Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985831%3A_____%2F19%3A00504671" target="_blank" >RIV/67985831:_____/19:00504671 - isvavai.cz</a>

Nalezeny alternativní kódy

RIV/00216208:11310/19:10394634

Výsledek na webu

<a href="https://pubs.geoscienceworld.org/gsa/gsabulletin/article/131/5-6/997/566860/Emplacement-dynamics-of-syncollapse-ring-dikes-An" target="_blank" >https://pubs.geoscienceworld.org/gsa/gsabulletin/article/131/5-6/997/566860/Emplacement-dynamics-of-syncollapse-ring-dikes-An</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1130/B35019.1" target="_blank" >10.1130/B35019.1</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif

Popis výsledku v původním jazyce

The late Carboniferous Altenberg-Teplice caldera in the northwestern Bohemian Massif provides an intriguing example of rhyolite eruptions evolving to a trapdoor collapse and coeval ring dike emplacement. Geochemical data suggest that withdrawal of an underlying stratified magma chamber beneath the caldera took place in two steps. Eruptions of the reversely zoned Teplice rhyolite drained the chamber, followed by a trapdoor collapse of the caldera floor and emplacement of voluminous microgranite ring dike system at 312 Ma. The mechanism proposed here is that the subsiding caldera floor increased vertical load on the magma chamber and triggered remobilization of residual, cumulate-like, and otherwise non-eruptible magma mush. The magnetic fabrics (determined using the anisotropy of magnetic susceptibility [AMS]), carried by paramagnetic ferrosilicates and titanomagnetite, indicate that the ring dike magma first flowed upwards via four main feeder domains from which the magma was then distributed laterally. The asymmetric trapdoor collapse generated domains of dilation and contraction along the caldera limit, evidenced by different shapes of fabric ellipsoids and uneven apparent width of the individual ring dike segments. Based on this case example, we develop a general kinematic model for polyphase caldera collapse and ring dike emplacement, invoking a combination of multiple space-making processes: piston and trapdoor collapses together with downsag and faulting of the caldera floor, regional tectonic extension, reactivation of the preexisting structures, and volume changes in the caldera floor due to thermal stresses.

Název v anglickém jazyce

Emplacement dynamics of syn-collapse ring dikes: An example from the Altenberg-Teplice caldera, Bohemian Massif

Popis výsledku anglicky

The late Carboniferous Altenberg-Teplice caldera in the northwestern Bohemian Massif provides an intriguing example of rhyolite eruptions evolving to a trapdoor collapse and coeval ring dike emplacement. Geochemical data suggest that withdrawal of an underlying stratified magma chamber beneath the caldera took place in two steps. Eruptions of the reversely zoned Teplice rhyolite drained the chamber, followed by a trapdoor collapse of the caldera floor and emplacement of voluminous microgranite ring dike system at 312 Ma. The mechanism proposed here is that the subsiding caldera floor increased vertical load on the magma chamber and triggered remobilization of residual, cumulate-like, and otherwise non-eruptible magma mush. The magnetic fabrics (determined using the anisotropy of magnetic susceptibility [AMS]), carried by paramagnetic ferrosilicates and titanomagnetite, indicate that the ring dike magma first flowed upwards via four main feeder domains from which the magma was then distributed laterally. The asymmetric trapdoor collapse generated domains of dilation and contraction along the caldera limit, evidenced by different shapes of fabric ellipsoids and uneven apparent width of the individual ring dike segments. Based on this case example, we develop a general kinematic model for polyphase caldera collapse and ring dike emplacement, invoking a combination of multiple space-making processes: piston and trapdoor collapses together with downsag and faulting of the caldera floor, regional tectonic extension, reactivation of the preexisting structures, and volume changes in the caldera floor due to thermal stresses.

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

2019

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

131

Číslo periodika v rámci svazku

5/6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

20

Strana od-do

997-1016

Kód UT WoS článku

000466511700015

EID výsledku v databázi Scopus

2-s2.0-85066755974