Validity of the stress inversion of orientation data from a dike swarm with a radial-parallel pattern transition

2021 ◽  
pp. 104485
Author(s):  
Kentaro Ushimaru ◽  
Atsushi Yamaji
Keyword(s):  
Stress Inversion ◽  
Orientation Data ◽  
Dike Swarm ◽  
Parallel Pattern

PETROGENESIS, AGE, AND CORRELATION OF THE KAZAN DIKE SWARM, NUNAVUT, CANADA: IMPLICATIONS FOR AN ABORTED RIFT ORIGIN FOR THE SNOWBIRD TECTONIC ZONE

2016 ◽  
Author(s):  
Lisa J. Grohn ◽  
◽  
Sean P. Regan ◽  
Michael L. Williams ◽  
Larissa De Santana Do Nascimento ◽  
...  
Keyword(s):  
Tectonic Zone ◽  
Dike Swarm

FOUR MILLION YEARS FROM INTRUSION TO ERUPTION IN THE WHITE PINE STOCK AND EAST TRAVERSE MOUNTAINS PEBBLE DIKE SWARM, WASATCH MOUNTAINS, UTAH, U.S.A

2017 ◽  
Author(s):  
Michael Stearns ◽  
◽  
Collin Jensen ◽  
Jeffrey D. Keith ◽  
Eric H. Christiansen
Keyword(s):  
White Pine ◽  
Dike Swarm ◽  
Wasatch Mountains

scholarly journals Seismicity, focal mechanism, and stress tensor analysis of the Simav region, western Turkey

2020 ◽  
Vol 12 (1) ◽  
pp. 479-490
Author(s):  
Ahu Kömeç Mutlu
Keyword(s):  
Moment Tensor ◽  
Aftershock Sequence ◽  
Movement Direction ◽  
Normal Faults ◽  
Normal Faulting ◽  
Stress Inversion ◽  
Western Turkey ◽  
Stress Orientations ◽  
Extension Direction ◽  
Inversion Analysis

AbstractThis study focuses on the seismicity and stress inversion analysis of the Simav region in western Turkey. The latest moderate-size earthquake was recorded on May 19, 2011 (Mw 5.9), with a dense aftershock sequence of more than 5,000 earthquakes in 6 months. Between 2004 and 2018, data from earthquake events with magnitudes greater than 0.7 were compiled from 86 seismic stations. The source mechanism of 54 earthquakes with moment magnitudes greater than 3.5 was derived by using a moment tensor inversion. Normal faults with oblique-slip motions are dominant being compatible with the NE-SW extension direction of western Turkey. The regional stress field is assessed from focal mechanisms. Vertically oriented maximum compressional stress (σ1) is consistent with the extensional regime in the region. The σ1 and σ3 stress axes suggest the WNW-ESE compression and the NNE-SSW dilatation. The principal stress orientations support the movement direction of the NE-SW extension consistent with the mainly observed normal faulting motions.

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.

scholarly journals Dandelion Diagram: Aggregating Positioning and Orientation Data in the Visualization of Classroom Proxemics

2020 ◽  
Author(s):  
Pengcheng An ◽  
Saskia Bakker ◽  
Sara Ordanovski ◽  
Chris L.E. Paffen ◽  
Ruurd Taconis ◽  
...  
Keyword(s):  
Orientation Data

A Simple Algorithm to Eliminate Ambiguities in EBSD Orientation Map Visualization and Analyses: Application to Fatigue Crack-Tips/Wakes in Aluminum Alloys

2010 ◽  
Vol 16 (6) ◽  
pp. 831-841 ◽  
Author(s):  
Vipul K. Gupta ◽  
Sean R. Agnew
Keyword(s):  
Fatigue Crack ◽  
Aluminum Alloys ◽  
Direct Determination ◽  
Simple Algorithm ◽  
Electron Backscattered Diffraction ◽  
Lattice Curvature ◽  
Orientation Data ◽  
Orientation Map ◽  
Crack Tips ◽  
Map Visualization

AbstractA simple algorithm is developed and implemented to eliminate ambiguities, in both statistical analyses of orientation data (e.g., orientation averaging) and electron backscattered diffraction (EBSD) orientation map visualization, caused by symmetrically equivalent orientations and the wrap-around or umklapp effect. Using crystal symmetry operators and the lowest Euclidian-distance criterion, the orientation of each pixel within a grain is redefined. An advantage of this approach is demonstrated for direct determination of the representative orientation of a grain within an EBSD map by mean, median, or quaternion-based averaging methods that can be further used within analyses or visualization of misorientation or geometrically necessary dislocation (GND) density. If one also considers the lattice curvature tensor, five components of the dislocation density tensor—corresponding to a part of the GND content—may be inferred. The methodology developed is illustrated using EBSD orientation data obtained from the fatigue crack-tips/wakes in aerospace aluminum alloys 2024-T351 and 7050-T7451.

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