Hello Dear professors and colleagues
I have a felsic volcanic rock rich in mafic xenoliths and now thinking of the best way from sample preparation to yield best results ...any suggestion?
2- I want to prepare XRF fused beads for the felsic rock .. Should i care for removing the xenolith away before the grinding ?
3- Could i study the xenolith itself as if it was a free geological unit ?
I would go a double-blow strategy
1. Isolate the xenoliths, take a picture and carry out a classification with the unarmed eye or hand lens for chemical analyses which you have already been pondering over. This chemical analyses can start with the common major and minor element XRF analysis and be extended to an advanced level studies including stable and instable isotope (radiometric dating). The non-destructive XRD (also quantitative) can be performed prior to that using the powdered samples to be planed for XRD. Thereby, you get a small-scale overview of the bulk mineral and chemical composition.
2. The second part should capitalize on the first step when it comes to a mineralogical and chemical investigation along transects across the boundary between the xenoliths and the host rock. Thin- and polished section can be used for the various xenolith types 1, 2, 3,…..etc. established under No. 1 step. In the course a that a fine-tuning of No 1 may be achieved and by means of , e.g., EMPA and/or ICPMS the chemical reactions between host and inclusion can be investigated.
It is a rather general approach which can be lifted to a more advanced level. It is only very important to provide a dual – use platform which you can work on, open to various directions and avoiding to block any sort of analysis. A self-designed flow chart , e.g., on PowerPoint can be of assistance because such diagram is always open for amendments.
I wish you much success
HGD
Normally, no xenolith in extrusive volcanic rocks, but we can usually find the mafic segregation. Especially xenoliths are common in the volcanic composition dyke or sill.
In your case, microscopic and petrochemistry (XRF) studies are done simultaneously in both rock types separately. Most of the Xenoliths are earlier than the host rock. You can find these rock types around the area.