气候变化领域集成服务门户(CCPortal): Fluid Accumulation, Migration and Anaerobic Oxidation of Methane Along a Major Splay Fault at the Hikurangi Subduction Margin (New Zealand): A Magnetic Approach

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DOI	10.1029/2020JB020671
	Fluid Accumulation, Migration and Anaerobic Oxidation of Methane Along a Major Splay Fault at the Hikurangi Subduction Margin (New Zealand): A Magnetic Approach
	Greve A.; Kars M.; Dekkers M.J.
发表日期	2021
ISSN	21699313
卷号	126 期号:2
英文摘要	Understanding the locus of fluid flow along thrust and splay faults is important to understand the hydraulic properties of accretionary systems and fault mechanics. Here, we use rock magnetic techniques in combination with backscattered electron imaging to depict the locus of enhanced magnetic mineral alteration within the Pāpaku fault, an active splay fault of the subduction interface at the northern Hikurangi Margin. The Pāpaku fault was cored at Site U1518 during Expedition 375 of the International Ocean Discovery Program and we report room temperature magnetic parameters, complemented by first-order reversal and thermomagnetic curves in the depth interval 250–400 m below seafloor (mbsf). The ∼60-m wide Pāpaku fault zone comprises two main slip zones, referred to as the upper main brittle (304–321 mbsf) and lower subsidiary (351–361 mbsf) fault zones, and an intervening zoned, termed the lower ductile deformation zone. Two narrow zones, at the top of the main brittle fault zone, and one in a sand-rich interval above the subsidiary fault zone, experienced enhanced magnetic mineral diagenesis, which resulted in the recrystallization of ferrimagnetic greigite to paramagnetic pyrite. We propose that secondary magnetic mineral diagenesis was driven by anaerobic methane oxidation within these intervals, which occurs in the presence of methane and sulfate. We relate the observed changes to the fault parallel transport of fluids which is restricted to two damage zones. Overlying compacted and clay-rich sediments likely act as a barrier to upward advective flow through the fault zone and into the hanging wall. © 2021. The Authors.
英文关键词	diagenesis; fluid flow; greigite; rock magnetism; splay fault; subduction zone
语种	英语
来源期刊	Journal of Geophysical Research: Solid Earth
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/187335
作者单位	Paleomagnetic Laboratory ‘Fort Hoofddijk', Department of Earth Sciences, Utrecht University, Netherlands; Center for Advanced Marine Core Research, Kochi University, Nankoku, Japan
推荐引用方式 GB/T 7714	Greve A.,Kars M.,Dekkers M.J.. Fluid Accumulation, Migration and Anaerobic Oxidation of Methane Along a Major Splay Fault at the Hikurangi Subduction Margin (New Zealand): A Magnetic Approach[J],2021,126(2).
APA	Greve A.,Kars M.,&Dekkers M.J..(2021).Fluid Accumulation, Migration and Anaerobic Oxidation of Methane Along a Major Splay Fault at the Hikurangi Subduction Margin (New Zealand): A Magnetic Approach.Journal of Geophysical Research: Solid Earth,126(2).
MLA	Greve A.,et al."Fluid Accumulation, Migration and Anaerobic Oxidation of Methane Along a Major Splay Fault at the Hikurangi Subduction Margin (New Zealand): A Magnetic Approach".Journal of Geophysical Research: Solid Earth 126.2(2021).