scholarly journals REE Geochemical Characteristic of Apatite: Implications for Ore Genesis of the Zhijin Phosphorite

Minerals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1012
Author(s):  
Liu Xiqiang ◽  
Zhang Hui ◽  
Tang Yong ◽  
Liu Yunlong
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Ore Deposits ◽  
Inductively Coupled ◽  
Ree Distribution ◽  
Phosphorite Deposit ◽  
Heavy Rare Earth Elements ◽  
Plasma Mass Spectrometry ◽  
Geochemical Analyses

Phosphorite-type rare earth deposits, which are one of the important types of rare earth elements (REE) ore deposits, have attracted increasing attention because of the extreme enrichments in heavy rare earth elements (HREE), including Yttrium (Y). In this study, in situ geochemical analyses of apatite grains from Zhijin phosphorites were conducted using electron probe microanalysis (EMPA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Based on EPMA mapping analysis, we show that rare earth elements and Yttrium (REY) entering into the crystal lattice by isomorphism rather than by inclusions of REY-bearing accessory minerals. The post-Archean Australian Shales (PAAS)-normalized REY patterns of the apatite grains are characterized by hat-shaped MREE-enriched patterns. We interpret that this pattern may reflect the REE distribution of seawater at that time. We propose that in a local, reducing environment, dramatically increased the concentration of REY in seawater, and resulted in the MREE-enriched patterns in the ancient ocean. The main mechanism for the genesis of the Zhijin phosphorite deposit is the apatite crystallizes during the mixing process of REY- and P-rich fluid and oxidizing seawater.

scholarly journals Composition of Garnet from the Xianghualing Skarn Sn Deposit, South China: Its Petrogenetic Significance and Exploration Potential

Minerals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 456 ◽  
Author(s):  
Fan Yu ◽  
Qihai Shu ◽  
Xudong Niu ◽  
Kai Xing ◽  
Linlong Li ◽  
...  
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Major And Trace Elements ◽  
Inductively Coupled ◽  
Metallogenic Belt ◽  
Icp Ms ◽  
Heavy Rare Earth Elements ◽  
Plasma Mass Spectrometry ◽  
Southern Hunan

The Xianghualing skarn Sn deposit in the southwestern part of the southern Hunan Metallogenic Belt is a large Sn deposit in the Nanling area. In this paper, the garnet has been analyzed by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to obtain the concentrations of the major and trace elements. The results reveal that the garnets from the Xianghualing deposit mainly belong to andradite-grossular (grandite) solid solution and are typically richer in Al than in Fe. They show enrichment in heavy rare earth elements (HREEs) and notably lower light rare earth elements (LREEs), and commonly negative Eu anomalies, indicative of a relatively reduced formation environment. The garnets have high Sn concentrations between 2313 ppm and 5766 ppm. It is also evident that there is a positive correlation between Sn and Fe, suggesting that Sn4+ substitutes into the garnets through substituting for Fe3+ in the octahedral position. Combined with previous studies, it can be recognized that the Sn concentrations of garnet in skarn Sn deposits are generally high, whereas the W concentrations are relatively low. This is just the opposite in garnets from skarn W deposits that typically have high W, but low Sn concentrations. In polymetallic skarn deposits with both economic Sn and W, the concentrations of both metals in garnets are relatively high, although varying greatly. Therefore, the Sn and W concentrations in garnets can be used to evaluate a skarn deposit’s potential to produce Sn and (or) W mineralization, which is helpful in exploration.

Geochemistry of major, trace and rare earth elements in coals from the Tazareh mine, eastern Alborz coalfield, NE Iran

2020 ◽  
Vol 20 (3) ◽  
pp. 381-398
Author(s):  
Afieh Tatar ◽  
Masood Alipour-Asll
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Inductively Coupled Plasma ◽  
Hanging Wall ◽  
Optical Emission ◽  
Emission Spectrometry ◽  
Humid Climate ◽  
Inductively Coupled ◽  
Plasma Mass Spectrometry ◽  
Host Rocks

The Tazareh mine in the eastern Alborz coalfield is one of the most important coal-producing areas in Iran and contains medium volatile (19.1–31.5%), low sulfur (0.015–0.491%) and variable ash yield (3–31.5%) bituminous coal. In this research, a total of 21 samples were collected from the Tazareh coal layers, footwall and hanging wall. The concentrations of rare earth elements (REEs) and other elements were determined by inductively coupled-plasma mass spectrometry (ICP-MS) and inductively coupled plasma-optical emission spectrometry (ICP-OES). Additionally, traditional features of coal and host rocks were studied by X-ray diffraction (XRD) and petrographic methods. The concentration coefficient (CC) of Tazareh coal samples show that Sc (CC = 2.71), Be (CC = 2.68) and Ni (CC = 2.30) are slightly enriched, Li, Cr, Pb, Sb, V, Cs, As, Co, Cu, Nb, Y, Rb, Tl, REE, Zr, Zn, Ta and Th (0.5 < CC < 2) are normal, and concentrations of remaining trace elements are lower than the average world hard coals. The NASC-normalized REEs pattern and (La/Yb)n, (La/Sm)n, (Gd/Yb)n, and (La/Lu)n ratios in the Tazareh coal confirm that the LREEs are enriched relative to HREEs, and comparatively, the degree of LREE enrichment of coal is lower than that of coal-bearing shale and argillaceous shale. Coal-bearing strata were deposited under oxic conditions in a warm-humid climate. The average content of REE + Y in Tazareh coal (58 ppm) is lower than world coals (83 ppm), while Sc is enriched.

Sign in / Sign up

Export Citation Format

Share Document