Shock-darkening in ordinary chondrites: Determination of the pressure-temperature conditions by shock physics mesoscale modeling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F17%3A00481577" target="_blank" >RIV/67985831:_____/17:00481577 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1111/maps.12935" target="_blank" >http://dx.doi.org/10.1111/maps.12935</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/maps.12935" target="_blank" >10.1111/maps.12935</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Shock-darkening in ordinary chondrites: Determination of the pressure-temperature conditions by shock physics mesoscale modeling

Popis výsledku v původním jazyce

We determined the shock-darkening pressure range in ordinary chondrites using the iSALE shock physics code. We simulated planar shock waves on a mesoscale in a sample layer at different nominal pressures. Iron and troilite grains were resolved in a porous olivine matrix in the sample layer. We used equations of state (Tillotson EoS and ANEOS) and basic strength and thermal properties to describe the material phases. We used Lagrangian tracers to record the peak shock pressures in each material unit. The post-shock temperatures (and the fractions of the tracers experiencing temperatures above the melting point) for each material were estimated after the passage of the shock wave and after the reflections of the shock at grain boundaries in the heterogeneous materials. The results showed that shock-darkening, associated with troilite melt and the onset of olivine melt, happened between 40 and 50 GPa with 52 GPa being the pressure at which all tracers in the troilite material reach the melting point. We demonstrate the difficulties of shock heating in iron and also the importance of porosity. Material impedances, grain shapes, and the porosity models available in the iSALE code are discussed. We also discuss possible not-shock-related triggers for iron melt.

Název v anglickém jazyce

Shock-darkening in ordinary chondrites: Determination of the pressure-temperature conditions by shock physics mesoscale modeling

Popis výsledku anglicky

We determined the shock-darkening pressure range in ordinary chondrites using the iSALE shock physics code. We simulated planar shock waves on a mesoscale in a sample layer at different nominal pressures. Iron and troilite grains were resolved in a porous olivine matrix in the sample layer. We used equations of state (Tillotson EoS and ANEOS) and basic strength and thermal properties to describe the material phases. We used Lagrangian tracers to record the peak shock pressures in each material unit. The post-shock temperatures (and the fractions of the tracers experiencing temperatures above the melting point) for each material were estimated after the passage of the shock wave and after the reflections of the shock at grain boundaries in the heterogeneous materials. The results showed that shock-darkening, associated with troilite melt and the onset of olivine melt, happened between 40 and 50 GPa with 52 GPa being the pressure at which all tracers in the troilite material reach the melting point. We demonstrate the difficulties of shock heating in iron and also the importance of porosity. Material impedances, grain shapes, and the porosity models available in the iSALE code are discussed. We also discuss possible not-shock-related triggers for iron melt.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10308 - Astronomy (including astrophysics,space science)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Meteoritics & Planetary Science

ISSN

1086-9379

e-ISSN

—

Svazek periodika

52

Číslo periodika v rámci svazku

11

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

16

Strana od-do

2375-2390

Kód UT WoS článku

000414860200006

EID výsledku v databázi Scopus

2-s2.0-85033241577