Metamorphic and chronological constraints on the early Paleozoic tectono-thermal evolution of the Olkhon Terrane, southern Siberia

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F23%3A10168705" target="_blank" >RIV/00025798:_____/23:10168705 - isvavai.cz</a>

Result on the web

<a href="https://doi.org/10.1111/jmg.12706" target="_blank" >https://doi.org/10.1111/jmg.12706</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1111/jmg.12706" target="_blank" >10.1111/jmg.12706</a>

Result language

angličtina

Original language name

Metamorphic and chronological constraints on the early Paleozoic tectono-thermal evolution of the Olkhon Terrane, southern Siberia

Original language description

Terranes accreted to the southeastern margin of the Siberian Craton record an important early Paleozoic tectono-thermal event (known as the Baikal orogenic cycle) in the evolution of the Central Asian Orogenic Belt (CAOB). However, the precise metamorphic conditions and relative timing of this event and its linkage to the wider CAOB remain far poorly constrained. The best exposed of these terranes is the Olkhon Terrane on the western bank of Lake Baikal. Here, late Neoproterozoic through early Paleozoic island arc and back-arc assemblages were metamorphosed to form a thin granulite facies belt cropping out adjacent to the Siberian Craton and lower temperature/pressure paragneiss and migmatite towards the southeast. Phase equilibria modelling suggests that the granulite facies belt preserved moderate pressure (c. 0.80 GPa) and high temperature (up to 900 degrees C) conditions while the paragneiss and migmatites in the southeast have peak metamorphic conditions around 700-770 degrees C at 0.60-0.80 GPa. New geochronological data (zircon U-Pb in granulite and monazite U-Pb in paragneiss/migmatite) in combination with phase equilibria modelling and petro-structural analysis suggest that the tectono-metamorphic evolution of the Olkhon Terrane was controlled by a long-lasting (535-450 Ma) and pervasive thermal anomaly. Discrete maxima in the zircon and monazite U-Pb ages at c. 535, 500, and 450 Ma are linked to different stages of a semi-continuous high-temperature metamorphic evolution. Based on existing geological data of the region, a generalized geodynamic model for the Baikal orogenic cycle involving switching between compressional and extensional regimes during the early Paleozoic accretion of &apos;exotic&apos; CAOB-derived material to the southern margin of Siberia is proposed. The tectono-metamorphic evolution of the Olkhon Terrane may represent a world-class example of polyphase shortening of a long-lived hot intra-continental arc-back-arc system during its collision with cratonic blocks.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GX19-27682X" target="_blank" >GX19-27682X: Principal mechanisms of peripheral continental growth during supercontinent cycle</a><br>

Continuities

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Publication year

2023

Confidentiality

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

Name of the periodical

Journal of Metamorphic Geology

ISSN

0263-4929

e-ISSN

1525-1314

Volume of the periodical

41

Issue of the periodical within the volume

4

Country of publishing house

GB - UNITED KINGDOM

Number of pages

32

Pages from-to

525-556

UT code for WoS article

000914028000001

EID of the result in the Scopus database

2-s2.0-85146339463