V. O. Davydova, I. N. Bindeman, M. D. Shchekleina, S. N. Rychagov
{"title":"Pauzhetka Caldera (South Kamchatka): Еxploring Temporal Evolution and Origin of Voluminous Silicic Magmatism","authors":"V. O. Davydova, I. N. Bindeman, M. D. Shchekleina, S. N. Rychagov","doi":"10.1134/S0869591122050022","DOIUrl":null,"url":null,"abstract":"<div><p>The Pauzhetka Caldera (27 × 18 km) was formed in the South Kamchatka during the Golygin Ignimbrite eruption (420–440 ka), the largest known eruption in the region in the past 1 Myr. The eruption was preceded by the 3 Ma-old mafic and intermediate volcanism. After the caldera-forming eruption, a variety of products, from basalt to rhyolite, were ejected within the caldera. For understanding the origin of voluminous silicic magmatism in thin mafic South Kamchatka crust, we used geochemical and isotope data. Our research has characterized the major and trace element composition of Golygin ignimbrite, intra-caldera hydrothermally altered deposits, pre-caldera (Mt. Orlinoe Krylo, Mt. Klyuchevskaya) and post-caldera (Kambalny Ridge, Chernye Skaly) eruptive centers. The Sr–Nd isotope composition of the Golygin ignimbrite and some eruptive post-caldera products was investigated. The isotope variations indicate that parental magmas for all rocks of the Pauzhetka area were obtained from a weakly evolved source derived through fluid-assisted melting of a subducted slab. Geochemical data support that the formation of most magmas of the Pauzhetka caldera was mainly controlled by fractional crystallization in the lower to middle crust. MELTS-modelling agrees with geochemical data. The fractional crystallization of Kambalny basalt with 2 wt % H<sub>2</sub>O at 6 kbar provides the best fit to the observed composition of the Golygin dacite.</p></div>","PeriodicalId":20026,"journal":{"name":"Petrology","volume":null,"pages":null},"PeriodicalIF":1.0000,"publicationDate":"2022-09-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Petrology","FirstCategoryId":"89","ListUrlMain":"https://link.springer.com/article/10.1134/S0869591122050022","RegionNum":4,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 2
Abstract
The Pauzhetka Caldera (27 × 18 km) was formed in the South Kamchatka during the Golygin Ignimbrite eruption (420–440 ka), the largest known eruption in the region in the past 1 Myr. The eruption was preceded by the 3 Ma-old mafic and intermediate volcanism. After the caldera-forming eruption, a variety of products, from basalt to rhyolite, were ejected within the caldera. For understanding the origin of voluminous silicic magmatism in thin mafic South Kamchatka crust, we used geochemical and isotope data. Our research has characterized the major and trace element composition of Golygin ignimbrite, intra-caldera hydrothermally altered deposits, pre-caldera (Mt. Orlinoe Krylo, Mt. Klyuchevskaya) and post-caldera (Kambalny Ridge, Chernye Skaly) eruptive centers. The Sr–Nd isotope composition of the Golygin ignimbrite and some eruptive post-caldera products was investigated. The isotope variations indicate that parental magmas for all rocks of the Pauzhetka area were obtained from a weakly evolved source derived through fluid-assisted melting of a subducted slab. Geochemical data support that the formation of most magmas of the Pauzhetka caldera was mainly controlled by fractional crystallization in the lower to middle crust. MELTS-modelling agrees with geochemical data. The fractional crystallization of Kambalny basalt with 2 wt % H2O at 6 kbar provides the best fit to the observed composition of the Golygin dacite.
期刊介绍:
Petrology is a journal of magmatic, metamorphic, and experimental petrology, mineralogy, and geochemistry. The journal offers comprehensive information on all multidisciplinary aspects of theoretical, experimental, and applied petrology. By giving special consideration to studies on the petrography of different regions of the former Soviet Union, Petrology provides readers with a unique opportunity to refine their understanding of the geology of the vast territory of the Eurasian continent. The journal welcomes manuscripts from all countries in the English or Russian language.