Zircon as a recorder of contrasting magma recharge and eruptive recurrence patterns
Zircon as a recorder of contrasting magma recharge and eruptive recurrence patterns
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DOI：
10.1016/j.epsl.2021.117104
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发表时间：
2021-07-23
影响因子：
5.3
通讯作者：
Atici, Gokhan
中科院分区：
文献类型：
--
作者：
Friedrichs, Bjarne;Schmitt, Axel K.;Atici, Gokhan
晚更新世-全新世喷发行为对比观察。Hasan和Mt.位于土耳其安纳托利亚中部的两个相邻的层状火山复合体Erciyes提出了关于活火山背后岩浆系统的大小和性质的一般性问题。在这里，我们补充了来自这些火山的>；1000晶体的U-Th-Pb锆石边缘和内部结晶年龄，并在相同的地点进行了微量元素分析，以揭示它们的岩浆史。锆石结晶的热化学模拟被用来定量对比岩浆的补给和储存方式。Hasan和Mt.Erciyes的特点是自中更新世以来持续的岩浆和火山活动，这从单个晶体和晶体群体中可以明显看出。然而，锆石记录了两个系统相反的热化学演化：mt。哈桑在整个晚更新世都有反复喷发的历史，在过去的300ka左右，钛在锆石中的结晶温度和分异指数(如Zr/Hf比值)和Eu异常(Eu/Eu*)的范围相对较窄。相反，这些参数在更宽的范围内波动。Erciyes，在大约105-85年和大约9ka的两个主要喷发活动阶段，相对原始的锆石内部成核，而在这两个主要喷发活动阶段之间，锆石边缘演化为更具差异性的成分。对比的锆石记录被解释为反映了山体长期的热化学稳定状态。哈山岩浆系统，但山体条件起伏不定。由于充电率的变化，Erciyes。模拟的锆石年龄为1-0.5 km(3)/ka。哈山，但仅与0.1公里(3)/卡相似。Erciyes，指示山体在喷发条件下的“热”岩浆储存。哈山，但“冷”的岩浆储存温度低于山体的流变闭锁温度。埃尔西耶斯。山的体积较小。Erciyes地下管道系统与其更大的建筑物体积形成了对比，这表明火山已经到了一个逐渐减弱的阶段，在这个阶段，间歇性增强的岩浆补充可能会引发猛烈的喷发。全新世早期山体的复活。Erciyes可能是对冰川卸荷的响应，而高峰期则是Mt.由于大量岩浆储集层的热缓冲作用，哈山系统可能对岩浆补给的变化反应较差。(C)2021年爱思唯尔B.V.保留所有权利。
Contrasting Late Pleistocene-Holocene eruptive behavior observed for Mt. Hasan and Mt. Erciyes, two neighboring stratovolcanic complexes in Central Anatolia, Turkey, poses general questions on the size and nature of magma systems underlying active volcanoes. Here, we complement U-Th-Pb zircon rim and interior crystallization ages for >1000 crystals from these volcanoes with trace element analyses on the same spots to unravel their magmatic histories. Thermochemical modeling of zircon crystallization is applied to quantify contrasting magma recharge and storage regimes.Both Mt. Hasan and Mt. Erciyes are characterized by protracted magmatic and volcanic activity since the Middle Pleistocene that is evident from individual crystals and crystal populations. However, zircon records contrasting thermochemical evolutions for both systems: Mt. Hasan with a history of recurrent eruptions throughout the Late Pleistocene exhibits comparatively narrow ranges of Ti-in-zircon crystallization temperatures and differentiation indices such as Zr/Hf ratios as well as Eu anomalies (Eu/Eu*) over the last ca. 300 ka. On the contrary, these parameters fluctuate over broader ranges for Mt. Erciyes, where relatively primitive zircon interiors nucleated during two major eruptive activity phases at ca. 105-85 and ca. 9 ka, whereas zircon rims evolved to more differentiated compositions during the protracted eruptive lull in between.The contrasting zircon record is interpreted to mirror a protracted thermochemical steady-state of the Mt. Hasan magma system, but fluctuating conditions in Mt. Erciyes due to recharge rate variations. Zircon ages are modeled with integrated magma recharge rates of similar to 1-0.5km(3)/ka for Mt. Hasan, but only similar to 0.1km(3)/ ka for Mt. Erciyes, indicating "warm" magma storage under eruptible conditions for Mt. Hasan, but "cold" magma storage below the rheological lockup temperature for Mt. Erciyes. The smaller volume of the Mt. Erciyes subsurface plumbing system contrasts with its larger edifice volume, suggesting that the volcano has reached a waning stage where episodically intensified magma recharge can trigger violent eruptions. The early Holocene resurgence of Mt. Erciyes may be in response to glacial unloading, whereas the peak-stage Mt. Hasan system may be less responsive to changes in magma recharge due to thermal buffering by a voluminous magma reservoir. (C) 2021 Elsevier B.V. All rights reserved.