LA-ICP-MS trace element analysis of magnetite and pyrite from the Hetaoping Fe-Zn-Pb skarn deposit in Baoshan block, SW China: Implications for ore-forming processes
LA-ICP-MS trace element analysis of magnetite and pyrite from the Hetaoping Fe-Zn-Pb skarn deposit in Baoshan block, SW China: Implications for ore-forming processes
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中国西南保山地区核桃坪铁锌铅矽卡岩矿床磁铁矿和黄铁矿的 LA-ICP-MS 微量元素分析：对成矿过程的影响
DOI：
10.1016/j.oregeorev.2020.103309
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发表时间：
2020-02
影响因子：
3.3
通讯作者：
Youwei Gu
中科院分区：
文献类型：
--
作者：
Fuchuan Chen;Jun Deng;Qingfei Wang;Jan Marten Huizenga;Gongjian Li;Youwei Gu
核桃坪存款是我国西南地区最大的铁-锌-铅矽卡岩型存款矿床之一，以上部锌-铅矿化、深部铁矿化为特征。铁矿化以磁铁矿和黄铁矿为主。磁铁矿可分为4种类型：单斜辉石-阳起石夕卡岩中的原生条带状磁铁矿（Mt-1）、石榴石夕卡岩中的原生浸染状磁铁矿（Mt-2）、单斜辉石-阳起石夕卡岩中的原生浸染状磁铁矿（Mt-3）和单斜辉石-阳起石夕卡岩中的蚀变磁铁矿（Mt-4）。黄铁矿可分为氧化矿阶段黄铁矿（Py-1）、早期硫化矿阶段黄铁矿（Py-2）和晚期硫化矿阶段黄铁矿（Py-3）。激光烧蚀-电感耦合等离子体质谱（LA-ICP-MS）的平坦时间分辨信号表明，微量元素主要以类质同象的形式存在于磁铁矿和黄铁矿中，但也有一些不相容的微量元素（如Fe_2O_3、Fe_2O_3、Fe_2O_4、Fe_2O_3、Fe_2O_4、Fe_2O_4、Fe_2O_4、Fe_2O_3）存在。磁铁矿中的Ca、K和Na以及黄铁矿中的Pb、Bi和Ag）。磁铁矿和黄铁矿中微量元素含量表明核桃坪成矿流体为岩浆成因。与斑岩型、IOCG型、Kinuna型和BIF型磁铁矿相比，核桃坪磁铁矿的Ti、V和Ni含量相对较低，而Al、Mn和Ca含量较高，具有典型的夕卡岩成因。磁铁矿中Ti浓度的变化是形成温度的指示，并表明与浸染状磁铁矿（Mt-2和Mt-3）相比，带状磁铁矿（Mt-1）在相对高温的环境中沉淀。与Mt-1和Mt-3相比，Mt-2具有较高的Si、Al和W含量以及较低的Mg和Mn含量。Mn含量从Py-1到Py-2逐渐增加，从Py-2到Py-3逐渐减少，表明流体-岩石相互作用从氧化物-矿石阶段到硫化物-矿石阶段逐渐增强，从硫化物-矿石阶段到成矿后阶段逐渐减弱。磁铁矿颗粒中V浓度的变化表明，Mt-2的氧逸度相对较高，而Mt-1和Mt-3的氧逸度相对较低，表明石榴石夕卡岩带成矿流体的氧逸度高于单斜辉石-阳起石夕卡岩带。核桃坪铁锌铅矽卡岩存款矿床的成矿空间分带可能是氧逸度变化的结果。成矿流体的温度、氧逸度以及流体-岩石相互作用的程度控制了磁铁矿和硫化物沉淀的时间顺序和空间分带性，从而导致核桃坪铁锌铅夕卡岩型存款的形成。
The Hetaoping deposit is one of the largest Fe-Zn-Pb skarn deposit in SW China, which is characterized by Zn-Pb mineralization in the upper part and the Fe mineralization in the deeper part. The Fe mineralization is dominated by magnetite and pyrite. Magnetite can be subdivided into four types: primary banded magnetite samples in clinopyroxene-actinolite skarn (Mt-1), primary disseminated magnetite in garnet skarn (Mt-2), primary disseminated magnetite in clinopyroxene-actinolite skarn (Mt-3), and altered magnetite in clinopyroxene-actinolite skarn (Mt-4). Pyrite can be subdivided into three types: pyrite in oxide-ore stage (Py-1), pyrite in early sulfide-ore stage (Py-2), and pyrite in late sulfide-ore stage (Py-3). The flat time-resolved signals of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) imply that trace elements exist mainly in the form of isomorphism in magnetite and pyrite with the exception some incompatible trace elements (e.g., Ca, K and Na in magnetite and Pb, Bi and Ag in pyrite). Trace element concentrations in magnetite and pyrite demonstrate that the ore-forming fluid in Hetaoping is of magmatic origin. Furthermore, compared to porphyry, IOCG, Kinuna and BIF type magnetite, the magnetite from Hetaoping has relatively low Ti, V and Ni concentrations but high Al, Mn and Ca concentrations, implying a typical skarn genesis. The variation of Ti concentrations in magnetite is an indication of the formation temperature and shows that banded magnetite (Mt-1) precipitated in a relatively high-temperature environment compared with disseminated magnetite (Mt-2 and Mt-3). Compared to Mt-1 and Mt-3, Mt-2 has a higher Si, Al, and W contents and a lower Mg and Mn contents. The Mn content increases from Py-1 to Py-2, and decreases from Py-2 to Py-3, suggesting that the fluid-rock interaction increased from the oxide-ore stage to the sulfide-ore stage, and decreased from sulfide-ore stage to post-ore stage. The variation of the V concentration in magnetite grains indicates a relatively higher oxygen fugacity of Mt-2 compared to Mt-1 and Mt-3, implying that the oxygen fugacity of the ore-forming fluid in the garnet skarn zone is higher than that in clinopyroxene-actinolite skarn zone. The variable oxygen fugacity probably caused spatial zoning of mineralization in Hetaoping Fe-Zn-Pb skarn deposit. The temperature and oxygen fugacity of the ore-forming fluid, and the extent of fluid-rock interaction, controlled the temporal order and spatial zonation of magnetite and sulfide precipitation, which led to the formation of the Hetaoping Fe-Zn-Pb skarn deposit.
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影响因子：
2.7
作者：
N. Cook;C. Ciobanu
通讯作者：
N. Cook;C. Ciobanu
影响因子：
5
作者：
R. Mills;H. Elderfield
通讯作者：
R. Mills;H. Elderfield
影响因子：
5.8
作者：
C. Zwahlen;Stefania Cioldi;T. Wagner;R. Rey;C. Heinrich
通讯作者：
C. Zwahlen;Stefania Cioldi;T. Wagner;R. Rey;C. Heinrich
DOI：
10.1515/9781501508561-006
发表时间：
1976-12
期刊：
--
影响因子：
--
作者：
D. Lindsley
通讯作者：
D. Lindsley
DOI：
--
发表时间：
2006
期刊：
Mineral Resources and Geology
影响因子：
--
作者：
Zhu Yu-yin
通讯作者：
Zhu Yu-yin