DOI: 10.1016/j.epsl.2021.116930
论文题名: A common type of mineralogical banding in serpentine crack-seal veins
作者: Tarling M.S. ; Smith S.A.F. ; Rooney J.S. ; Viti C. ; Gordon K.C.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2021
卷: 564 语种: 英语
中文关键词: chrysotile
; crack-seal
; lizardite
; polygonal serpentine
; repetitive slip
; serpentinite
英文关键词: Faulting
; Growth kinetics
; High resolution transmission electron microscopy
; Kaolinite
; Magnesite
; Mapping
; Scanning electron microscopy
; Crack opening
; Crack sealing
; Crack-seal
; Environmental conditions
; Fault kinematics
; Lizardite
; Polygonal serpentines
; Repetitive slip
; Serpentinite
; Ultramafic rocks
; Serpentine
; asbestos
; crack
; experimental mineralogy
; lizardite
; mineralogy
; polygon
; Raman spectroscopy
; sealing
; serpentine
; vein (geology)
英文摘要: Serpentine veins are ubiquitous in hydrated and deformed ultramafic rocks, and have previously been used to track fault kinematics and understand the evolution of environmental conditions during vein formation. However, difficulties in unambiguously identifying and mapping serpentine types at sub-micron to mm scales has limited our understanding of vein precipitation kinetics and growth histories. Using recently developed techniques of Raman spectroscopy mapping, combined with scanning- and transmission-electron microscopy, we describe a new type of mineralogically banded serpentine crack-seal vein in six samples from different settings around the world. In all of the studied samples, individual bands comprise a thin layer (∼0.4–2 μm) dominated by chrysotile and a much thicker layer (∼0.5–30 μm) dominated by polygonal serpentine/lizardite. Existing field and experimental data suggest that disequilibrium conditions immediately following crack opening may favour rapid precipitation of chrysotile along one of the crack margins. Subsequently, diffusional transport of elements favours slower precipitation of polygonal serpentine/lizardite which leads to crack sealing. The similarities in layer thicknesses and mineralogy exhibited by samples collected from extension and shear veins, dilational jogs, foliation surfaces, and the margins of phacoids, suggest that a common set of processes involving crack opening and sealing are active in a range of different structural sites within serpentinite-bearing faults and shear zones, potentially associated with repetitive slip events such as small repeating earthquakes. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/165684
Appears in Collections: 气候变化与战略
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作者单位: Department of Geology, University of Otago, 360 Leith Street, Dunedin, 9016, New Zealand; Department of Chemistry, University of Otago, Union Place West, Dunedin, 9016, New Zealand; Università degli Studi di Siena, Dipartimento di Scienze Fisiche, della Terra e dell'Ambiente, Siena, Italy
Recommended Citation:
Tarling M.S.,Smith S.A.F.,Rooney J.S.,et al. A common type of mineralogical banding in serpentine crack-seal veins[J]. Earth and Planetary Science Letters,2021-01-01,564