Active and passive salt diapirs: a numerical study

IF 2.8 3区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS Geophysical Journal International Pub Date : 2024-08-14 DOI:10.1093/gji/ggae284
Yiren Gou, Mian Liu
{"title":"Active and passive salt diapirs: a numerical study","authors":"Yiren Gou, Mian Liu","doi":"10.1093/gji/ggae284","DOIUrl":null,"url":null,"abstract":"Summary Salt diapirs dominate the structure in many sedimentary basins and control the preservation and migration of hydrocarbon. The formation of salt diapirs generally falls into two endmember models: active (up-building) and passive (down-building) diapirism. In the active model, salt diapirs rise from salt buoyancy to pierce through the sedimentary overburden, whereas in the passive model, salt diapirs result from differential loading of sediments during deposition. These endmember models are mostly conceptual or kinematic, the mechanics of active and passive diapirism, and their relative roles and interactions in the formation of salt diapirs, remain uncertain. Here, we use two-dimensional high-resolution numerical models to investigate the primary factors and critical conditions for active and passive diapirism. Our results indicate that it is improper to use driving mechanisms to classify salt diapirs, because the buoyancy-driven active salt diapirism involves differential loading, while the passive diapirism requires salt buoyancy. The rise of salt diapirs is more sensitive to the effective viscosity of the overburden than to the salt viscosity. Stiff overburdens could prevent the rise of salt diapirs, but they could be pierced by salt diapirs if plastic yield of the overburden is allowed. During deposition, the coupled salt-sediment deformation, driven by both salt buoyancy and differential loading of sediments, can lead to various diapiric salt structures and minibasins. Regional tectonic stress generally promotes salt diapirism by enhancing strain weakening of salts and overburdens. We suggest that the classification of active and passive salt diapirism is an oversimplification in most cases. We propose a general model of the formation of salt diapirs that usually begins with dome initiation driven by salt buoyancy, followed by syndepositional down-building controlled by sedimentation and differential loading, and ends with canopy formation when sedimentation stops.","PeriodicalId":12519,"journal":{"name":"Geophysical Journal International","volume":"43 1","pages":""},"PeriodicalIF":2.8000,"publicationDate":"2024-08-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geophysical Journal International","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1093/gji/ggae284","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

Summary Salt diapirs dominate the structure in many sedimentary basins and control the preservation and migration of hydrocarbon. The formation of salt diapirs generally falls into two endmember models: active (up-building) and passive (down-building) diapirism. In the active model, salt diapirs rise from salt buoyancy to pierce through the sedimentary overburden, whereas in the passive model, salt diapirs result from differential loading of sediments during deposition. These endmember models are mostly conceptual or kinematic, the mechanics of active and passive diapirism, and their relative roles and interactions in the formation of salt diapirs, remain uncertain. Here, we use two-dimensional high-resolution numerical models to investigate the primary factors and critical conditions for active and passive diapirism. Our results indicate that it is improper to use driving mechanisms to classify salt diapirs, because the buoyancy-driven active salt diapirism involves differential loading, while the passive diapirism requires salt buoyancy. The rise of salt diapirs is more sensitive to the effective viscosity of the overburden than to the salt viscosity. Stiff overburdens could prevent the rise of salt diapirs, but they could be pierced by salt diapirs if plastic yield of the overburden is allowed. During deposition, the coupled salt-sediment deformation, driven by both salt buoyancy and differential loading of sediments, can lead to various diapiric salt structures and minibasins. Regional tectonic stress generally promotes salt diapirism by enhancing strain weakening of salts and overburdens. We suggest that the classification of active and passive salt diapirism is an oversimplification in most cases. We propose a general model of the formation of salt diapirs that usually begins with dome initiation driven by salt buoyancy, followed by syndepositional down-building controlled by sedimentation and differential loading, and ends with canopy formation when sedimentation stops.
查看原文
分享 分享
微信好友 朋友圈 QQ好友 复制链接
本刊更多论文
主动和被动盐沼泽:数值研究
摘要 盐沼是许多沉积盆地的主要结构,控制着碳氢化合物的保存和迁移。盐陡崖的形成一般分为两种末端模式:主动(向上形成)和被动(向下形成)陡崖模式。在主动模式中,盐堰塞湖因盐浮力而上升,穿透沉积覆盖层;而在被动模式中,盐堰塞湖则是沉积物在沉积过程中受到不同荷载而形成的。这些末段模型大多是概念性的或运动学的,主动和被动泻流的力学原理以及它们在盐堰塞湖形成过程中的相对作用和相互作用仍不确定。在此,我们使用二维高分辨率数值模型来研究主动和被动泻流的主要因素和关键条件。我们的研究结果表明,用驱动机制来划分盐气堰塞湖是不恰当的,因为浮力驱动的主动盐气堰塞湖涉及不同的负载,而被动堰塞湖则需要盐的浮力。与盐的粘度相比,盐层的上升对覆盖层的有效粘度更为敏感。坚硬的覆盖层可以阻止盐池的上升,但如果覆盖层允许塑性屈服,盐池就会穿透覆盖层。在沉积过程中,由盐浮力和沉积物不同荷载驱动的盐-沉积物耦合变形可导致各种斜坡盐结构和小盆地。区域构造应力通常会通过增强盐和覆盖层的应变弱化来促进盐层断陷。我们认为,在大多数情况下,主动和被动盐层断裂的分类过于简单。我们提出了一个关于盐沼泽形成的一般模型,它通常由盐浮力驱动的穹隆开始,然后是由沉积和差异荷载控制的联合沉积向下建造,最后在沉积停止时形成冠层。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 去求助
来源期刊
Geophysical Journal International
Geophysical Journal International 地学-地球化学与地球物理
CiteScore
5.40
自引率
10.70%
发文量
436
审稿时长
3.3 months
期刊介绍: Geophysical Journal International publishes top quality research papers, express letters, invited review papers and book reviews on all aspects of theoretical, computational, applied and observational geophysics.
期刊最新文献
Modelling of non-linear elastic constitutive relationship and numerical simulation of rocks based on the Preisach-Mayergoyz space model Marginal stability analyses for thermochemical convection and its implications for the dynamics of continental lithosphere and core-mantle boundary regions Deep neural helmholtz operators for 3D elastic wave propagation and inversion Event locations: Speeding up grid searches using quadratic interpolation Internal deformation of the North Andean Sliver in Ecuador-southern Colombia observed by InSAR
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
0
微信
客服QQ
Book学术公众号 扫码关注我们
反馈
×
意见反馈
请填写您的意见或建议
请填写您的手机或邮箱
已复制链接
已复制链接
快去分享给好友吧!
我知道了
×
扫码分享
扫码分享
Book学术官方微信
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术
文献互助 智能选刊 最新文献 互助须知 联系我们:info@booksci.cn
Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。
Copyright © 2023 Book学术 All rights reserved.
ghs 京公网安备 11010802042870号 京ICP备2023020795号-1