Glasses Tech

March 8, 2010

Analytical techniques for volatiles: A case study using intermediate (andesitic) glasses

Filed under: Glasses 2002 — admin @ 4:28 am

Eyeglasses

Small-scale analyses of volatiles in minerals and glasses provide information on how volatiles influence high-temperature geologic processes and low-temperature alteration processes. Four techniques for determining the C-O-H volatile contents of andesitic glasses are compared: manometry, secondary ion mass spectrometry, micro-Fourier transform infrared spectroscopy, and a technique where the H2O content is calculated using the difference between electron microprobe analysis totals and 100% sum. We present a method to determine the H content of a wide range of glass and mineral compositions using secondary ion mass spectrometry and a model for calibration factors. (more…)

Volatiles in Submarine Basaltic Glasses from the Northern Kerguelen Plateau (ODP Site 1140): Implications for Source Region Compositions, Magmatic Processes, and Plateau Subsidence

Filed under: Glasses 2002 — admin @ 4:21 am

Submarine pillow basalts (34 Ma) recovered from the Northern Kerguelen Plateau at ODP Site 1140 contain abundant unaltered glass, providing the first opportunity to measure the volatile contents of tholeiitic basaltic magmas related to the Kerguelen mantle plume. The glasses have La/Sm and Nb/Zr ratios that vary from values similar to Southeast Indian Ridge (SEIR) MORB (Unit 1), to slightly more enriched (Unit 6), to values transitional between SEIR MORB and basaltic magmas formed by melting of the Kerguelen plume (Units 2 and 3). Volatile contents for glasses in Units 1 and 6 are similar to depleted mid-ocean ridge basalt (MORB) values (0·25–0·27 wt % H2O, 1240–1450 ppm S, 42–54 ppm Cl). (more…)

Fe and Mn K-edge XANES study of ancient Roman glasses

Filed under: Glasses 2002 — admin @ 4:20 am

1 Dipartimento di Scienze della Terra, Università di Messina, Salita Sperone 31, I–98166 S. Agata di Messina, Italy
2 Istituto Nazionale per la Fisica della Materia and Dipartimento di Fisica, Università di Bologna, viale Berti Pichat 6/2, I–40127 Bologna, Italy
3 European Synchrotron Radiation Facility, BP 220, F-38043 Grenoble, France

* Corresponding author, e-mail: simonaq@unimo.it

The X-ray Absorption Near Edge Structure technique has been successfully applied to the study of ancient glasses from Patti Roman Villa (Messina, Sicily). (more…)

Infrared Spectrometric Study of Acid-degradable Glasses

Filed under: Glasses 2002 — admin @ 4:19 am

The composition of glasses used in glass-ionomer cements affects their leaching behavior and hence the properties of the cement. The aim of this study was to correlate the composition and leaching behavior of these glasses with their infrared absorption characteristics. The wavenumber of the absorption band of the Si-O asymmetric stretching vibration AS shifts to a higher value with decreasing content of mono- and bivalent cations in the glass. (more…)

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