Intergranular coesite and coesite inclusions in dolomite from the Dabie Shan: Constraints on the preservation of coesite in UHP rocks

Terra Nova ◽  
2017 ◽  
Vol 29 (3) ◽  
pp. 154-161 ◽  
Author(s):  
Penglei Liu ◽  
Hans-Joachim Massonne ◽  
Junfeng Zhang ◽  
Yao Wu ◽  
Zhenmin Jin
Keyword(s):  
Dabie Shan

scholarly journals Rheological Contrast between Quartz and Coesite Generates Strain Localization in Deeply Subducted Continental Crust

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 842
Author(s):  
Kouhei Asano ◽  
Katsuyoshi Michibayashi ◽  
Tomohiro Takebayashi
Keyword(s):  
Rheological Behavior ◽  
Strain Localization ◽  
Shear Zones ◽  
Ultrahigh Pressure ◽  
Ultramafic Rocks ◽  
Crustal Material ◽  
Orientation Data ◽  
Crystallographic Preferred Orientation ◽  
Dabie Shan ◽  
Felsic Rocks

Deformation microstructures of peak metamorphic conditions in ultrahigh-pressure (UHP) metamorphic rocks constrain the rheological behavior of deeply subducted crustal material within a subduction channel. However, studies of such rocks are limited by the overprinting effects of retrograde metamorphism during exhumation. Here, we present the deformation microstructures and crystallographic-preferred orientation data of minerals in UHP rocks from the Dabie–Shan to study the rheological behavior of deeply subducted continental material under UHP conditions. The studied samples preserve deformation microstructures that formed under UHP conditions and can be distinguished into two types: high-strain mafic–ultramafic samples (eclogite and garnet-clinopyroxenite) and low-strain felsic samples (jadeite quartzite). This distinction suggests that felsic rocks are less strained than mafic–ultramafic rocks under UHP conditions. We argue that the phase transition from quartz to coesite in the felsic rocks may explain the microstructural differences between the studied mafic–ultramafic and felsic rock samples. The presence of coesite, which has a higher strength than quartz, may result in an increase in the bulk strength of felsic rocks, leading to strain localization in nearby mafic–ultramafic rocks. The formation of shear zones associated with strain localization under HP/UHP conditions can induce the detachment of subducted crustal material from subducting lithosphere, which is a prerequisite for the exhumation of UHP rocks. These findings suggest that coesite has an important influence on the rheological behavior of crustal material that is subducted to coesite-stable depths.

High-Si phengite, mineral chemistry and P-T evolution of ultra-high-pressure eclogites and calc-silicates from the Dabie Shan, eastern China

2000 ◽  
Vol 35 (3-4) ◽  
pp. 185-207 ◽  
Author(s):  
Robert Schmid ◽  
Leander Franz ◽  
Roland Oberhänsli ◽  
Shuwen Dong
Keyword(s):  
High Pressure ◽  
Eastern China ◽  
Mineral Chemistry ◽  
Ultra High Pressure ◽  
Dabie Shan

What brought them up? Exhumation of the Dabie Shan ultrahigh-pressure rocks

Geology ◽  
1995 ◽  
Vol 23 (8) ◽  
pp. 743 ◽  
Author(s):  
Bradley R. Hacker ◽  
Lothar Ratschbacher ◽  
Laura Webb ◽  
Dong Shuwen
Keyword(s):  
Ultrahigh Pressure ◽  
Dabie Shan

Collision and rotation of the South China block and their role in the formation and exhumation of ultrahigh pressure rocks in the Dabie Shan orogen

Terra Nova ◽  
2012 ◽  
Vol 24 (5) ◽  
pp. 339-350 ◽  
Author(s):  
Xiaoyu Guo ◽  
John Encarnacion ◽  
Xiao Xu ◽  
Alan Deino ◽  
Zhiwu Li ◽  
...  
Keyword(s):  
South China ◽  
Ultrahigh Pressure ◽  
South China Block ◽  
The South ◽  
Dabie Shan

A coesite inclusion in dolomite in Dabie Shan, China: Petrological and rheological significance

1994 ◽  
Vol 6 (6) ◽  
pp. 995-1000 ◽  
Author(s):  
Hans-Peter Schertl ◽  
Aral I. Okay
Keyword(s):  
Dabie Shan
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