The present study provides an overview of the ice nucleation activity of different feldspars varying in their chemical composition and crystal structure. In total 15 different feldspars including plagioclase and alkali feldspars were analyzed for one weight percentage using a special freezing array method called μl-NIPI (microliter Nucleation by Immersed Particle Instrument). Additionally, the ...

Synneusis, the drifting together and systematic attachment of crystals in a melt, is involved in three of the known origins for mantled feldspars: (1) overgrowth, (2) exsolution, and (3) filling of skeletal plagioclase. Quartz latite dikes of the Chocolate Mountains, California, contain plagioclase crystals in parallel and twinned synneusis. Sanidine mantles consisting of segments, each crystal...

Phosphorus and nitrogen are essential macronutrients necessary for the survival of virtually all living organisms. In groundwater systems, these nutrients can be quite scarce and can represent limiting elements for growth of subsurface microorganisms. In this study we examined silicate sources of these elements by characterizing the colonization and weathering of feldspars in situ using field m...

New relationships among the low-temperature alkali feldspars were deduced in part and implied in whole by recent crystal structure analyses of low and high albite and consideration of the electrostatic charge distributions in all the known alkali feldspar structures by Ferguson, Traill & Taylor. In general the most stable low-temperature forms are not those most highly ordered with respect to A...

Hugoniot data for oligoclase and microcline to 670 and 580 kb and release adiabat data for oligoclase were obtained by means of the inclined mirror and immersed-foil-reflected-light techniques, respectively. Oligoclase and microcline have Hugoniot elastic limits in the range of 40-55 and 80-85 kb. These limits increase slightly with increasing driving shock pressure. Above the elastic limit, ex...

Introduction: Minerals subjected to high shock pressures exhibit structural changes with increasing pressure (e.g., fractures, deformations, formation of diaplectic glass, and complete melting [1-6]). Petrologic and thermal infrared spectroscopic studies have shown that diaplectic glass (maskelynite) formation in feldspars occurs between ~25-45 GPa, while significant melting occurs above ~45 GP...

thermal behavior of various solid feldspars are different, namely those of bivalent cations show no change in the distribution of al and si atoms, whereas feldspars of univalent cations become more disordered with raising temperature. in the latter case al atoms migrate from the sites they occupe at low temperatures and interchange positions with the si atoms. at high temperatures (but still be...

The 18-km-diameter El’gygytgyn crater is located on the Chukotka peninsula, northeastern Russia. It represents the only currently known impact structure formed in siliceous volcanics, including tuffs. The impact melt rocks and target rocks provide an excellent opportunity to study shock metamorphism of volcanic rocks. The shockinduced changes observed in porphyritic volcanic rocks from El’gygyt...