SiO2 Solubility in Rutile at High Temperature and High Pressure

CORC > 中国地质调查局 > 中国地质调查局

	SiO2 Solubility in Rutile at High Temperature and High Pressure
	Ren, YF (Ren Yufeng); Fei, YW (Fei Yingwei); Yang, JS (Yang Jingsui); Bai, WJ (Bai Wenji)
刊名	JOURNAL OF EARTH SCIENCE
	2009
卷号	20 期号:2 页码:274-283
关键词	rutile stishovite coesite polymorph high temperature and high pressure experiment
ISSN号	1674-487X
英文摘要	Silicon-bearing rutile has been found in chromitite from the Luobusa ((sic)) ophiolite, Tibet. However, the extent Of SiO2 solubility in rutile and the nature of its origin are still unclear. At high pressure, SiO2 takes a rutile structure with Si in 6-fold coordination. Thus, high pressures may enhance its solubility in rutile because of possible isovalent exchange in the octahedral site. In this study, we report new experimental results on SiO2 Solubility in rutile up to 23 GPa and 2 000 degrees C. Starting materials were mixtures of powdered pure rutile and pure quartz, with compositions of (Ti0.5Si0.5)O-2, (Ti0.93Si0.07)O-2, and (Ti0.75Si0.25)O-2. The mixtures were loaded into either platinum capsules (for a 10/5 assembly) or rhenium capsules (for an 8/3 assembly). The experiments were carried out using multi-anvil high-pressure apparatus with a rhenium resistance heater. Sample temperatures were measured with a W5%Re-W26%Re thermocouple and were controlled within +/- 1 degrees C of the set temperature. TiO2-rich and SiO2-rich phases were produced in all the quenched samples. Microprobe analyses of the phases show that the solubility of SiO2 in rutile increases with increasing pressure, from 1.5 wt.% SiO2 at 10 GPa to 3.8 wt.% SiO2 at 23 GPa at a temperature of 1 800 degrees C. The solubility also increases with increasing temperature from 0.5 wt.% SiO2 at 1 500 degrees C to 4.5 wt.% SiO2 at 2 000 degrees C at a pressure of 18 GPa. On the other hand, the solubility of TiO2 in coesite or stishovite is very limited, with an average of 0.6 wt.% TO2 over the experimental P-T ranges. Temperature has a much larger effect on the solubility of SiO2 in rutile than pressure. At high pressure, the melting point of SiO2 is definitely higher than that of TiO2 and the eutectic point moves towards SiO2 in the TiO2-SiO2 system. Lower oxygen fugacity decreases the solubility Of SiO2 in rutile, whereas water has little effect on the solubility. Our experimental data are extremely useful for determining the depth of origin of the SiO2-bearing rutile found in nature.
学科主题	岩矿鉴定与测试
WOS关键词	SYSTEM MG2SIO4-FE2SIO4 ; LUOBUSA OPHIOLITE ; OLIVINE ; CHROMITITES ; TITANITE ; BEARING ; TIBET ; TIO2
WOS研究方向	Geology
语种	英语
出版者	CHINA UNIV GEOSCIENCES
WOS记录号	WOS:000265653900006
内容类型	期刊论文
源URL	[http://119.78.100.197/handle/2HKVOGP0/39054]
专题	中国地质调查局
作者单位	Carnegie Inst Washington, Geophys Lab, Washington, DC 20015 USA
推荐引用方式 GB/T 7714	Ren, YF ,Fei, YW ,Yang, JS ,et al. SiO2 Solubility in Rutile at High Temperature and High Pressure[J]. JOURNAL OF EARTH SCIENCE,2009,20(2):274-283.
APA	Ren, YF ,Fei, YW ,Yang, JS ,&Bai, WJ .(2009).SiO2 Solubility in Rutile at High Temperature and High Pressure.JOURNAL OF EARTH SCIENCE,20(2),274-283.
MLA	Ren, YF ,et al."SiO2 Solubility in Rutile at High Temperature and High Pressure".JOURNAL OF EARTH SCIENCE 20.2(2009):274-283.