In:
Revista Mexicana de Ciencias Geológicas, Universidad Nacional Autonoma de Mexico, Vol. 34, No. 3 ( 2017-11-29), p. 170-
Abstract:
Petrographic, chemical and mineralogical studies were performed on a fulgurite formed by melting of soil by lightning strike located at San José de Lourdes, northeast of Fresnillo, State of Zacatecas, Mexico. Polarizing microscopy, scanning electron microscopy with EDS, micro- probe WDS analyses, micro-Raman spectroscopy, X-ray diffraction and X-ray fluorescence were used as analytical methods. Most of the specimens are tubular and have a smooth, lustrous, black, glassy texture while the exterior is encrusted with soil grains. Internally, this fulgurite is partly composed of heterogeneous vesicular glass mostly of andesitic composi- tion containing fragments of skeletal crystals of wollastonite and unde- termined Fe- silicate, spheroids of SiO2 similar to ballen quartz within the glass. The presence of very fine and scarce grains of ilmenite, zircon, apatite, silver and gold besides some Si-Fe alloys (silicides) of variable composition and arsenic-calcium compounds (which is found for the first time in fulgurites) is also reported. We estimate that the temperatures of crystallization were above 1,700 °C considering into account the melting of quartz and presence of reduced phases.
Type of Medium:
Online Resource
ISSN:
2007-2902
,
1026-8774
DOI:
10.22201/cgeo.20072902e.2017.3
DOI:
10.22201/cgeo.20072902e.2017.3.477
Language:
Unknown
Publisher:
Universidad Nacional Autonoma de Mexico
Publication Date:
2017
detail.hit.zdb_id:
2194771-5
SSG:
7,36
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