Routine characterization and interpretation of complex alkali feldspar intergrowths

摘要: Almost all alkali feldspar crystals contain a rich inventory of exsolution, twin, and domain microtextures that form subsequent to crystal growth provide record the thermal history often its involvement in replacement reactions, sometimes multiple. Microtextures strongly influence behavior feldspars at low temperatures during diagenesis weathering. They are central retention or exchange trace elements radiogenic stable isotopes. This review is aimed petrologists geochemists who wish use solve geological problems need understand how particular process. We suggest systematic approach employs methods available most well founded laboratories. The crystallographic relationships complex intergrowths were established by 1970s, mainly using single-crystal X-ray diffraction, but such give limited information on spatial different microtexture, mode chronology their formation, which require microscopy. combination techniques with range resolution recommend orientated sections. Sections cut parallel perfect (001) (010) cleavages easiest locate informative. Techniques described light microscopy; scanning electron microscopy both backscattered secondary electrons, including surfaces etched laboratory; electron-probe microanalysis analysis energy-dispersive spectrometry microscope; transmission discuss cathodoluminescence as an auxiliary technique, do not electron-backscattered diffraction for work. recent publications examples great care attention pre-existing work microtextural studies, several topics future