Other
Scientific paper
Dec 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agufm.p72a0484e&link_type=abstract
American Geophysical Union, Fall Meeting 2002, abstract #P72A-0484
Other
3934 Optical, Infrared, And Raman Spectroscopy, 5464 Remote Sensing, 8494 Instruments And Techniques
Scientific paper
Variations in the surface composition of high silica glassy lavas can provide information about the emplacement history, eruptive style, and structure of flows and domes. However, traditional field mapping of these variations is commonly time consuming, incomplete and impossible for planetary and remote terrestrial environments. Thermal infrared (TIR) remote sensing can provide a more efficient and effective method for mapping this chemical variability. Both high spectral resolution laboratory data and high spatial resolution airborne thermal images were used to evaluate the abundance and composition of crystals in silicic glasses. Image and laboratory thermal emission spectra were collected from the compositionally mixed Glass Mountain flow in northern California, which has a bulk silica content from 57% to 75%. The multispectral image data, acquired using the MODIS/ASTER (MASTER) airborne simulator, were reduced to emissivity and compared to laboratory emission spectra of 40 samples. Data were modeled using a linear deconvolution algorithm to calculate compositional abundances for two end-member suites - one containing rhyolite and dacite bulk rocks and the other containing common phenocryst minerals. Crystal contents derived from the deconvolution approach of the laboratory spectra ranged from 0% in glassy obsidians to more than 48% in the most mafic samples. These modeled abundances generally agreed with values derived from a petrographic analysis, but were higher on average. One possible explanation for this bias is an increased emitted infrared signal due to the presence of microlites and nanolites. Application of the deconvolution-model to the MASTER remote sensing data produced crystal abundance maps that highlight zones of heterogeneity. However, complications due to instrument calibration, the effects of vesicularity, and the moderate spectral resolution limit the accuracy of this approach. As techniques are improved, spectral data from spaceborne instruments, such as ASTER and THEMIS, can be used to characterize glassy lavas on Earth and other planets. Laboratory spectroscopy provides a baseline for this work.
Eisinger C.
Fink Joerg
Ramsey M.
No associations
LandOfFree
Determining Crystal Abundance in Glassy Lavas: Combining Laboratory Infrared Spectroscopy With Remote Sensing does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Determining Crystal Abundance in Glassy Lavas: Combining Laboratory Infrared Spectroscopy With Remote Sensing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Determining Crystal Abundance in Glassy Lavas: Combining Laboratory Infrared Spectroscopy With Remote Sensing will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1892371