Quantitative studies on the volcanic rocks texture; shape, crystal size distribution(CSD), and spatial distribution pattern (SDP)

In this research, our focus has been on the quantitative calculations of the texture of volcanic rocks. For this purpose, the rocks with acidic tobasic and ultra-basic combinations were selected, and the shape, size, and spatial distribution (CSD and SDP) of their phenocrysts wereinvestigated. The results showed that in volcanic rocks, the ratio of nucleation to crystal growth (J/G) was several times higher and crystalgrowth per time unit (Gt) was higher in rocks with fewer nuclei. It also turns out that to evaluate the magma mixing, CSD pattern analysis canbe instrumental. The spatial distribution of grains in the extrusive rocks is clustered to random, probably due to the high degree ofoverstepping and under-cooling conditions. The mineral clusters may form before emplacement of the flow, at depth during the residencetime before the eruption flow, or throughout the rise and flow. The importance of these results displays that due to the progress of imagingmethods and statistical-numerical work on crystals and textures; it is time that all petrologists from all over the world, along with geochemicalwork, pay attention to these types of studies to provide a complete petrological work.

کلیدواژه ها:

CSD ، SDP ، Shape ، textural measurements