RT info:eu-repo/semantics/article
T1 Multispectroscopic methodology to study Libyan desert glass and its formation conditions
A1 Gómez Nubla, Leticia
A1 Aramendia, Julene
A1 Fernández Ortiz de Vallejuelo, Silvia
A1 Alonso Olazabal, Ainhoa
A1 Castro, Kepa
A1 Zuluaga, María Cruz
A1 Ortega, Luis Ángel
A1 Murelaga, Xabier
A1 Madariaga Mota, Juan Manuel
AB Libyan desert glass (LDG) is a melt product whoseorigin is still a matter of controversy. With the purpose ofadding new information about this enigma, the present paperanalyzes the inner part of LDG specimens and compares themwith the results of LDG surfaces. An integrated analyticalmethodology was used combining different techniques suchas Raman spectroscopy, in point-by-point and imaging modes,scanning electron microscopy with X-ray microanalysis(SEM-EDS), energy-dispersive micro X-ray fluorescencespectrometry (μ-EDXRF), electron probe micro analyzer(EPMA), and optical cathodoluminescence (Optical-CL).According to our results, flow structures of the melt and theamorphous nature of the matrix could be discerned. Moreover,the observed displacement of Raman bands, such as in thecases of quartz and zircon, and the identification of certaincompounds such as coesite (the most clarifying phase of highpressures), α-cristobalite, gypsum, anhydrite, corundum, rutile,amorphous calcite, aragonite, and calcite allowed us toknow that LDGs could be subjected to shock pressures between6 and more than 30 GPa, and temperatures between 300and 1470 °C. The differences of temperature and pressurewould be provoked by different cooling processes during theimpact. Besides, in most cases the minerals corresponding tohigh pressure and temperatures were located in the inner partof the LDGs, with some exceptions that could be explainedbecause they were trapped subsequently to the impact; therewas more than one impact or heterogeneous cooling.Furthermore, nitrogen and oxygen gases were identifiedinside bubbles, which could have been introduced from theterrestrial atmosphere during the meteorite impact.These data helped us to clarify some clues about the originof these enigmatic samples.
YR 2017
FD 2017
LK http://uvadoc.uva.es/handle/10324/35254
UL http://uvadoc.uva.es/handle/10324/35254
LA eng
NO Analytical and Bioanalytical Chemistry 2017, vol. 409, n. 14. p.3597-3610.
DS UVaDOC
RD 30-abr-2024