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Deciphering variable mantle sources and hydrous inputs to arc magmas in Kamchatkaстатья Исследовательская статья
Статья опубликована в высокорейтинговом журнале
Информация о цитировании статьи получена из
Scopus
Статья опубликована в журнале из списка Web of Science и/или Scopus
Дата последнего поиска статьи во внешних источниках: 28 июля 2021 г.
- Авторы: Iveson Alexander A., Humphreys Madeleine C.S., Savov Ivan P., de Hoog Jan C.M., Turner Stephen J., Churikova Tatiana G., Macpherson Colin G., Mather Tamsin A., Gordeychik Boris N., Tomanikova Lubomira, Agostini Samuele, Hammond Keiji, Pyle David M., Cooper George F.
- Журнал: Earth and Planetary Sciences Letters
- Том: 562
- Год издания: 2021
- Издательство: Elsevier BV
- Местоположение издательства: Netherlands
- Первая страница: 1
- Последняя страница: 15
- Номер статьи: 116848
- DOI: 10.1016/j.epsl.2021.116848
- Аннотация: The chemistry of primitive arc rocks provides a window into compositional variability in the mantle wedge, as well as slab-derived inputs to subduction-related magmatism. However, in the long-term cycling of elements between Earth's internal and external reservoirs, a key unknown is the importance of retaining mobile elements within the subduction system, through subduction-related metasomatism of the mantle. To address these questions, we have analysed olivine-hosted melt inclusions and corresponding bulk rocks from the Kamchatka arc. Suites of melt inclusions record evidence for entrapment along melt mixing arrays during assembly of diverse parental magma compositions. Systematic variations in parental magma B/Zr, Nb/Zr, Ce/B, and δ 11 B are also apparent among the different eruptive centres studied. These element ratios constrain the nature of subduction-related metasomatism and provide evidence for ambient mantle heterogeneity and variable degrees of mantle melting.High Nb/Zr and low B/Zr in back-arc rocks indicate smaller degree melts, lower slab-derived inputs, but relatively enriched mantle compositions. Similarly, small monogenetic eruptive centres located away from the main stratocones also tend to erupt magmas with relatively lower slab contribution and overall smaller melting degrees. Conversely, arc-front compositions reflect greater slab contributions and larger degree melts of a more depleted ambient mantle. Across-arc variations in δ 11 B (ranging from ca. −6 in the rear-arc and Sredinny Ridge to +7 in the Central Kamchatka Depression) are generally consistent with variable addition of an isotopically heavy slab-derived component to a depleted MORB mantle composition. However, individual volcanic centres (e.g. Bakening volcano) show correlations between melt inclusion δ 11 B and other geochemical indicators (e.g. Cl/K 2 O, Ce/B) that require mixing between isotopically distinct melt batches that have undergone different extents of crustal evolution and degassing processes.Our results show that while melt inclusion volatile inventories are largely overprinted during shallower melt storage and aggregation, incompatible trace element ratios and B isotope compositions more faithfully trace initial mantle compositions and subduction inputs. Furthermore, we suggest that the signals of compositional heterogeneity generated in the sub-arc mantle by protracted metasomatism.
- Добавил в систему: Гордейчик Борис Николаевич
Прикрепленные файлы
| № | Имя | Описание | Имя файла | Размер | Добавлен |
|---|---|---|---|---|---|
| 1. | Полный текст | Iveson_2021.pdf | 3,1 МБ | 12 марта 2021 [gordei@mail.ru] | |
| 2. | 1-s2.0-S0012821X21001072-mmc1.docx | 1-s2.0-S0012821X21001072-mmc1.docx | 264,7 КБ | 12 марта 2021 [gordei@mail.ru] | |
| 3. | 1-s2.0-S0012821X21001072-mmc2.pdf | 1-s2.0-S0012821X21001072-mmc2.pdf | 1,4 МБ | 12 марта 2021 [gordei@mail.ru] | |
| 4. | 1-s2.0-S0012821X21001072-mmc3.xlsx | 1-s2.0-S0012821X21001072-mmc3.xlsx | 58,9 КБ | 12 марта 2021 [gordei@mail.ru] | |
| 5. | 1-s2.0-S0012821X21001072-mmc4.xlsx | 1-s2.0-S0012821X21001072-mmc4.xlsx | 24,0 КБ | 12 марта 2021 [gordei@mail.ru] |