Myrmekitic intergrowth of tourmaline and quartz in eclogite-hosting gneisses of the Tso Morari ultrahigh-pressure metamorphic terrane (Eastern Ladakh, India): a possible record of high-pressure conditions
Identifikátory výsledku
Kód výsledku v IS VaVaI
<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61989592%3A15310%2F19%3A73600638" target="_blank" >RIV/61989592:15310/19:73600638 - isvavai.cz</a>
Výsledek na webu
<a href="http://dx.doi.org/10.1144/SP481-2017-167" target="_blank" >http://dx.doi.org/10.1144/SP481-2017-167</a>
DOI - Digital Object Identifier
<a href="http://dx.doi.org/10.1144/SP481-2017-167" target="_blank" >10.1144/SP481-2017-167</a>
Alternativní jazyky
Jazyk výsledku
angličtina
Název v původním jazyce
Myrmekitic intergrowth of tourmaline and quartz in eclogite-hosting gneisses of the Tso Morari ultrahigh-pressure metamorphic terrane (Eastern Ladakh, India): a possible record of high-pressure conditions
Popis výsledku v původním jazyce
Alkaline schorlitic tourmaline with domains of myrmekitic quartz and tourmaline intergrowths is reported for the first time from quartzo-feldspathic gneisses of the Tso Morari Crystalline Complex (TMCC), eastern Ladakh Himalaya. Except for schorlitic tourmaline, the brown-green dravitic tourmaline occurs in melanocratic layers of the gneiss. The schorlitic tourmaline contains REE-rich apatite, which is a typical mineral formed under high-pressure (HP) conditions. The observed myrmekite, marked by vermicular quartz and tourmaline intergrowths, was probably formed during decompression as a consequence of excess silica released from recrystallized tourmaline. The recalculated composition of the tourmaline with quartz myrmekite suggests that Si also occupied the tourmaline octahedral Z site during the HP regime. During decompression excess Si from this tourmaline was replaced by Mg and Fe3+. At an early stage of exhumation needle-shaped schorlitic tourmaline II and mosaic zoning were formed. The excess of silica and the structural disorder suggest that the Si-oversaturated tourmaline was stable at high-pressure-ultrahigh-pressure (HP-UHP) conditions. The greater stability of dravitic tourmaline compared to schorlitic tourmaline at HP conditions is evidently recorded at the TMCC. The tourmaline-bearing gneisses of the TMCC most probably shared the same metamorphic conditions during Tertiary collision of the Indian and Eurasian plates, similar to that observed for the associated UHP eclogites
Název v anglickém jazyce
Myrmekitic intergrowth of tourmaline and quartz in eclogite-hosting gneisses of the Tso Morari ultrahigh-pressure metamorphic terrane (Eastern Ladakh, India): a possible record of high-pressure conditions
Popis výsledku anglicky
Alkaline schorlitic tourmaline with domains of myrmekitic quartz and tourmaline intergrowths is reported for the first time from quartzo-feldspathic gneisses of the Tso Morari Crystalline Complex (TMCC), eastern Ladakh Himalaya. Except for schorlitic tourmaline, the brown-green dravitic tourmaline occurs in melanocratic layers of the gneiss. The schorlitic tourmaline contains REE-rich apatite, which is a typical mineral formed under high-pressure (HP) conditions. The observed myrmekite, marked by vermicular quartz and tourmaline intergrowths, was probably formed during decompression as a consequence of excess silica released from recrystallized tourmaline. The recalculated composition of the tourmaline with quartz myrmekite suggests that Si also occupied the tourmaline octahedral Z site during the HP regime. During decompression excess Si from this tourmaline was replaced by Mg and Fe3+. At an early stage of exhumation needle-shaped schorlitic tourmaline II and mosaic zoning were formed. The excess of silica and the structural disorder suggest that the Si-oversaturated tourmaline was stable at high-pressure-ultrahigh-pressure (HP-UHP) conditions. The greater stability of dravitic tourmaline compared to schorlitic tourmaline at HP conditions is evidently recorded at the TMCC. The tourmaline-bearing gneisses of the TMCC most probably shared the same metamorphic conditions during Tertiary collision of the Indian and Eurasian plates, similar to that observed for the associated UHP eclogites
Klasifikace
Druh
C - Kapitola v odborné knize
CEP obor
—
OECD FORD obor
10505 - Geology
Návaznosti výsledku
Projekt
<a href="/cs/project/LO1305" target="_blank" >LO1305: Rozvoj centra pokročilých technologií a materiálů</a><br>
Návaznosti
P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)
Ostatní
Rok uplatnění
2019
Kód důvěrnosti údajů
S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů
Údaje specifické pro druh výsledku
Název knihy nebo sborníku
Crustal Architecture and Evolution of the Himalaya-Karakoram-Tibet Orogen
ISBN
978-1-78620-403-5
Počet stran výsledku
20
Strana od-do
175-194
Počet stran knihy
386
Název nakladatele
Geological Society Publishing House
Místo vydání
London
Kód UT WoS kapitoly
000505955200010