Английская Википедия:Crater Basalt volcanic field
Шаблон:Short description Шаблон:Coord Crater Basalt volcanic field is a volcanic field in Argentina.
The field in the Chubut province[1] covers a surface area of Шаблон:Convert and a width of Шаблон:Convert.[2] It presents nine[3] monogenetic volcanoes and several shield volcanoes that have merged to form volcanic plateaus.[4] The tallest of these cones, Antitruz 1, is Шаблон:Convert high.[2] Major cones in the field are Cerro Contreras, Cerro Fermín, Cerro Negro, Cerro Ventana, Cerro Volcán and Pinchuleu.[5] Of these Cerro Negro is the highest with Шаблон:Convert altitude.[6]
The field's products include lava and tephra.[7] In total 26 cones and 9 eruptive centres have generated Шаблон:Convert of eruption products. Volcanic cones are formed from spatter, which was still hot and liquid when falling down and fused together to form erosion-resistant spatter cones.[2] Lava flows in the area are pahoehoe that formed lava tubes, lava tumuli and "whaleback" structures.[8] They are between Шаблон:Convert thick.[5] Cerro Fermín alone is the origin of six lava flows.[6]
Being Шаблон:Convert east of the main arc[2] and beyond the edge of the Nazca Plate slab,[9] it is part of the back-arc of the Andean Southern Volcanic Zone.[7] The position next to the slab edge may be responsible for its existence.[10] The Southern Volcanic Zone is formed by the subduction of the Nazca Plate beneath the South America plate at a pace of Шаблон:Convert in the Peru-Chile Trench, Шаблон:Convert west of Crater Basalt.[5] It developed within the Шаблон:Convert wide Gastre graben that also contains salt pans.[2] This graben is part of a major fault system that extends from the Atlantic Ocean to the Pacific. Northeast of the field lies the Somuncura basaltic field of Oligocene-Miocene age and uncertain origin.[5]
It was active between 600 and 340 ka.[7] Three stages of activity have been identified, one 1 mya, the second 0.6 mya and the third 0.3 mya.[2] Activity has migrated eastward during time.[5] Other estimates indicate Holocene activity,[11] supported by stratigraphic relationships of Cerro Ventana and Cerro Contreras lava flows with nearby river sediments.[6][5] The Holocene Tagua ash (<2712–2360 BP) may originate from the Crater Basalt volcanic field but there are geographical and petrological problems with this theory.[12] There may be present-day thermal anomalies at the volcano.[13] In terms of hazard level, Crater Basalt volcanic field has been rated 35th out of 38 Argentinian volcanoes.[14]
The shield volcanoes have formed basalt as eruption products.[4] Crater Basalt basalts include basanite and trachybasalts.[5] Incompatible elements and rare-earth elements are enriched in these lavas.[8] The volcanic rocks are derived from decompression melting of the asthenosphere, with garnet and lherzolite as precursors.[7] Dunite xenoliths are found within the erupted basalts.[4]
References
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<ref>; для сносокNemethHaller2008не указан текст - ↑ 2,0 2,1 2,2 2,3 2,4 2,5 Ошибка цитирования Неверный тег
<ref>; для сносокHallerMeisterне указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокHaller2020не указан текст - ↑ 4,0 4,1 4,2 Ошибка цитирования Неверный тег
<ref>; для сносокMassaferroHaller2014не указан текст - ↑ 5,0 5,1 5,2 5,3 5,4 5,5 5,6 Ошибка цитирования Неверный тег
<ref>; для сносокMassaferroHaller2006не указан текст - ↑ 6,0 6,1 6,2 Ошибка цитирования Неверный тег
<ref>; для сносокGVPне указан текст - ↑ 7,0 7,1 7,2 7,3 Ошибка цитирования Неверный тег
<ref>; для сносокJacquesHoernle2014не указан текст - ↑ 8,0 8,1 Ошибка цитирования Неверный тег
<ref>; для сносокHaller2009не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокRosenbaumCaulfield2021не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокRosenbaum2022не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокFontijnLachowycz2014не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокWattPyle2011не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокReath2019не указан текст - ↑ Ошибка цитирования Неверный тег
<ref>; для сносокGarciaBadi2021не указан текст
