Magmatic evolution in an open and polybaric system feeding the Miocene calcalkaline lava domes of Cixerri (SW Sardinia, Italy)

IF 2.6 3区 地球科学 Q2 GEOCHEMISTRY & GEOPHYSICS
Bruna Cariddi , Vincenza Guarino , Luca Giacomo Costamagna , Massimo D’Antonio , Fred Jourdan , Vincenzo Morra , Leone Melluso
{"title":"Magmatic evolution in an open and polybaric system feeding the Miocene calcalkaline lava domes of Cixerri (SW Sardinia, Italy)","authors":"Bruna Cariddi ,&nbsp;Vincenza Guarino ,&nbsp;Luca Giacomo Costamagna ,&nbsp;Massimo D’Antonio ,&nbsp;Fred Jourdan ,&nbsp;Vincenzo Morra ,&nbsp;Leone Melluso","doi":"10.1016/j.chemer.2023.126001","DOIUrl":null,"url":null,"abstract":"<div><p><span><span>The lava domes of the Cixerri half-graben (SW Sardinia) are part of the subduction-related igneous activity that developed in Sardinia during the Upper Eocene-Middle </span>Miocene<span><span> (38–12 Ma), with calcalkaline and high-K calcalkaline affinity. The investigated rocks are porphyritic basaltic andesites<span> and andesites, with amphibole, plagioclase and minor </span></span>clinopyroxene<span> phenocrysts included in a groundmass composed of the same phases together with feldspar, quartz and opaque oxides. </span></span></span><sup>40</sup>Ar/<sup>39</sup>Ar analyses of plagioclase and amphibole separates from an andesite indicate a crystallization age of 21.31 ± 0.05 Ma. The high abundance of amphibole in the Cixerri rocks, unlike andesites from the neighboring Sardinian districts, could be explained with the high calculated oxygen fugacity (NNO+1–NNO+2) and H<sub>2</sub><span>O content (up to 9 wt%) in the Cixerri magmas<span><span>. Bulk-rock major and trace element variations, and mass balance calculations are consistent with a magma evolution mainly driven by </span>fractional crystallization of amphibole and plagioclase, which occurred in a polybaric plumbing system, as highlighted by the calculated pressure of amphibole crystallization (2–4 kbar and 6–9 kbar). Bulk rock isotope variations (</span></span><sup>87</sup>Sr/<sup>86</sup>Sr<sub>i</sub> = 0.70701–0.70786 and <sup>143</sup>Nd/<sup>144</sup>Nd<sub>i</sub><span> = 0.512328–0.512436) indicate that the magma evolution took place in open-system conditions with a low degree of crustal assimilation. The HREE flat patterns point to a magma source in the spinel stability field located in a mantle wedge depleted in incompatible elements and metasomatized by slab and sediment derived fluids and melts.</span></p></div>","PeriodicalId":55973,"journal":{"name":"Chemie Der Erde-Geochemistry","volume":"83 4","pages":"Article 126001"},"PeriodicalIF":2.6000,"publicationDate":"2023-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Chemie Der Erde-Geochemistry","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0009281923000521","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
引用次数: 0

Abstract

The lava domes of the Cixerri half-graben (SW Sardinia) are part of the subduction-related igneous activity that developed in Sardinia during the Upper Eocene-Middle Miocene (38–12 Ma), with calcalkaline and high-K calcalkaline affinity. The investigated rocks are porphyritic basaltic andesites and andesites, with amphibole, plagioclase and minor clinopyroxene phenocrysts included in a groundmass composed of the same phases together with feldspar, quartz and opaque oxides. 40Ar/39Ar analyses of plagioclase and amphibole separates from an andesite indicate a crystallization age of 21.31 ± 0.05 Ma. The high abundance of amphibole in the Cixerri rocks, unlike andesites from the neighboring Sardinian districts, could be explained with the high calculated oxygen fugacity (NNO+1–NNO+2) and H2O content (up to 9 wt%) in the Cixerri magmas. Bulk-rock major and trace element variations, and mass balance calculations are consistent with a magma evolution mainly driven by fractional crystallization of amphibole and plagioclase, which occurred in a polybaric plumbing system, as highlighted by the calculated pressure of amphibole crystallization (2–4 kbar and 6–9 kbar). Bulk rock isotope variations (87Sr/86Sri = 0.70701–0.70786 and 143Nd/144Ndi = 0.512328–0.512436) indicate that the magma evolution took place in open-system conditions with a low degree of crustal assimilation. The HREE flat patterns point to a magma source in the spinel stability field located in a mantle wedge depleted in incompatible elements and metasomatized by slab and sediment derived fluids and melts.

为 Cixerri(意大利撒丁岛西南部)中新世钙碱性熔岩穹丘提供营养的开放多巴系统中的岩浆演化过程
Cixerri 半地堑(撒丁岛西南部)的熔岩穹丘是撒丁岛在上始新世-中新世(38-12 Ma)期间形成的俯冲相关火成岩活动的一部分,具有钙碱性和高钙钾亲和性。所调查的岩石为斑状玄武安山岩和安山岩,在由相同物相与长石、石英和不透明氧化物组成的基质中含有闪石、斜长石和少量霞石表晶。从安山岩中分离出的斜长石和闪长石的 40Ar/39Ar 分析表明其结晶年龄为 21.31 ± 0.05 Ma。与邻近撒丁岛地区的安山岩不同,Cixerri岩浆中的闪石含量很高,这可以用计算出的Cixerri岩浆中氧富集度(NNO+1-NNO+2)和H2O含量(高达9 wt%)来解释。块状岩石主要元素和痕量元素的变化以及质量平衡计算都表明,岩浆的演化主要是由闪石和斜长石的分馏结晶驱动的,这种演化发生在多巴铅垂系统中,计算出的闪石结晶压力(2-4千巴和6-9千巴)突出表明了这一点。岩体同位素变化(87Sr/86Sri = 0.70701-0.70786 和 143Nd/144Ndi = 0.512328-0.512436 )表明,岩浆演化是在开放系统条件下进行的,地壳同化程度较低。HREE平面模式表明,尖晶石稳定场中的岩浆源位于不相容元素贫乏的地幔楔中,并被板块和沉积物衍生的流体和熔体所代谢。
本文章由计算机程序翻译,如有差异,请以英文原文为准。
求助全文
约1分钟内获得全文 求助全文
来源期刊
Chemie Der Erde-Geochemistry
Chemie Der Erde-Geochemistry 地学-地球化学与地球物理
CiteScore
7.10
自引率
0.00%
发文量
40
审稿时长
3.0 months
期刊介绍: GEOCHEMISTRY was founded as Chemie der Erde 1914 in Jena, and, hence, is one of the oldest journals for geochemistry-related topics. GEOCHEMISTRY (formerly Chemie der Erde / Geochemistry) publishes original research papers, short communications, reviews of selected topics, and high-class invited review articles addressed at broad geosciences audience. Publications dealing with interdisciplinary questions are particularly welcome. Young scientists are especially encouraged to submit their work. Contributions will be published exclusively in English. The journal, through very personalized consultation and its worldwide distribution, offers entry into the world of international scientific communication, and promotes interdisciplinary discussion on chemical problems in a broad spectrum of geosciences. The following topics are covered by the expertise of the members of the editorial board (see below): -cosmochemistry, meteoritics- igneous, metamorphic, and sedimentary petrology- volcanology- low & high temperature geochemistry- experimental - theoretical - field related studies- mineralogy - crystallography- environmental geosciences- archaeometry
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整,为了账户安全,请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
确定
请完成安全验证×
copy
已复制链接
快去分享给好友吧!
我知道了
右上角分享
点击右上角分享
0
联系我们:info@booksci.cn Book学术提供免费学术资源搜索服务,方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号:481959085
Book学术官方微信