Nikogosian I K, Bracco Gartner A J J, van Bergen M J, Mason P R D, van Hinsbergen D J J
Department of Earth Sciences Vrije Universiteit Amsterdam Amsterdam The Netherlands.
Department of Earth Sciences Utrecht University Utrecht The Netherlands.
Tectonics. 2018 Dec;37(12):4535-4566. doi: 10.1029/2018TC005219. Epub 2018 Dec 15.
We present an extensive study of rehomogenized olivine-hosted melt inclusions, olivine phenocrysts, and chromian spinel inclusions to explore the link between geodynamic conditions and the origin and composition of Pliocene-Quaternary intraplate magmatism in Anatolia at Kula, Ceyhan-Osmaniye, and Karacadağ. Exceptional compositional variability of these products reveals early and incomplete mixing of distinct parental melts in each volcanic center, reflecting asthenospheric and lithospheric mantle sources. The studied primitive magmas consist of (1) two variably enriched ocean island basalt (OIB)-type melts in Kula; (2) both OIB-type and plume mid-ocean ridge basalt (P-MORB)-like melts beneath Toprakkale and Üçtepeler (Ceyhan-Osmaniye); and (3) two variably enriched OIB-type melts beneath Karacadağ. Estimated conditions of primary melt generation are 23-9 kbar, 75-30 km, and 1415-1215 °C for Kula; 28-19 kbar, 90-65 km, and 1430-1350 °C for Toprakkale; 23-18 kbar, 75-60 km, and 1400-1355 °C for Üçtepeler; and 35-27 kbar, 115-90 km, and 1530-1455 °C for Karacadağ, the deepest levels of which correspond to the depth of the lithosphere-asthenosphere boundary in all regions. Although magma ascent was likely facilitated by local deformation structures, recent Anatolian intraplate magmatism seems to be triggered by large-scale mantle flow that also affects the wider Arabian and North African regions. We infer that these volcanics form part of a much wider Arabian-North African intraplate volcanic province, which was able to invade the Anatolian upper plate through slab gaps.
我们对重新均质化的橄榄石寄主熔体包裹体、橄榄石斑晶和铬尖晶石包裹体进行了广泛研究,以探讨地球动力学条件与安纳托利亚库拉、杰伊汉-奥斯曼尼耶和卡拉卡达格地区上新世-第四纪板内岩浆作用的起源和成分之间的联系。这些产物异常的成分变化揭示了每个火山中心不同母岩浆的早期和不完全混合,反映了软流圈和岩石圈地幔源。所研究的原始岩浆包括:(1)库拉地区两种不同程度富集的大洋岛玄武岩(OIB)型熔体;(2)托普拉克卡莱和于塞泰佩勒(杰伊汉-奥斯曼尼耶)之下的OIB型熔体和类似地幔柱大洋中脊玄武岩(P-MORB)的熔体;(3)卡拉卡达格之下两种不同程度富集的OIB型熔体。库拉地区原生熔体生成的估计条件为23 - 9千巴、75 - 30千米和1415 - 1215℃;托普拉克卡莱为28 - 19千巴、90 - 65千米和1430 - 1350℃;于塞泰佩勒为23 - 18千巴、75 - 60千米和1400 - 1355℃;卡拉卡达格为35 - 27千巴、115 - 90千米和1530 - 1455℃,其中最深的深度对应于所有地区岩石圈-软流圈边界的深度。尽管岩浆上升可能受到局部变形构造的促进,但近期安纳托利亚板内岩浆作用似乎是由大规模地幔流触发的,这种地幔流也影响更广泛的阿拉伯和北非地区。我们推断,这些火山岩是一个更广泛的阿拉伯-北非板内火山省的一部分,该火山省能够通过板块间隙侵入安纳托利亚上覆板块。