Tourmaline as a recorder of magmatic–hydrothermal evolution: an in situ major and trace element analysis of tourmaline from the Qitianling batholith, South China
Tourmaline as a recorder of magmatic–hydrothermal evolution: an in situ major and trace element analysis of tourmaline from the Qitianling batholith, South China
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电气石作为岩浆热液演化的记录者：华南骑田岭岩基电气石的原位常量和微量元素分析
DOI：
10.1007/s00410-015-1195-7
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发表时间：
2015-10
影响因子：
3.5
通讯作者：
Tao Yang
中科院分区：
文献类型：
--
作者：
Shui-Yuan Yang;Shao-Yong Jiang;Kui-Dong Zhao;Bao-Zhang Dai;Tao Yang
在祁天岭花岗岩基中发现了4种类型的电气石：花岗岩固结早期的自形浸染型电气石（DT型）；典型的间质结节型电气石（NT型）形成于结晶史晚期；热液成因的放射状碧玺脉入口（RT型）和脉状碧玺（VT型）。我们用原位电子探针和激光烧蚀电感耦合等离子体质谱对这四种碧玺进行了主量元素和微量元素的分析。这些电气石在成分上可分为碱系和榴石固溶体系。vt型电气石中微量元素与主量元素具有明显的相关性，可能与电气石析出的热液中这些元素的共变有关。花岗岩碧玺REE丰度低，LREE负趋势，Eu正异常，HREE低于或接近检出限。dt型电气石呈现正Eu异常，这可能是由于Eu2+优先于Eu3+的结合。nt型电气石的稀土耗竭可能反映了富稀土矿物的共结晶。nt型电气石中的Eu正异常是由电气石取代早期长石导致的Eu2+后期释放所致。脉状电气石（RT型和VT型）从La到Nd表现出相似的斜率，未见Eu异常。矿脉碧玺中球粒陨石归一化的稀土元素模式呈凹向上、mree亏缺模式，Ho处的最小值向Lu稳步上升，可能反映了沉淀介质的稀土元素特征。热液中稀土元素的富集可归因于内部流体演化过程中稀土-氟化物络合物的形成。
Four types of tourmaline in the Qitianling granitic batholith, South China, were identified in this study: euhedral disseminated tourmaline (DT type) in the early stage of granite consolidation; typical interstitial nodular tourmaline (NT type) formed late in the crystallization history; radial tourmaline veinlet (RT type) and vein tourmaline (VT type) of hydrothermal origin. We performed major and trace element analysis by in situ electron microprobe and laser ablation inductively coupled plasma mass spectrometry on these four tourmaline types. Compositionally, these tourmalines fall into the alkali group and schorl–dravite solid solution series. There is clear correlation between trace and major elements in VT-type tourmalines, likely related to co-variations of these elements in the hydrothermal fluid from which the tourmaline precipitated. Tourmaline from granites displays low REE abundances and negative LREE trends, positive Eu anomalies, and HREE below or close to their detection limits. The DT-type tourmalines show a positive Eu anomaly, which is probably due to a preferential incorporation of Eu2+over Eu3+. REE depletion in NT-type tourmalines may reflect co-crystallization of REE-rich minerals. The positive Eu anomaly in NT-type tourmalines is due to late-stage release of Eu2+caused by tourmaline replacement of early feldspar. Vein tourmalines (RT and VT type) display similar slopes from La to Nd, without an Eu anomaly. The chondrite-normalized REE patterns in tourmalines from veins display a concave upward-shaped, MREE-depleted pattern, with minimum values at Ho increasing steadily to Lu, and may reflect the REE characteristics of the precipitated medium. HREE enrichment in hydrothermal fluid can be attributed to the formation of REE-fluoride complexes during the internal fluid evolution.
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影响因子：
3.9
作者：
R. Trumbull;M. Chaussidon
通讯作者：
R. Trumbull;M. Chaussidon
影响因子：
1.8
作者：
Zhu Jin
通讯作者：
Zhu Jin
影响因子：
3.9
作者：
M. Marks;H. Marschall;P. Schühle;A. Guth;T. Wenzel;Dorrit E. Jacob-;M. Barth;G. Markl
通讯作者：
M. Marks;H. Marschall;P. Schühle;A. Guth;T. Wenzel;Dorrit E. Jacob-;M. Barth;G. Markl
影响因子：
3.3
作者：
Jianye Yang;Lei Zhao;Weiguo Zhang
通讯作者：
Jianye Yang;Lei Zhao;Weiguo Zhang
影响因子：
0.9
作者：
Kristen Michelle Longfellow;S. E. Swanson
通讯作者：
Kristen Michelle Longfellow;S. E. Swanson