**6. Conclusions and future researches**

The outstanding questions on Monte Amiata sheet-like trachydacite that we discuss in this work are mainly related to the interpretation of its eruption mechanisms (effusive vs. explosive volcanism) that we have faced with an unprecedented physical and volcanological characterization of the products and by comparing our results with the updated models of ignimbrite and rheoignimbrite. The identification of several

*Physical Volcanology and Facies Analysis of Silicic Lavas: Monte Amiata Volcano (Italy) DOI: http://dx.doi.org/10.5772/intechopen.108348*

lava flow eruptive units (referring to different eruptive events and vents location) having different stratigraphic position and composed of several flow units separated by scoria or breccia beds is the first argument for this discussion. The second main discussion point is the manner of flowing of single lava flows and the reasons for producing the different volcanic facies and structures we observed and described. Our results point out to a model for the formation of the Monte Amiata SLLFs which could possibly be extended to other silicic composite volcanoes.

In major detail, our field-based study of the trachydacite SLLFs of Monte Amiata supports these conclusions:


Looking to the future, the data still missing on Monte Amiata products are represented by the quantification of the volatile content in magmas, and by the definition of the silicic-magma/mafic-magma ratio characterizing the feeding of the single events. Obtaining these further pieces of information will allow us to further

refine the model presented here for the formation of SLLFs and, in a broader perspective, the model of the other lithofacies (lava domes and coulées) that have been emplaced during the various phases of the life of the completely silicic Monte Amiata volcano.
