DOI: 10.1016/j.tecto.2021.228778
论文题名: Feldspar microboudinage paleopiezometer and its applications to estimating differential stress magnitudes in the continental middle crust (examples from west Yunnan, China)
作者: Ji S. ; Li L.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 805 语种: 英语
中文关键词: Boudinage
; Crustal rheology
; Feldspar
; Piezometer
; Southeastern Tibet Plateau
; Yunnan
英文关键词: Chromite
; Fracture
; Mica
; Quartz
; Structural geology
; Tensile strength
; Brittle ductile transitions
; Continental collisions
; Crustal-scale shear zones
; Deformation temperatures
; Differential stress
; Dislocation creep
; Recrystallized grain sizes
; Rheological property
; Feldspar
; boudinage
; continental collision
; continental crust
; exhumation
; feldspar
; piezometer
; rheology
; shear zone
; stress
; China
; Qinghai-Xizang Plateau
; Yunnan
英文摘要: Feldspar, which is the most abundant crustal mineral, exhibits brittle behavior while quartz and mica deform plastically by dislocation creep, under the greenschist-facies conditions (300–450 °C). Pull-apart microboudinage, which formed by repeated cycles of tensile fractures, is a common microstructure observed in feldspar porphyroclasts embedded in the ductile matrix of quartz in granitic mylonites from the Red River, Chongshan and Gaoligong shear zones (Yunnan, China). These crustal-scale shear zones, which lie in the southeastern margin of the Tibet Plateau, have played a critical role in the southeastward lateral extrusion of the Indochina composite block in response to the Indo-Asian continental collision. Here we developed a feldspar microboudinage paleopiezometer. In each feldspar porphyroclast, the differential stresses estimated from microboudins progressively increases with sequential fracturing, depicting an evolution during exhumation of the mylonite upwards the brittle-ductile transition. The results from the feldspar microboudinage piezometer and the quartz recrystallized grain-size piezometer are largely consistent within the range of uncertainties. The microboudinage piezometer, combined with results of finite strain measurements, deformation temperature estimates, and thermochronological data, can yield the valuable information about rheological properties of naturally deformed rocks. It can also be directly used or adapted to a wide range of geological problems, for example, fractured pebbles in an unlithified matrix, chromite pods in serpentinized mantle rocks, and strong boudins in a soft material at any scale. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170828
Appears in Collections: 气候变化与战略
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作者单位: Département des Génies Civil, Géologique et des Mines, École Polytechnique de Montréal, Montréal, Québec H3C 3A7, Canada
Recommended Citation:
Ji S.,Li L.. Feldspar microboudinage paleopiezometer and its applications to estimating differential stress magnitudes in the continental middle crust (examples from west Yunnan, China)[J]. Tectonophysics,2021-01-01,805