NMR Relaxation Behavior of Moderately Shocked Sandstone from Meteor Crater, Arizona
Abstract
Nuclear magnetic resonance (NMR) spectroscopy provides a sensitive and reliable tool for the identification and characterization of shocked minerals resulting from natural impact as well as from shock experiments. We previously characterized the relaxation behavior of experimentally-shocked quartz by determining the T1 relaxation times of crystalline and amorphous phases, showing that time dependence of the magnetization for each phase follows a power-law function before reaching a saturation plateau. We have now applied this method to characterize the complex mixture of silica phases and composition of moderately shocked Coconino Sandstone from Meteor Crater, Arizona. Our new results indicate that, as for the previous work, each phase exhibits power-law behavior followed by saturation. Moreover, the natural samples contain three additional phases, and relaxation analysis can be used to determine the relative abundances of quartz, coesite, stishovite, and a dense hydrated amorphous silica.
- Publication:
-
Lunar and Planetary Science Conference
- Pub Date:
- March 1996
- Bibcode:
- 1996LPI....27..283C
- Keywords:
-
- IMPACTS;
- METAMORPHISM: SHOCK;
- METEOR CRATER: ARIZONA;
- MINERALS: SHOCKED;
- SPECTROSCOPY: NUCLEAR MAGNETIC RESONANCE