TitaniQ under pressure: the effect of pressure and temperature on the solubility of Ti in quartz期刊界 All Journals 搜尽天下杂志传播学术成果专业期刊搜索期刊信息化学术搜索

TitaniQ under pressure: the effect of pressure and temperature on the solubility of Ti in quartz

Authors:

Jay B. Thomas E. Bruce Watson Frank S. Spear Philip T. Shemella Saroj K. Nayak Antonio Lanzirotti

Affiliation:

(1) Department of Earth and Environmental Sciences, Rensselaer Polytechnic Institute, 110 8th St., Troy, NY 12180, USA;(2) Department of Physics, Applied Physics, and Astronomy, Rensselaer Polytechnic Institute, Troy, NY 12180, USA;(3) National Synchrotron Light Source, Brookhaven National Laboratory, The University of Chicago—CARS, Upton, NY 11973, USA

Abstract:

Quartz and rutile were synthesized from silica-saturated aqueous fluids between 5 and 20 kbar and from 700 to 940°C in a piston-cylinder apparatus to explore the potential pressure effect on Ti solubility in quartz. A systematic decrease in Ti-in-quartz solubility occurs between 5 and 20 kbar. Titanium K-edge X-ray absorption near-edge structure (XANES) measurements demonstrate that Ti⁴⁺ substitutes for Si⁴⁺ on fourfold tetrahedral sites in quartz at all conditions studied. Molecular dynamic simulations support XANES measurements and demonstrate that Ti incorporation onto fourfold sites is favored over interstitial solubility mechanisms. To account for the P–T dependence of Ti-in-quartz solubility, a least-squares method was used to fit Ti concentrations in quartz from all experiments to the simple expression

RTlnX_textTiO₂^textquartz = - 60952 + 1.520 ·T(K) - 1741 ·P(kbar) + RTlna_textTiO₂ RTln X_{{{text{TiO}}_{ 2} }}^{text{quartz}} = - 60952 + 1.520 cdot T(K) - 1741 cdot P(kbar) + RTln a_{{{text{TiO}}_{ 2} }}

Keywords:
本文献已被 SpringerLink 等数据库收录！

设为首页 | 免责声明 | 关于勤云 | 加入收藏