Geochemical and geochronological constraints on distinct Early-Neoproterozoic and Cambrian accretionary events along southern margin of the Baydrag Continent in western Mongolia

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11310%2F17%3A10363694" target="_blank" >RIV/00216208:11310/17:10363694 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00025798:_____/17:00000028

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.gr.2016.09.008" target="_blank" >http://dx.doi.org/10.1016/j.gr.2016.09.008</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.gr.2016.09.008" target="_blank" >10.1016/j.gr.2016.09.008</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Geochemical and geochronological constraints on distinct Early-Neoproterozoic and Cambrian accretionary events along southern margin of the Baydrag Continent in western Mongolia

Popis výsledku v původním jazyce

New geological, geochemical and geochronological data characterize architecture and geodynamic evolution of the southern Baydrag continental margin in Mongolia. The structurally deepest Zamtyn Nuruu Complex is composed of highly deformed orthogneisses and amphibolites intruded by syn-tectonic diorites and gabbros. Geochemical affinity of the amphibolites varies from continental-arc to within-plate tholeiites, while the Grenvillean (948 +/- 6 and 941 +/- 11 Ma) orthogneisses show features typical of magmatic-arc origin. The syn-metamorphic gabbros and diorites intruded coevally with the regional thermal event at 542 +/- 4 Ma. Zircon Hf isotope and whole-rock geochemical data point to a primitive source of mafic rocks, most likely formed in Early Cambrian arc developed on Grenvillean basement. The overlying Alag Khadny subduction melange contains eclogites and amphibolites with MORB affinity while lenses of orthogneisses (953 +/- 12 Ma: zircon, 939 +/- 5 Ma: monazite) reveal late-to post-collisional signature. The subduction event is dated by zircon at ca. 538 +/- 20 Ma. The matrix of the melange consists of metapelites and carbonates, most likely fragments of Neoproterozoic to Early Cambrian carbonate platform scrapped off the subducting plate during the mid-Cambrian accretion. The hanging-wall Khan-Taishir-Erdene Uul ophiolite is formed by Neoproterozoic pillow lavas, red cherts and associated ultramafic rocks, with gabbros dated at 973 +/- 12 Ma. Taken together, the Zamtyn Nuruu Grenvillean arc is interpreted as a result of Mirovoi Ocean subduction beneath Rodinian margin, while the Early Cambrian diorites and gabbros testify initiation of supra-subduction magmatism of Palaeo-Pacific plate beneath continental fragment of Gondwanan, most likely Tarim affinity. These two events were separated by the development of Neoproterozoic passive margin probably associated with Rodinia fragmentation.

Název v anglickém jazyce

Geochemical and geochronological constraints on distinct Early-Neoproterozoic and Cambrian accretionary events along southern margin of the Baydrag Continent in western Mongolia

Popis výsledku anglicky

New geological, geochemical and geochronological data characterize architecture and geodynamic evolution of the southern Baydrag continental margin in Mongolia. The structurally deepest Zamtyn Nuruu Complex is composed of highly deformed orthogneisses and amphibolites intruded by syn-tectonic diorites and gabbros. Geochemical affinity of the amphibolites varies from continental-arc to within-plate tholeiites, while the Grenvillean (948 +/- 6 and 941 +/- 11 Ma) orthogneisses show features typical of magmatic-arc origin. The syn-metamorphic gabbros and diorites intruded coevally with the regional thermal event at 542 +/- 4 Ma. Zircon Hf isotope and whole-rock geochemical data point to a primitive source of mafic rocks, most likely formed in Early Cambrian arc developed on Grenvillean basement. The overlying Alag Khadny subduction melange contains eclogites and amphibolites with MORB affinity while lenses of orthogneisses (953 +/- 12 Ma: zircon, 939 +/- 5 Ma: monazite) reveal late-to post-collisional signature. The subduction event is dated by zircon at ca. 538 +/- 20 Ma. The matrix of the melange consists of metapelites and carbonates, most likely fragments of Neoproterozoic to Early Cambrian carbonate platform scrapped off the subducting plate during the mid-Cambrian accretion. The hanging-wall Khan-Taishir-Erdene Uul ophiolite is formed by Neoproterozoic pillow lavas, red cherts and associated ultramafic rocks, with gabbros dated at 973 +/- 12 Ma. Taken together, the Zamtyn Nuruu Grenvillean arc is interpreted as a result of Mirovoi Ocean subduction beneath Rodinian margin, while the Early Cambrian diorites and gabbros testify initiation of supra-subduction magmatism of Palaeo-Pacific plate beneath continental fragment of Gondwanan, most likely Tarim affinity. These two events were separated by the development of Neoproterozoic passive margin probably associated with Rodinia fragmentation.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GAP210%2F12%2F2205" target="_blank" >GAP210/12/2205: Růst kontintální kůry a konstrukce kontinentu na příkladu Centrálního asijského orogenního pásu</a><br>

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

Gondwana Research

ISSN

1342-937X

e-ISSN

—

Svazek periodika

47

Číslo periodika v rámci svazku

July 2017

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

28

Strana od-do

200-227

Kód UT WoS článku

000400971500011

EID výsledku v databázi Scopus

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