Effect of pressure on the deformation of quartz aggregates in the presence of H2O

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F21%3A10435415" target="_blank" >RIV/00216208:11310/21:10435415 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=V7fXmNGyO0" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=V7fXmNGyO0</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jsg.2021.104351" target="_blank" >10.1016/j.jsg.2021.104351</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Effect of pressure on the deformation of quartz aggregates in the presence of H2O

Popis výsledku v původním jazyce

Quartzite samples of high purity with a grain size of similar to 200 mu m have been experimentally deformed by coaxial shortening in a solid medium apparatus at 900 degrees C and at confining pressures ranging from 0.6 to 2 GPa. Most samples have been shortened by similar to 30% with 0.1 wt% added H2O. The samples deformed dominantly by crystal plasticity (dislocation creep), and there is a systematic decrease of flow stress with increasing confining pressure. Strain rate stepping tests yield stress exponents of n approximate to 1.4. The strain determined from individual grain shapes matches that determined from bulk shortening. In addition to plastic strain, mode I cracks developed in all samples, principally in the grain boundary regions. Recrystallized material, visible through cathodoluminescence colours, forms by two mechanisms: (1) progressive subgrain rotation and (2) cracking, nucleating small new grains. After high-angle boundaries have been established, grain boundary migration takes place, and a distinction of new grains nucleation origin (subgrain rotation or cracking) is impossible. At higher pressure, there is more recrystallized material forming in the deformed samples, and it is inferred that the inverse pressure dependence of flow stress is caused by enhanced grain boundary migration at higher pressure, consistent with previous studies.

Název v anglickém jazyce

Effect of pressure on the deformation of quartz aggregates in the presence of H2O

Popis výsledku anglicky

Quartzite samples of high purity with a grain size of similar to 200 mu m have been experimentally deformed by coaxial shortening in a solid medium apparatus at 900 degrees C and at confining pressures ranging from 0.6 to 2 GPa. Most samples have been shortened by similar to 30% with 0.1 wt% added H2O. The samples deformed dominantly by crystal plasticity (dislocation creep), and there is a systematic decrease of flow stress with increasing confining pressure. Strain rate stepping tests yield stress exponents of n approximate to 1.4. The strain determined from individual grain shapes matches that determined from bulk shortening. In addition to plastic strain, mode I cracks developed in all samples, principally in the grain boundary regions. Recrystallized material, visible through cathodoluminescence colours, forms by two mechanisms: (1) progressive subgrain rotation and (2) cracking, nucleating small new grains. After high-angle boundaries have been established, grain boundary migration takes place, and a distinction of new grains nucleation origin (subgrain rotation or cracking) is impossible. At higher pressure, there is more recrystallized material forming in the deformed samples, and it is inferred that the inverse pressure dependence of flow stress is caused by enhanced grain boundary migration at higher pressure, consistent with previous studies.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

S - Specificky vyzkum na vysokych skolach<br>I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2021

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Structural Geology

ISSN

0191-8141

e-ISSN

—

Svazek periodika

148

Číslo periodika v rámci svazku

July

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

104351

Kód UT WoS článku

000663777800001

EID výsledku v databázi Scopus

2-s2.0-85105009695