Corresponding authors:Zeng Zhigang (1968-), male, Zhaodong City, Hunan Province, Professor. Research areas include submarine hydrothermal geology. E-mail:zgzeng@qdio.ac.cn
The duration of a magma chamber is of great significance for understanding the stability of the magma chamber and evaluating the active degree of active volcanoes. The element diffusion chronometry uses minerals with element concentration gradients as timers. Since the diffusion and reequilibrium process of elements in minerals conform to Fick's second law which is related to time, the time scale of the magmatic process can be defined to indicate the duration of a magma chamber. This method has been widely used in different minerals in volcanic rocks, such as Fe-Mg element diffusion in olivine and pyroxene, Mg element diffusion in plagioclase, Ti element diffusion in quartz and Li element diffusion in zircon, etc. These methods can record magma processes for only a few hours to millions of years. In the future, with the continuous development of in situ analysis and testing technology, the increase in the availability and accuracy of diffusion coefficients related to magmatism, and the improvement of the diffusion model, the development of element diffusion chronology in minerals will be greatly promoted.
Keywords:Composition zoning
;
Diffusion coefficient
;
Duration of magma chamber
Chen Zuxing, Zeng Zhigang, Wang Xiaoyuan, Yin Xuebo, Chen Shuai, Zhang Yuxiang. Duration of Magma Chamber: Progress and Prospect of Element Diffusion Chronometry of Minerals. Advances in Earth Science[J], 2020, 35(12): 1232-1242 DOI:10.11867/j.issn.1001-8166.2020.098
然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求。而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13]。当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17]。因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17]。随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程。
Fig.1
Schematic diagrams of the gradual modification of composition of the crystal zoning by diffusion[27,28]
(a) A crystal grows in equilibrium with host magma;(b) The concentration of some element along the profile shown by the thick red line across the crystal in (a); (c) This crystal is transferred to a new melt and in disequilibrium with it; (d) The evolution of the element compositional profile with time
Fig.4
Ti diffusion rate for quartz[24,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)
Fig.5
Element diffusion rate for zircon[42,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)
Fig.6
Exemplary orthopyroxene crystal in the dacite from Santorini,Greece and results for Fe-Mg diffusion timescale modeling[23]
(a) Backscattered Electron (BSE) image of the orthopyroxene with obvious Fe-Mg compositions zoning; (b) Results of diffusion timescale model using the Fe-Mg diffusion coefficients from Allan et al.[21] and Dohmen et al.[50],respectively[23]
Fig.7
Exemplary olivine crystal in the basalt from Iceland Laki volcano and results for Fe-Mg diffusion timescale modeling[18]
(a) Backscattered Electron (BSE) image of the olivine with obvious compositions zoning; (b) Upper hemisphere projections of the orientation of the electron microprobe profiles (pr) relative to crystallographic axes of the olivine crystal; (c) Results of diffusion timescale model
Constraints on the nature of the subvolcanic reservoir at South Sister volcano,Oregon from U-series dating combined with sub-crystal trace-element analysis of plagioclase and zircon
Prolonged reactions between harzburgite xenoliths and silica-undersaturated melt: Implications for dissolution and Fe-Mg interdiffusion rates of orthopyroxene
Timescales of magmatic processes during the eruptive cycle 2014-2015 at Piton de la Fournaise,La Réunion,obtained from Mg-Fe diffusion modelling in olivine
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
... 扩散距离为5~300 μm、氧逸度为石英—铁橄榄石—磁铁矿(Quartz-Fayalite-Magnetite, QFM)缓冲区以及压力为1 atmThe range of timescales that can be obtained from different elements and minerals in basalt (T=1 200 °C) and rhyolite (T=825 °C) [2]
Diffusion length scales (5~300 μm), pressure (P) at 1 atm and oxygen fugacity fO2, corresponding to the Quartz-Fayalite-Magnetite (QFM) buffer ...
Crystal size distribution systematics and the determination of magma storage times: The 1959 eruption of Kilauea volcano,Hawaii
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
... [8](b)Element diffusion rate for zircon[42,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)Fig.5
Decadal to monthly timescales of magma transfer and reservoir growth at a caldera volcano
7
2012
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Feeding andesitic eruptions with a high-speed connection from the mantle
2013
Pre-eruptive magmatic processes re-timed using a non-isothermal approach to magma chamber dynamics
2
2016
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Diffusion in solid silicates: A tool to track timescales of processes comes of age
4
2008
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Diffusion: Obstacles and opportunities in petrochronology
2017
Time scales of magmatic processes from modeling the zoning patterns of crystals
2
2008
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Diffusion coupling between trace and major elements and a model for calculation of magma residence times using plagioclase
4
2003
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Tracking timescales of short-term precursors to large basaltic fissure eruptions through Fe-Mg diffusion in olivine
8
2016
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
... (a) 具有明显成分环带的橄榄石背散射图像;(b)电子探针测试剖面(pr)相对于橄榄石晶体轴的上半球投影;(c)扩散时间尺度模型结果Exemplary olivine crystal in the basalt from Iceland Laki volcano and results for Fe-Mg diffusion timescale modeling[18]
(a) Backscattered Electron (BSE) image of the olivine with obvious compositions zoning; (b) Upper hemisphere projections of the orientation of the electron microprobe profiles (pr) relative to crystallographic axes of the olivine crystal; (c) Results of diffusion timescale model ...
Linking petrology and seismology at an active volcano
... (a) Backscattered Electron (BSE) image of the orthopyroxene with obvious Fe-Mg compositions zoning; (b) Results of diffusion timescale model using the Fe-Mg diffusion coefficients from Allan et al.[21] and Dohmen et al.[50],respectively[23] ...
Time scales of crystal residence and magma chamber volume from modelling of diffusion profiles in phenocrysts: Vesuvius 1944
2
2004
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Storage and eruption of silicic magma across the transition from dominantly effusive to caldera-forming states at an Arc Volcano (Santorini,Greece)
15
2017
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
(a) Backscattered Electron (BSE) image of the orthopyroxene with obvious Fe-Mg compositions zoning; (b) Results of diffusion timescale model using the Fe-Mg diffusion coefficients from Allan et al.[21] and Dohmen et al.[50],respectively[23] ...
... (a) Backscattered Electron (BSE) image of the orthopyroxene with obvious Fe-Mg compositions zoning; (b) Results of diffusion timescale model using the Fe-Mg diffusion coefficients from Allan et al.[21] and Dohmen et al.[50],respectively[23] ...
... (a) 具有明显成分环带特征的斜长石背散射图像;(b~c)扩散时间尺度模型结果Exemplary plagioclase crystal in the volcanic rock from Santorini Island and results for Mg diffusion timescale modeling[23]
(a) Backscattered Electron (BSE) image of the plagioclase with obvious compositions zoning; (b~c) Results of diffusion timescale model ...
New Ti-in-quartz diffusivities reconcile natural Ti zoning with time scales and temperatures of upper crustal magma reservoirs
9
2020
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
... [24,38] (a)与不同方法约束的美国加利福尼亚州Bishop凝灰岩岩浆演化时间尺度[24](b)Ti diffusion rate for quartz[24,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)Fig.43.2 锆石Li元素扩散计时
... [24](b)Ti diffusion rate for quartz[24,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)Fig.43.2 锆石Li元素扩散计时
... [24,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)Fig.43.2 锆石Li元素扩散计时
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
Reconciling Li and O diffusion in zircon with protracted magmatic crystal residence
6
2019
... 然而,对于持续时间尺度小于几百年的岩浆房,传统放射性同位素定年方法的分辨率难以达到精度要求.而元素扩散计时法,精度可以达到小时级别,近年来得到广泛重视[11~13].当矿物经历岩浆混合作用而处于不平衡状态时,矿物中的元素会发生扩散再平衡,扩散符合菲克第二定律(Fick's second law),与时间有关,从而可以用于定年[14~16],且发生扩散的速率很大程度上取决于温度,当岩浆喷发后,温度降低、扩散停止[2,17].因此,该方法可以用来估算岩浆从混合到喷发的时间,指示岩浆最小滞留时间[2,17].随着元素扩散系数的实验和理论约束越来越精确和完善,该方法目前已成功应用于不同的火山岩斑晶矿物,如橄榄石和辉石Fe-Mg元素扩散[18~22]、斜长石Mg元素扩散[11,17,23]、石英Ti元素扩散[24,25]以及锆石Li元素扩散[8,26]等,可以记录持续仅数小时至数百万年的岩浆过程. ...
... (a)晶体与其寄主熔体平衡生长;(b)沿(a)中晶体上的粗红线所示轮廓的某元素浓度;(c)该晶体进入新的熔体中,处于非平衡状态;(d)成分环带随时间的演变Schematic diagrams of the gradual modification of composition of the crystal zoning by diffusion[27,28]
(a) A crystal grows in equilibrium with host magma;(b) The concentration of some element along the profile shown by the thick red line across the crystal in (a); (c) This crystal is transferred to a new melt and in disequilibrium with it; (d) The evolution of the element compositional profile with time ...
... (a)晶体与其寄主熔体平衡生长;(b)沿(a)中晶体上的粗红线所示轮廓的某元素浓度;(c)该晶体进入新的熔体中,处于非平衡状态;(d)成分环带随时间的演变Schematic diagrams of the gradual modification of composition of the crystal zoning by diffusion[27,28]
(a) A crystal grows in equilibrium with host magma;(b) The concentration of some element along the profile shown by the thick red line across the crystal in (a); (c) This crystal is transferred to a new melt and in disequilibrium with it; (d) The evolution of the element compositional profile with time ...
... ,38] (a)与不同方法约束的美国加利福尼亚州Bishop凝灰岩岩浆演化时间尺度[24](b)Ti diffusion rate for quartz[24,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)Fig.43.2 锆石Li元素扩散计时
... ,38](a) and time scales of magmatic evolution for the Bishop Tuff (California,USA),constrained by various modeling methods[24](b)Fig.43.2 锆石Li元素扩散计时
... [42,43](a)与新西兰塔拉威拉火山群中的流纹岩中锆石U-Th年龄、Li元素浓度梯度及扩散模拟[8](b)Element diffusion rate for zircon[42,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)Fig.5
... [42,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)Fig.5
Element diffusion rate for zircon[42,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)Fig.5
... ,43](a) and U-Th age,Li element concentration gradient and diffusion simulation of zircon in rhyolite in Tarawera volcanic group from New Zealand[8](b)Fig.5
Prolonged reactions between harzburgite xenoliths and silica-undersaturated melt: Implications for dissolution and Fe-Mg interdiffusion rates of orthopyroxene
... (a) Backscattered Electron (BSE) image of the orthopyroxene with obvious Fe-Mg compositions zoning; (b) Results of diffusion timescale model using the Fe-Mg diffusion coefficients from Allan et al.[21] and Dohmen et al.[50],respectively[23] ...
Fe-Mg diffusion in olivine I: Experimental determination between 700 and 1,200°C as a function of composition,crystal orientation and oxygen fugacity
Timescales of magmatic processes during the eruptive cycle 2014-2015 at Piton de la Fournaise,La Réunion,obtained from Mg-Fe diffusion modelling in olivine