Geochemistry and Crystallization Conditions of Magmas Related to Porphyry Mo Mineralization in Northeastern China

2020 ◽  
Vol 115 (1) ◽  
pp. 79-100 ◽  
Author(s):  
Hegen Ouyang ◽  
Jingwen Mao ◽  
Ruizhong Hu
Keyword(s):  
Inductively Coupled Plasma ◽  
Melt Inclusions ◽  
Northeastern China ◽  
Silicate Melts ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Crystallization Conditions ◽  
Porphyry Mo Deposit ◽  
The One ◽  
Porphyry Mo Deposits

Abstract To better understand processes leading to porphyry Mo deposit formation, the metal content, volatile content, and crystallization conditions of melt inclusions from pre- and synmineralization intrusions in six porphyry(-skarn) Mo deposits of northeastern China (Aolunhua, Hashitu, Lanjiagou, Songbei, Wanbaoyuan, and Yangjiazhangzi) were investigated by means of laser ablation-inductively coupled plasma-mass spectrometry and electron microprobe analysis. The ore-forming silicate melts were one to four times more evolved than average granite with 1 to 7 ppm Mo. The ore-related intrusions crystallized predominantly at 760° to 690°C and 3.7 to 1.0 kbar, except for the one at Hashitu, which crystallized at 770° to 740°C and lower pressures (2.0–1.0 kbar). Fertile silicate melts at Hashitu contain up to 0.4 wt % F, 0.03 to 0.09 wt % Cl, 5.0 to 7.0 wt % H2O, 10 to 24 ppm Cs, and 200 to 500 ppm Rb, whereas those at Yangjiazhangzi and Wanbaoyuan contain less Cs (3–6 ppm and 5–7 ppm, respectively), less Rb (180–220 ppm and 200–240 ppm, respectively), and negligible F (<0.15 wt %) but have similar Cl (0.03–0.05 wt %) and H2O (5.3–6.5 wt % and 4.0–5.2 wt %, respectively) contents. Calculated melt viscosities in fertile magmas (log η = 4.3–6.1 Pa s) are at the lower end of the values reported for felsic melts at the same temperature. Comparison between syn- and premineralization intrusions in individual deposits reveals that the ore-related intrusions were similarly evolved and had similar Mo contents and crystallization conditions as the nonmineralizing intrusions. The only difference is that the premineralization intrusions tend to occur as batholiths. The key to porphyry Mo mineralization lies in the focusing of fluid into and through a small rock volume on the top of the intrusion. For the studied porphyry Mo deposits, the mineralizing magmas are all Mo poor, indicating Mo enrichment is not required to form porphyry Mo deposits. Metal endowments in porphyry Mo deposits have no direct relationship with the composition and crystallization condition of mineralizing melts but are linked with the fluid flux released from the underlying magma chamber through a cupola.

CONTROLS ON THE METAL ENDOWMENT OF PORPHYRY Mo DEPOSITS: INSIGHTS FROM THE LUMING PORPHYRY Mo DEPOSIT, NORTHEASTERN CHINA

2021 ◽  
Author(s):  
Hegen Ouyang ◽  
Jingwen Mao ◽  
Ruizhong Hu ◽  
John Caulfield ◽  
Zhenhua Zhou
Keyword(s):  
Inductively Coupled Plasma ◽  
Intrusive Complex ◽  
Weighted Mean ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Multiple Pulses ◽  
Porphyry Mo Deposit ◽  
Intrusive Suite ◽  
Porphyry Mo Deposits

Abstract Processes controlling the metal endowment of arc-related porphyry Mo deposits are not well understood. Located in northeastern China, the arc-related Luming porphyry Mo deposit has a proven reserve of 0.75 Mt Mo at an average grade of 0.092 wt % and is characterized by multiple pulses of alteration and mineralization. These features make this deposit an ideal location to investigate the role of multiple pulses of magmatism and fluid release in the evolution and formation of an arc-related porphyry Mo deposit. Molybdenum mineralization at Luming is typically observed as a series of molybdenite-bearing veins hosted within a composite intrusive complex, referred to as the Luming Intrusive Suite. Crosscutting relationships between intrusive units and off-set veins indicate that the Luming Intrusive Suite is composed of five major, successive granitic intrusions: the premineralization plutonic biotite monzogranite and monzogranite units, and the synmineralization stock- and dike-like porphyritic monzogranite, granite porphyry, and syenogranite units. Each synmineralization unit is associated with similar vein sequences that comply with the general form of early EB-type biotite veins, through A-type quartz ± biotite and B-type quartz-molybdenite veins, to late D-type quartz-molybdenite ± pyrite ± chalcopyrite, molybdenite, quartz-pyrite ± calcite, and calcite ± clays veins. The intensity and volume of alteration and mineralization within a given synmineralization unit decrease from early- through inter- to late-mineralization units. Although minor Mo mineralization is associated with potassic alteration along B-type veins, the majority of the ore is associated with D-type quartz-molybdenite-pyrite and molybdenite veins rimmed by sericite-chlorite-pyrite alteration, which are primarily hosted in the two premineralization units. A combination of laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) zircon U-Pb and hydrothermal biotite 40Ar/39Ar studies, together with available isotope dilution-inductively coupled plasma-mass spectrometry (ID-ICP-MS) molybdenite Re-Os data, has resulted in a substantial reappraisal of the timing of magmatism and its association with molybdenite mineralization at Luming. The volumetrically dominant premineralization intrusive units have indistinguishable zircon U-Pb weighted mean 206Pb/238U ages ranging from 187.5 ± 2.8 to 186.5 ± 3.6 Ma (2σ), whereas the synmineralization units yield weighted mean 206Pb/238U ages from 178.6 ± 2.2 to 175.6 ± 3.0 Ma (2σ). The zircon U-Pb weighted mean 206Pb/238U ages of the synmineralization units are indistinguishable from the mean molybdenite Re-Os model (178.1 ± 2.7; 2σ) and hydrothermal biotite 40Ar/39Ar plateau (174.7 ± 1.1 Ma; 2σ) ages within uncertainty, confirming a genetic link with mineralization. Melt inclusion data show that the synmineralization intrusions were Mo poor, with Mo concentrations <4 ppm. The data presented here suggest that molybdenite mineralization at Luming was most likely accomplished through three discrete magmatic-hydrothermal events during assembly of the Mo-poor synmineralization intrusive complex. The giant Luming deposit appears to be related to multiple pulses of magmatic-hydrothermal activities, resulting in the superposition of temporally distinct mineralization events. Our results suggest that pulsed release of ore-forming magmas and fluids, which are channeled along focusing structures like small porphyry fingers within a focused area, from a large magma chamber at depth may play a major role in the formation of large to giant porphyry Mo deposits of both the arc-related and Climax types. This conclusion is in line with field observations of a number of large to giant porphyry Mo deposits, which commonly show reversals in magmatic-hydrothermal evolutionary trend and are associated with multiple pulses of small stocks and dikes that are separate in time and space.

scholarly journals Study on the Behavior and Removal of Cadmium and Zinc Using Taraxacum officinale and Gazania under the Application of Biodegradable Chelating Agents

2021 ◽  
Vol 11 (4) ◽  
pp. 1557
Author(s):  
Naoki Kano ◽  
Takumi Hori ◽  
Haixin Zhang ◽  
Naoto Miyamoto ◽  
David Eva Vanessa Anak ◽  
...  
Keyword(s):  
Inductively Coupled Plasma ◽  
Chelating Agents ◽  
Environmental Control ◽  
Chelating Agent ◽  
Taraxacum Officinale ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Plasma Mass Spectrometry ◽  
Experimental Treatments ◽  
The One

The removal of cadmium (Cd) and zinc (Zn) from soil by phytoremediation was investigated using Taraxacum officinale and Gazania. A plant environmental control system was used to cultivate the plants. The effects of different biodegradable chelating agents (i.e., EDDS, HIDS, and GLDA), relative humidity, and other competitive metals on the adsorption of Cd and Zn were also studied. In addition, the approach for metal recovery was explored by extraction of metals from plants after phytoremediation using Gazania. The concentrations of Cd and Zn were determined by inductively coupled plasma mass spectrometry (ICP-MS). In addition, one-way analysis of variance (ANOVA) tests were performed.to determine significant differences between the experimental treatments adopted in this work. Consequently, the following main conclusions were obtained: (1) In the case of Taraxacum officinale, Cd and Zn could be removed even under the presence of other heavy metals. (2) By adding a chelating agent, the amount absorbed by the shoot generally increased. (3) In the case of Gazania, the concentration of Cd was higher in root than that in shoot, whereas the concentration of Zn was higher in the shoot than that in the root. (4) Taraxacum officinale was more suitable for phytoremediation of Cd than Gazania. (5) Cd and Zn could be extracted from plants by adding a low concentration of nitric acid. (6) The one-way ANOVA tests showed no statistically significant differences among the experimental treatments.

Fluid compositions reveal fluid nature, metal deposition mechanisms, and mineralization potential: An example at the Haobugao Zn-Pb skarn, China

Geology ◽  
2020 ◽  
Author(s):  
Qihai Shu ◽  
Zhaoshan Chang ◽  
John Mavrogenes
Keyword(s):  
Inductively Coupled Plasma ◽  
Isotope Composition ◽  
Northeastern China ◽  
Metal Deposition ◽  
Mass Balance Calculation ◽  
Inductively Coupled ◽  
Mineralization Potential ◽  
Plasma Mass Spectrometry ◽  
Absolute Concentrations ◽  
Potential Tool

Fluid inclusion compositions obtained from laser ablation–inductively coupled plasma–mass spectrometry at the Haobugao Zn-Pb skarn in northeastern China provide constraints on fluid origin, evolution, and metal deposition mechanisms and an example of evaluating mineralization potential. Metal concentrations in the prograde fluids were high (up to 1.4 wt% Zn and 1.8 wt% Pb) but remained in solution, likely due to the high temperatures (440–575 °C) and salinities (35.4–45.3 wt% NaCl equivalent). Absolute concentrations of elements (e.g., Rb and Na) and mass ratios (e.g., Zn/Na and K/Na) reveal that the early, prograde fluids were magmatic, consistent with the oxygen isotope composition of fluids (δ18OH2O = 5.5‰–8.5‰). Later mixing with a meteoric fluid caused dilution and Zn-Pb deposition, as revealed by lowered element concentrations and Pb/(Na + K) and Zn/(Na + K) ratios in the sulfide-stage fluid inclusions. Elevated Ca/K ratios in sphalerite-hosted inclusions indicate fluid-carbonate reactions that buffered fluid pH, also facilitating Zn-Pb precipitation. Although cassiterite and molybdenite occur locally at Haobugao, mass balance calculation shows low metal endowment (maximum 2900 t Sn and 2200 t Mo) of the system. Furthermore, the generally unchanged Sn/(Na + K) and Mo/(Na + K) ratios from pre- to late-mineralization fluids suggest that the fluids were never saturated in Sn and Mo. Therefore, finding much Sn or Mo at Haobugao is unlikely. This demonstrates a potential tool for evaluating the metal endowment of a mineral prospect, which may guide exploration.

scholarly journals Capabilities and limitations of gel electrophoresis for elemental speciation: A laboratory's experience

2006 ◽  
Vol 78 (1) ◽  
pp. 91-103 ◽  
Author(s):  
Cyrille C. Chéry ◽  
Luc Moens ◽  
Rita Cornelis ◽  
Frank Vanhaecke
Keyword(s):  
Gel Electrophoresis ◽  
Inductively Coupled Plasma ◽  
Practical Experience ◽  
Electrothermal Vaporization ◽  
Detection Techniques ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Powerful Approach ◽  
Plasma Mass Spectrometry ◽  
The One

Gel electrophoresis is a fractionation/separation technique that yields valuable information in the field of metalloproteomics, often referred to as metallomics. This paper is based on four years of practical experience of the authors' lab in this domain and highlights the capabilities and limitations of gel electrophoresis. Pitfalls of the technique were recognized by identifying the origin of artefacts in the separation, species degradation being the most important. Gel electrophoresis can be accomplished under either native or denaturing conditions. The speciation of vanadium and selenium among serum and yeast proteins, respectively, is used to illustrate these two major modes. The most powerful approach is two-dimensional denaturing gel electrophoresis. This review of the methods used in our laboratory also describes the application of the two major detection techniques, autoradiography on the one hand and electrothermal vaporization - or laser ablation (LA) - inductively coupled plasma-mass spectrometry (ICP-MS) on the other.

scholarly journals Metal Threads from the Fourteenth-Century Slabbed Graves at the Plateau of Eski-Kermen

2021 ◽  
pp. 229-245
Author(s):  
Anna V. Antipenko ◽  
Anastasia Yu. Loboda ◽  
Elzara A. Khairedinova ◽  
Artem M. Ismagulov ◽  
Ekaterina S. Vashchenkova ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Fourteenth Century ◽  
Inductively Coupled Plasma ◽  
High Grade ◽  
Inductively Coupled ◽  
Inner Surface ◽  
Plasma Mass Spectrometry ◽  
The One ◽  
Scanning Electron ◽  
Thin Band

This paper presents the results of the study of metal threads found in the fourteenth-century burials in slabbed graves located atop of the plateau of Eski-Kermen. The inductively coupled plasma mass spectrometry determined the metal of the threads in question as high-grade silver. The results of scanning electron microscopy of the surface morphology of the artefacts allowed the one to suggest a variant of reconstruction of the sequence of technological operations in the manufacture of the metal threads in question. The feature of all the metal threads under study is very even outer and inner surface and stable thickness and width of the metal band. In all cases, gold inclusions were stretched in the mass of metal along the long edge of the bands. Cast metal was flattened into a thin band. Parallel scratches along the butt end of the threads suggest that rolled out metal was cut with a tool with a thin, sharp blade leaving scratches along the course of the blade. Semi-finished products were wound onto an organic core. The threads found in the slabbed graves atop of the plateau of Eski-Kermen were spun silver threads wound onto a silk core. Technologically, these threads correspond to the products of Mediterranean workshops. The location of the metal threads in the burial indicates that they were used in the embroidering of the collar and neck.

Optical and Chemical Study of Quartz from Granitic Pegmatites

2018 ◽  
Vol 69 (7) ◽  
pp. 1846-1850
Author(s):  
Delia Anne Marie Androne ◽  
Dana Ortansa Dorohoi ◽  
Dan Gheorghe Dimitriu ◽  
Haino Uwe Kasper
Keyword(s):  
Inductively Coupled Plasma ◽  
Chemical Study ◽  
Linear Birefringence ◽  
Granitic Pegmatites ◽  
Inductively Coupled ◽  
Fine Grained ◽  
Icp Ms ◽  
High Participation ◽  
Plasma Mass Spectrometry ◽  
Crystallization Conditions

Of the nine quartz samples collected from the Contu - Negovanu granitic pegmatites (Southern Carpathians, Romania), three were separated under binocular lenses and turned into fine grained powders, for X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) investigation techniques, whilst the other six samples were prepared in thin slides for electron microprobe analyzer (EMPA) and optical investigations, using a Babinet compensator and a Rayleigh interferometer. The results show that the quartz samples belonging to the Contu-Negovanu granitic pegmatites are chemically very pure, showing an expected high participation of silica and only some remarkable contents of Fe, derived from iron oxide micro-inclusions finely disseminated in the quartz grains. The minor and trace elements distribution suggests that different crystallization conditions influenced the quartz composition, thus resulting some rather high contents of Ba, Rb, Sr and some REE contents (Ce) in the pegmatite quartz crystallized from alkali- and alkaline-earth-rich fluids, while the metamorphic quartz appears to be highly pure, showing no such presence. The analyzed quartz samples present birefringence parameters within the limits of other quartz samples and a decrease of the linear birefringence of quartz with the light wavelength increase is emphasized by the data obtained using the channeled spectrum.

scholarly journals Vapor Transport and Deposition of Cu-Sn-Co-Ag Alloys in Vesicles in Mafic Volcanic Rocks

2020 ◽  
Vol 115 (2) ◽  
pp. 279-301
Author(s):  
Elizabeth A.O. Hunter ◽  
Jacob R. Hunter ◽  
Zoltan Zajacz ◽  
Jeffrey D. Keith ◽  
Nichelle L. Hann ◽  
...  
Keyword(s):  
Vapor Phase ◽  
Inductively Coupled Plasma ◽  
Melt Inclusions ◽  
Volcanic Rocks ◽  
Alloy Element ◽  
Mass Spectrometry Analysis ◽  
Silicate Melts ◽  
Spectrometry Analysis ◽  
Inductively Coupled ◽  
Metallic Grains

Abstract Metallic sublimates coated by sulfides and chlorides line the vesicle walls of mafic volcanic lava and bombs from Kīlauea, Vesuvius, Etna, and Stromboli. The metallic sublimates were morphologically and compositionally similar among the volcanoes. The highest concentrations of S and Cl occurred on the surface of the sublimates, while internally they had less than 1 wt % S and Cl in most cases, leading us to classify them as alloys. The major components of the alloys were Cu, Sn, Co, and Ag based on electron microprobe analyses and environmental scanning electron microscope element maps. Alloy element maps showed a covariance of Cu-Sn, while Co and Ag concentrations varied independently. Laser ablation-inductively coupled plasma-mass spectrometry analysis of matrix glass and melt inclusions in bombs from Stromboli showed appreciable amounts of Cu, Co, and Sn. We propose a model for the origin of the metallic grains, which involves syneruptive and posteruptive magma degassing and subsequent cooling of the basalt vesicles. During syneruptive vapor phase exsolution, volatile metals (Cu, Co, and Sn) partition into the vapor along with their ligands, S and Cl. The apparent oxygen fugacity (fO2) in these vapor bubbles is low because of the relative enrichment of the exsolved gas phase in H2 relative to H2O in silicate melts, due to the much higher diffusivity of the former in silicate melts. The high fH2 and low fO2 induces the precipitation of metal alloys from the vapor phase. Subsequently, the reducing environment in the vesicle dissipates as the cooling vapor oxidizes and as H2 diffuses away. Then, metal-rich sulfides (and chlorides) condense onto the outer surfaces of the metal alloy grains either due to a decrease in temperature or an increase in fO2. These alloys provide important insights into the partitioning of metals into a magmatic volatile phase at low pressure and high temperature.

scholarly journals Geochemical characterisation of Otumba obsidian sub-sources (Central Mexico) by inductively coupled plasma mass spectrometry and density-based spatial clustering of applications with noise statistical analysis

2013 ◽  
Vol 1 (1) ◽  
pp. 18 ◽  
Author(s):  
Denisse Argote-Espino ◽  
Jesús Solé ◽  
Pedro López-García ◽  
Osvaldo Sterpone
Keyword(s):  
Mass Spectrometry ◽  
Inductively Coupled Plasma ◽  
Spatial Clustering ◽  
Central Mexico ◽  
Inductively Coupled ◽  
Icp Ms ◽  
Lithic Industry ◽  
Plasma Mass Spectrometry ◽  
The One ◽  
The Individual

Several obsidian sources that were significant to the lithic industry all over Mesoamerica are contained in the Central Mexico highlands. Many archaeological investigations have suggested that the economical and political expansion of important Mesoamerican cultures was related to the control of obsidian sources and its commercial routes. One of these sources was Otumba, located west of the Teotihuacan Valley. This region has several sub-sources, some of which have been studied in more detail than others. The most studied subsource is the one located on Soltepec Hill, but other related sub-sources within Otumba region that have not been studied include the Ixtete, Pacheco, Malpais and Tepayo domes. We have analysed samples from these four sub-sources with inductively coupled plasma mass spectrometry (ICP-MS) method to determine their chemical similarities and differences and classify them. The individual correlation of different archaeological artifacts with each sub-source could tell us about exploitation preferences of the diverse cultures controlling the source or even sequence in time of its utilisation.

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