Tectono-metamorphic evolution of a convergent back-arc: The Famatinian orogen, Sierra de Quilmes, Sierras Pampeanas, NW Argentina

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00025798%3A_____%2F17%3A00000342" target="_blank" >RIV/00025798:_____/17:00000342 - isvavai.cz</a>

Result on the web

<a href="http://dx.doi.org/10.1130/B31620.1" target="_blank" >http://dx.doi.org/10.1130/B31620.1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1130/B31620.1" target="_blank" >10.1130/B31620.1</a>

Result language

angličtina

Original language name

Tectono-metamorphic evolution of a convergent back-arc: The Famatinian orogen, Sierra de Quilmes, Sierras Pampeanas, NW Argentina

Original language description

Back-arcs are hot regions of enduring weakness in the hinterland of subduction zone s that are commonly sites of strain localisation, forming mobile belts that, in some cases, develop into major mountain belts. Their evolution results from their strength, a function of thickness, heat flux, and stresses. Contractional back-arcs may in some cases be too weak to form thick crusts, whereas in other cases contraction can lead to considerable crustal thickening and mountain building. The stress and thermal histories of back-arcs influence fundamentally their evolution, which can be retrieved from an investigation of the relationships between deformation and metamorphism. The 490–430 Famatinian orogen of the Sierras Pampeanas is associated with a back-arc with a complex development that remains imbued in speculation. We focus on the Sierra de Quilmes within the northern section of the back-arc, and present new structural data tied to anatexis and geochronology. We find low P/high T conditions prevailed over a ~35 m.y. thermal peak between 498 and 461 Ma indicated by U/Pb monazite ages of monazite. Anatexis coincided with thrusting to the west and northwest, as evidenced by leucosomes in axial planes of folds and in thrust planes. As rocks were thrust upward they cooled, melt solidified, and deformation localised into two major thrust zones. These record the same thrust-to-W and -NW kinematics as the earlier syn-anatectic deformation and ultimately placed hot rocks over cold ones. Continuous thrusting from peak metamorphism, through to cooling and strain localisation, is consistent with a number of shear zones in the northern Sierras Pampeanas. The low-pressure metamorphic assemblages indicate that shortening was not accompanied by pronounced crustal thickening, suggesting that the lithosphere was too hot, and the partially melted crust too weak for substantial stacking.

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

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OECD FORD branch

10505 - Geology

Project

<a href="/en/project/GA14-25995S" target="_blank" >GA14-25995S: Tracking magmas from source to pluton: new insight into granites diversity</a><br>

Continuities

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

Publication year

2017

Confidentiality

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

Name of the periodical

Geological Society of America Bulletin

ISSN

0016-7606

e-ISSN

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Volume of the periodical

129

Issue of the periodical within the volume

11/12

Country of publishing house

US - UNITED STATES

Number of pages

19

Pages from-to

1602-1621

UT code for WoS article

000414365400013

EID of the result in the Scopus database

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