Fig. 5
a Relative contribution of the three major litho-tectonic units (sedimentary, ophiolitic and crystalline nappes) on the composition of the material at the sites Lan-10, Lan-5 and Lan-1. The composition has been determined for the silt fraction, and the relative contribution of these litho-tectonic units on the bulk composition of the material is based on the results of the composition modelling (results of model run 2 of Table 5). b Results of mixing modelling, where the material derived between the sites Lan-10 and Lan-5 has been assigned a composition made up of 100% of sedimentary constituents. The relative contribution of the various segments on the downstream changes of the material composition has been iteratively changed until the calculated compositions correspond to the measured ones. DEM ©swisstopo