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

Kód výsledku v 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>

Výsledek na webu

<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>

Jazyk výsledku

angličtina

Název v původním jazyce

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

Popis výsledku v původním jazyce

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.

Název v anglickém jazyce

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

Popis výsledku anglicky

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.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10505 - Geology

Projekt

<a href="/cs/project/GA14-25995S" target="_blank" >GA14-25995S: Nový pohled na diverzitu granitů z hlediska procesů migrace taveniny mezi zdrojem a plutonem</a><br>

Návaznosti

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

Rok uplatnění

2017

Kód důvěrnosti údajů

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

Název periodika

Geological Society of America Bulletin

ISSN

0016-7606

e-ISSN

—

Svazek periodika

129

Číslo periodika v rámci svazku

11/12

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

19

Strana od-do

1602-1621

Kód UT WoS článku

000414365400013

EID výsledku v databázi Scopus

—