Transition to magma-driven rifting in the South Turkana Basin, Kenya: Part 2
Transition to magma-driven rifting in the South Turkana Basin, Kenya: Part 2
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肯尼亚南图尔卡纳盆地向岩浆驱动裂谷的转变：第 2 部分
DOI：
10.1144/jgs2021-160
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发表时间：
2022
影响因子：
2.7
通讯作者：
Karson, Jeffery A.
中科院分区：
文献类型：
--
作者：
Rooney, Tyrone O.;Wallace, Paul J.;Muirhead, James D.;Chiasera, Brandon;Steiner, R. Alex;Girard, Guillaume;Karson, Jeffery A.
应变局部化是大陆裂陷和海底扩张之间过渡的核心。在东非裂谷系统（EARS），有一个新兴的理解之间的联系伸展脉冲和岩浆事件。我们研究了图尔卡纳凹陷内的现代岩浆活动及其与伸展应变分布的关系。我们利用大块岩石、熔融包裹体和橄榄石地球化学数据探讨了南岛火山岩浆作用的来源，发现岩浆来自岩石圈以下的来源，相当于裂谷较成熟部分的岩浆作用。的深度范围的岩浆管道系统的南岛的限制使用蒸汽饱和压力来自气泡校正的H2O和CO2浓度的熔融包裹体和结果表明，类似于现代轴向火山系统的EARS的其他部分观察到的岩浆系统。南岛所代表的集中轴向岩浆活动带与集中轴向断层区域同时演化，该区域容纳了该纬度大部分区域全新世伸展和沉降。我们的结论是，在南岛，沿着EARS的这一部分，岩浆和构造应变向现代集中侵入区迁移。补充材料：S1-S2图像文件、数据表文件S3-S6和标题文件S7可在https://doi.org/10.6084/m9.figshare.c.6026627上获得
Strain localization is central to the transition between continental rifting and seafloor spreading. In the East African Rift System (EARS), there is an emerging understanding of the link between extensional pulses and magmatic episodes. We investigate modern magmatism located within the Turkana Depression and its relationship with the distribution of extensional strain. We probe the source of magmatism at South Island volcano using bulk rock, melt inclusion and olivine geochemical data and find that the magmas are derived from sub-lithospheric sources equivalent to magmatism in the more mature sectors of the rift. The depth extent of the magmatic plumbing system of South Island is constrained using vapour saturation pressures derived from bubble-corrected H2O and CO2concentrations in melt inclusions and the results indicate a magmatic system resembling modern axial volcanic systems observed in other parts of the EARS. The zone of focused axial magmatism that South Island represents has evolved contemporaneously with a region of focused axial faulting that has accommodated the majority of regional Holocene extension and subsidence at this latitude. We conclude that at South Island there has been a migration of magmatic and tectonic strain towards the modern zone of focused intrusion along this portion of the EARS.Supplementary material:S1–S2 image files, data table files S3–S6 and caption file S7 are available at https://doi.org/10.6084/m9.figshare.c.6026627