Major and trace element of rutile in Xiaohongshan barite quartz veins in Bengbu-Wuhe, eastern Anhui province

Rutile samples were collected from the quartz veins of Xiaohongshan barite in Wuhe area, Bengbu, Eastern Anhui Province, North China, with coordinates N30°56 '16 ", E117°44' 50 ". The quartz veins of Xiaohongshan barite are produced in the Wuhe complex in the form of near bedding. The main minerals in the veins are quartz and barite, and there are centimeter-long columnar rutile, a small amount of metal sulfide and biotite. Among them, rutile has a higher eukaryotic degree, showing reddish brown or black.

It develops from granular crystals with a particle size of about 1 mm to columnar single crystals with a few centimeters in length, with common nuclear edge structure and ring structure, showing a multi-stage growth history.The analysis of mineral major elements was performed by the Electron Probe Laboratory, School of Resources and Environmental Engineering, Hefei University of Technology. The instrument model is JEOL JXA-8230. Experimental conditions: The current is 20 nA, the acceleration voltage is 15 kV, and the beam spot size is 3 ~ 5 μm. For rare earth elements with atomic number < 30, Kα line system is used, while for rare earth elements with atomic number greater than 30, such as Y, Lα line system is used. The peak test duration of Y+REEs is 30 s, the background test duration is 15 s, and the other elements are 10 s and 5 s. Standard sample: Zhou Jianxiong Standard sample group GB/T 17359-1998; And SPI International standard Group (02753-AB53 Minerals standard). Experimental error: ① the relative error of main element (w > 20%) is less than 5% or 3%; ② The element mass fraction is 3% ~ 20%, and the relative error is less than 8%; ③ When the element mass fraction is 1%-3%, the relative error δ is 15%-20%. ④ When the element content is 0.5 ~ 1 wt%, the relative error is controlled between 20%≤δ≤30%.In situ analysis of trace elements in minerals was performed by LA-ICP-MS in the Laboratory of Mineral Microzone Analysis, School of Resources and Environmental Engineering, Hefei University of Technology. The laser denudation system is CetacAnalyte HE and the ICP-MS is Agilent 7900. The error of major and trace elements is 5% and 10% respectively.The results showed that the chemical composition of black rutile and reddish-brown rutile showed obvious difference.