DOI: 10.1016/j.tecto.2021.228883
论文题名: Frictional properties of basalt experimental faults and implications for volcano-tectonic settings and geo-energy sites
作者: Giacomel P. ; Ruggieri R. ; Scuderi M.M. ; Spagnuolo E. ; Di Toro G. ; Collettini C.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 811 语种: 英语
中文关键词: Fault slip modes
; Frictional stability analysis
; Heterogeneous fault microstructure
; Strong faults
; Unaltered basalts
英文关键词: Basalt
; Faulting
; Shear flow
; Velocity
; Volcanoes
; Dry and wet conditions
; Friction coefficients
; Frictional properties
; Frictional stability
; Grain-size reduction
; Microstructural heterogeneity
; Scientific drilling
; Shear localizations
; Friction
; basalt
; drilling
; fault
; fault gouge
; friction
; nucleation
; shear zone
; slip
; stability analysis
; stress
; tectonic setting
英文摘要: We performed a suite of experiments aimed at examining the frictional properties of unaltered basalts at conditions considered to be representative of slip at shallow depths in volcano-tectonic environments and in-situ geo-energy basaltic sites. Scientific drilling and field studies on exhumed subsurface faults and fractures analogues suggest that, frictional sliding in basalts can occur in shear zones within a volume of wear debris or along localized joint surfaces. To illuminate how microstructural heterogeneities affect the nucleation of slip instabilities in basalts, we sheared simulated fault gouge and bare rock surfaces at low normal stresses (4–30 MPa) at ambient temperature, under room-dry and wet conditions. We performed velocity steps (0.1–300 μm/s) and slide-hold-slides (30–3000 s holds) to determine the frictional stability and healing properties of basalts. In all the tests, we observed high friction coefficient associated with important frictional restrengthening. Overall, our results show that microstructural heterogeneities strongly affect the friction velocity dependence of basalts: while for normal stresses ≥10 MPa, shear localization accompanied by cataclasis and grain size reduction favors the transition to velocity weakening behavior of powdered samples, on bare surfaces gouge production during shearing promotes a transition to a velocity strengthening behavior. Our results imply that at the tested conditions, friction instabilities may promptly nucleate in shear zones where deformation within (unaltered) basaltic gouge layers is localized, such as those located along volcanic flanks, while joint surfaces characterized by rough rock-on-rock contacts are less prone to unstable slip, which is suppressed at velocities ≥10 μm/s. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170810
Appears in Collections: 气候变化与战略
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作者单位: Dipartimento di Scienze della Terra, Sapienza Università di Roma, Piaz. Aldo Moro 5, Rome, Italy; Istituto Nazionale di Geofisica e Vulcanologia, Via di Vigna Murata 605, Rome, Italy; Dipartimento di Geoscienze, Università degli Studi di Padova, Via G. Gradenigo 6, Padua, Italy
Recommended Citation:
Giacomel P.,Ruggieri R.,Scuderi M.M.,et al. Frictional properties of basalt experimental faults and implications for volcano-tectonic settings and geo-energy sites[J]. Tectonophysics,2021-01-01,811