suggests notably higher rates of recycling via diapir‐driven versus burial‐driven processes. Our results suggest that GH and associated free gas accumulations above salt diapir crests represent particularly attractive targets for unconventional and conventional hydrocarbon resource exploration and for scientific and academic drilling expeditions aimed at exploiting GH systems. Salt basins containing GH systems—including passive margin basins of the Gulf of Mexico, southeastern Brazil, and southwestern Africa—are therefore compelling localities for studying salt‐driven GH recycling and for salt diapir‐associated natural gas exploration. Plain Language Summary: Gas hydrates (GHs) are ice‐like solids widely distributed in permafrost settings and marine sediments of continental margins. Hydrate deposits contain vast amounts of carbon, mostly in the form of entrapped methane, and are therefore critical components of the global carbon cycle. High‐saturation GH accumulations are attractive as potentially extractable energy resources, and the processes resulting in concentrated hydrate deposits are therefore of particular scientific and economic interest. Here, we explore GH recycling, a process by which hydrates pushed below their pressure‐ and temperature‐defined stability zone destabilizes and releases buoyant gas that may be reincorporated into the upward‐shifted zone of hydrate stability, leading to increasingly elevated hydrate saturations. Using computational basin modeling and two‐dimensional forward modeling of both theoretical and real‐world GH systems, we present a new mechanism for GH recycling: the ascent of salt diapirs. Key Points: We demonstrate salt diapir movement and associated thermal changes to be a mechanism for gas hydrate recyclingHydrate at the base of hydrate stability can reach saturations >90 vol. % and trap large free gas accumulations via diapir‐driven recyclingDiapir‐driven recycling helps explain Green Canyon hydrate saturations and implies that salt basins with hydrate are attractive for exploration [ABSTRACT FROM AUTHOR] |
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