Rock-on-rocks and sites within water break-out zones - Harvard, Bolton

I was going south, traversing a slight slope with lower wetland to my right (to the west) and higher, drier, pine sapling woods to my left. Came across a pair of rock-on-rocks and then found a little cluster of piles, each with no more than a handful of rocks. Most of the slope had been eroded and had little topsoil - so it was hay-scented ferns except where the saplings got too dense. Here are a couple of the rock-on-rocks with similar structure: One comment is that these are big rocks, too big for me to lift. I noticed a couple of rock-on-rocks where the upper rock has a shape that I think is significant. Both rocks have an extended "neck". I used to believe this was a "heart" shape. But I don't know what it is. I just believe there is a deliberate shape similarity here and it is not a coincidence. Here are some of the more complex piles. I think these have all been pretty bashed around. This kind of site, with numerous rock-on-rocks in a wet place is yet another kind of rock pile site. I do not know anything much about its function but it appears different from the previous site I reported.