Which structure is most similar to an alluvial fan in formation and composition? f watershed g river h lake j delta?

Delta

Delta fan is a low lying plain that is made up stream –borne sediments deposited by the river at its mouth. Delta fans forms where a river enters a body of standing water, however, soil and minerals that was carried along the moving water drops and it spread out by the force of the water in fan shape. 

igneous rocks are formed by solidification of cooled magma (molten rock), with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks.  

the composition depends on the source magma. there are almost a thousand types of composition found till now.  

hope this