Can I read Feldspar Raman shift and application as a magmatic thermobarometer on EtoBox?

Feldspar Raman shift and application as a magmatic thermobarometer by Kenneth S. Befus; Jung-Fu Lin; Miguel Cisneros; Suyu Fu is a Earth and Planetary Sciences article available to read on EtoBox.

What is Feldspar Raman shift and application as a magmatic thermobarometer about?

We calibrate the pressure-dependent Raman shift of feldspars by measuring spectra of 9 compositionally diverse plagioclase and alkali feldspars at pressures ranging between 0.1 MPa and 3.6 GPa using a diamond-anvil cell coupled with Raman spectroscopy. We observe up to 12 vibrational modes that are caused by deformation of Si(Al)O 4 tetrahedral chains. The most intense modes are v 22 , v 24 , and v 25 , which are produced by stretching and bending of four-membered Si(Al)-O-Si(Al) rings. Because modes are a product of lattice environments, feldspar composition may relate to mode frequency. We find that the frequencies of the v 25 mode correlates with composition, whereas the other intense bands do not correlate with composition. All feldspar compositions exhibit modes that shift linearly (r 2 > 0.9) to higher frequencies with increasing pressure. Modes v 22 , v 24 , and v 25 shift to higher frequencies with slopes that range from 1.7 ± 0.5 to 5.5 ± 1.6 cm -1 GPa -1 , and provide the best combination of intensity and pressure-sensitivity. For all compositions the v 22 mode exhibits the most advantageous pressure-dependent (P-T) frequency shift. We use an elastic model, thermodynamic

Who reads Feldspar Raman shift and application as a magmatic thermobarometer?

Author

Kenneth S. Befus; Jung-Fu Lin; Miguel Cisneros; Suyu Fu

Published

2018

Language

EN

Field

Earth and Planetary Sciences (Physical Sciences)