Decay of trachyte used as building stone in urban environment was investigated through the analysis of crusts and patinas found on trachyte of the Euganean Hills in the Renaissance city walls of Padua, northeastern Italy. Mineralogical and microstructural characteristics of the alteration products, as well as majorand trace-element chemical composition, were determined by optical microscopy, SE...

Abstract Inexpensive sintered glass-ceramic glaze was prepared from a mixture of Egyptian trachyte with either limestone or magnesite. A represented rock pulverized to powder (<0.083 mm) and also both The well mixed batches were melted near 1450 °C/3 h temperature then the glass melt quenched in water, dried, finally shaped moulds. sintering process pre-shaped glasses, within 1000-1100 °C ra...

A flinty, spherulitic dyke of peralkaiine trachyte in a Precambrian dyke-swarm consists mainly of albite and aegirine. Within this, euhedral crystals of narsarsukite, NadTi,Fe)Si401o(F), occur as short prisms elongate parallel to c. This distinguishes them from all previously described narsarsukites, which have tabular habits. Minor phases present include micas, apatite, quartz, pectolite, nord...

Centimeter-scale magmatic enclaves are abundant in peralkaline felsic volcanic rocks the Sanshui Basin. Their lithology is mainly syenite and syenitic porphyry, they comprise alkali feldspar amphibole, which similar to mineral assemblage of host trachyte comendite. The SiO2 content ~63 wt%, that but lower than Thermobarometric calculations showed crystallized at temperature pressure conditions ...

A tephrostratigraphy of the active Antarctic volcano, Mt. Erebus, was determined from englacial tephra on the ice-covered flanks of Erebus and an adjacent volcano. The tephra are, used to reconstruct the eruptive history and magmatic evolution of Erebus. Scanning electron microscope images and Image Particle Analysis suggest the tephra formed in phreatomagmatic and magmatic eruptions and in som...

Tracks of mass unsted houtders are examined on the slope of a steep hill 3 km east of Peter and Paul in the southwestern desert of Egypt. The hill is what remains of a vol cania neck of trachytes and basal aonglomerates, The hill is surrounded by an apron of debris in which the tracks are grooved. One 2 m boulder left a straight trail and its motion appears to have been smooth. It continued to ...

Abstract Apatite can incorporate significant amounts of H2O and CO2, potentially recording volatile abundance behavior during magma evolution. Here we conducted in situ measurements CO2 concentrations apatite, along with elemental compositions, from two contemporaneous alkaline volcanic suites (Tianbao Tudiling) the South Qinling belt central China to better understand contents evolving melts. ...