I look at it this way:
We have a “wet area.” An upper strata of that wet area had organics to the extent that grass grew. A lower strata did not. The lower strata, like the upper strata was still within a zone we are calling a wet area.
The lower strata, when saturated, would sometimes be also exposed to rain. The rain would repeatedly carry off the “fines”, such a fine sands and smaller grained non-organics. As it did so, the larger gravels were striated into rivulets due to the action of the small grains being carried by water pushing the larger cobbles into stripes.
We have a wet area, [the Christy Jones Memorial Lawn and Undermined Area] An upper strata of that wet area had organics to the extent that grass grew. A lower strata did not. The lower strata, like the upper strata was still within a zone we are calling a wet area.
There...fixed it.