The gabbro-diorite magmatism from the Narm area, western Kuh-e-Sarhangi (Central Iran): Evolution from Eocene magmatic flare up to Miocene asthenosphere upwelling

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F22%3A00560690" target="_blank" >RIV/67985831:_____/22:00560690 - isvavai.cz</a>

Výsledek na webu

<a href="https://www.sciencedirect.com/science/article/pii/S1464343X22002448" target="_blank" >https://www.sciencedirect.com/science/article/pii/S1464343X22002448</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jafrearsci.2022.104692" target="_blank" >10.1016/j.jafrearsci.2022.104692</a>

Jazyk výsledku

angličtina

Název v původním jazyce

The gabbro-diorite magmatism from the Narm area, western Kuh-e-Sarhangi (Central Iran): Evolution from Eocene magmatic flare up to Miocene asthenosphere upwelling

Popis výsledku v původním jazyce

Geodynamically, the Kashmar-Kerman Tectonic Zone (KKTZ) is one of the most perplexing tectonomagmatic belts of the Central Iran Microcontinent (CIM), comprising two important districts, Bafq and Kuh-e-Sarhangi. The Late Neoproterozoic-Early Cambrian granitoids, metamorphic rocks, and mildly metamorphosed volcansedimentary sequences are the oldest geologic outcrops in the Narm area, which is located in the western part of Kuh-e-Sarhangi. Alkaline gabbro-diorites with relatively high contents of K2O (1.99–3.03 wt%) and Na2O (2.7–5.99 wt%) are among the youngest intrusive rocks in the area, representing a within-plate provenience. These rocks were emplaced into Paleozoic sedimentary units as mafic-intermediate stocks, sills and dykes. Geochemically, these rocks could have resulted directly from partial melting (e.g., FeOT/MgO>1, Nb/La>0.5) with no considerable indication of assimilation with crustal materials (e.g., Ti/Zr > 30, Ti/Y > 200). Assimilation and fractional crystallization cannot account for magma evolution of gabbro-diorite rocks in the Narm area, using rare earth element ratios and geochemical models. There are also some geochemical signatures of an asthenospheric origin for the Narm gabbro-diorite rocks, such as the low ratios of La/Nb (1.5) and La/Ta (22). U–Pb zircon ages show that the Narm gabbro-diorites formed during two major episodes of magmatism in Central Iran: 40.3 ± 0.1 Ma in the Late Eocene (Bartonian) for gabbroic units and 8.04 ± 0.05 and 7.86 ± 0.05 in the late Miocene (Tartonian) for diorite stocks and diorite sills, respectively. Despite a time difference of more than thirty million years, geochemical similarities between the Eocene gabbro rocks and the Miocene diorite from the Narm area are striking. It is proposed that the best scenarios for the west of Kuh-e-Sarhangi mafic-intermediate magmatic pulses along with the deep faults of the Central Iran, are an Eocene magmatic flare up and a Miocene asthenosphere upwelling. Temporally and spatially, these rocks are comparable to the Cenozoic alkaline intrusive rocks of the Bafq region.

Název v anglickém jazyce

The gabbro-diorite magmatism from the Narm area, western Kuh-e-Sarhangi (Central Iran): Evolution from Eocene magmatic flare up to Miocene asthenosphere upwelling

Popis výsledku anglicky

Geodynamically, the Kashmar-Kerman Tectonic Zone (KKTZ) is one of the most perplexing tectonomagmatic belts of the Central Iran Microcontinent (CIM), comprising two important districts, Bafq and Kuh-e-Sarhangi. The Late Neoproterozoic-Early Cambrian granitoids, metamorphic rocks, and mildly metamorphosed volcansedimentary sequences are the oldest geologic outcrops in the Narm area, which is located in the western part of Kuh-e-Sarhangi. Alkaline gabbro-diorites with relatively high contents of K2O (1.99–3.03 wt%) and Na2O (2.7–5.99 wt%) are among the youngest intrusive rocks in the area, representing a within-plate provenience. These rocks were emplaced into Paleozoic sedimentary units as mafic-intermediate stocks, sills and dykes. Geochemically, these rocks could have resulted directly from partial melting (e.g., FeOT/MgO>1, Nb/La>0.5) with no considerable indication of assimilation with crustal materials (e.g., Ti/Zr > 30, Ti/Y > 200). Assimilation and fractional crystallization cannot account for magma evolution of gabbro-diorite rocks in the Narm area, using rare earth element ratios and geochemical models. There are also some geochemical signatures of an asthenospheric origin for the Narm gabbro-diorite rocks, such as the low ratios of La/Nb (1.5) and La/Ta (22). U–Pb zircon ages show that the Narm gabbro-diorites formed during two major episodes of magmatism in Central Iran: 40.3 ± 0.1 Ma in the Late Eocene (Bartonian) for gabbroic units and 8.04 ± 0.05 and 7.86 ± 0.05 in the late Miocene (Tartonian) for diorite stocks and diorite sills, respectively. Despite a time difference of more than thirty million years, geochemical similarities between the Eocene gabbro rocks and the Miocene diorite from the Narm area are striking. It is proposed that the best scenarios for the west of Kuh-e-Sarhangi mafic-intermediate magmatic pulses along with the deep faults of the Central Iran, are an Eocene magmatic flare up and a Miocene asthenosphere upwelling. Temporally and spatially, these rocks are comparable to the Cenozoic alkaline intrusive rocks of the Bafq region.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2022

Kód důvěrnosti údajů

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

Název periodika

Journal of African Earth Sciences

ISSN

1464-343X

e-ISSN

1879-1956

Svazek periodika

196

Číslo periodika v rámci svazku

December

Stát vydavatele periodika

GB - Spojené království Velké Británie a Severního Irska

Počet stran výsledku

17

Strana od-do

104692

Kód UT WoS článku

000859856500001

EID výsledku v databázi Scopus

2-s2.0-85136164811