Volcano-tectonic evolution of a linear volcanic ridge (Pico-Faial Ridge, Azores Triple Junction) assessed by paleomagnetic studies

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F67985530%3A_____%2F18%3A00495314" target="_blank" >RIV/67985530:_____/18:00495314 - isvavai.cz</a>

Výsledek na webu

<a href="http://dx.doi.org/10.1016/j.jvolgeores.2018.01.005" target="_blank" >http://dx.doi.org/10.1016/j.jvolgeores.2018.01.005</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1016/j.jvolgeores.2018.01.005" target="_blank" >10.1016/j.jvolgeores.2018.01.005</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Volcano-tectonic evolution of a linear volcanic ridge (Pico-Faial Ridge, Azores Triple Junction) assessed by paleomagnetic studies

Popis výsledku v původním jazyce

The morphology of volcanic oceanic islands results from the interplay between constructive and destructive processes, and tectonics. In this study, the analysis of the paleomagnetic directions obtained on well-dated volcanic rocks is used as a tool to assess tilting related to tectonics and large-scale volcano instability along the Pico-Faial linear volcanic ridge (Azores Triple Junction, Central-North Atlantic). For this purpose, 530 specimens from 46 lava flows and one dyke from Pico and Faial islands were submitted to thermal and alternating magnetic fields demagnetizations. Detailed rock magnetic analyses, including thermomagnetic analyses and classical high magnetic field experiments revealed titanomagnetites with different Ti-content as the primary magnetic carrier, capable of recording stable remanent magnetizations. In both islands, the paleomagnetic analysis yields a Characteristic Remanent Magnetization, which presents island mean direction with normal and reversed polarities in agreement with the islands location and the age of the studied lava flows, indicating a primary thermoremanent magnetization. Field observations and paleomagnetic data show that lava flows were emplaced on pre-existing slopes and were later affected by significant tilting. In Faial Island, magmatic inflation and normal faults making up an island-scale graben, can be responsible for the tilting. In Pico Island, inflation related to magma intrusion during flow emplacement can be at the origin of the inferred tilting, whereas gradual downward movement of the SE flank by slumping processes appears mostly translational.

Název v anglickém jazyce

Volcano-tectonic evolution of a linear volcanic ridge (Pico-Faial Ridge, Azores Triple Junction) assessed by paleomagnetic studies

Popis výsledku anglicky

The morphology of volcanic oceanic islands results from the interplay between constructive and destructive processes, and tectonics. In this study, the analysis of the paleomagnetic directions obtained on well-dated volcanic rocks is used as a tool to assess tilting related to tectonics and large-scale volcano instability along the Pico-Faial linear volcanic ridge (Azores Triple Junction, Central-North Atlantic). For this purpose, 530 specimens from 46 lava flows and one dyke from Pico and Faial islands were submitted to thermal and alternating magnetic fields demagnetizations. Detailed rock magnetic analyses, including thermomagnetic analyses and classical high magnetic field experiments revealed titanomagnetites with different Ti-content as the primary magnetic carrier, capable of recording stable remanent magnetizations. In both islands, the paleomagnetic analysis yields a Characteristic Remanent Magnetization, which presents island mean direction with normal and reversed polarities in agreement with the islands location and the age of the studied lava flows, indicating a primary thermoremanent magnetization. Field observations and paleomagnetic data show that lava flows were emplaced on pre-existing slopes and were later affected by significant tilting. In Faial Island, magmatic inflation and normal faults making up an island-scale graben, can be responsible for the tilting. In Pico Island, inflation related to magma intrusion during flow emplacement can be at the origin of the inferred tilting, whereas gradual downward movement of the SE flank by slumping processes appears mostly translational.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10507 - Volcanology

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2018

Kód důvěrnosti údajů

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

Název periodika

Journal of Volcanology and Geothermal Research

ISSN

0377-0273

e-ISSN

—

Svazek periodika

352

Číslo periodika v rámci svazku

February

Stát vydavatele periodika

NL - Nizozemsko

Počet stran výsledku

14

Strana od-do

78-91

Kód UT WoS článku

000428009600006

EID výsledku v databázi Scopus

2-s2.0-85041137482