Figure 1.

The right map shows the Amarillo River and the sampling point locations in La Rioja, Argentina. (a,c,f) Satellite images of the sampling sites RA8, RA5 and RA2 (including the sampling point of the Cueva de Perez formation), respectively. (b,e) Images of the Amarillo River yellow waters in sampling points RA8 and RA5, respectively. (d) Image of the ochreous-yellowish sediments present in the river basin at sampling point RA5. (g,j) Images of the Amarillo River and the terraces from the Cueva de Perez formation in the RA2 area. (h,i) Image of a green streamer and a red pool found in the RA2 area, respectively.