Gateways, Doorways, Windows - interpreting gaps, cracks, and veins in rocks

I increasingly believe that Native American ceremonialism included an understanding of spaces between rocks ("gaps"), cracks in rocks, and veins of other material within a rock. What this understanding was I don't know. One can only look at how things are being used and where they occur and what they occur in conjunction with, to try to make reasonable guesses. So here is a site at the Sargent Farm Conservation Land in Stow that occurs on a westward facing slope, at a spring - a place where water comes out of the ground with a few simple rock pile constructions all around. Here we see patterns that occur over and over at springs or at places along a brook - often where there are waterfalls or cataracts or, at least, the sound of water gurgling. Here is a first such pattern - a gap between two rocks, enhanced with some simple rock piling:Notice how the gap opens up towards a puddle of water in the background; also notice there is a smaller, subtler gap along that same line but a few feet beyond the first one. Here is a gap or a crack (narrower than a gap, not large enough for a person to walk through) that is filled with smaller rocks. I suspect this means something different than a gap. And here is another a few feet away:I could not see that these were pointed towards the water, like the gap, but I failed to observe carefully. Another very common pattern is a crack that is roofed over with a few smaller rocks. Maybe this is like the last two examples, maybe it is something different. In my little "cosmology" I imagine cracks that open downward had a particular significance - perhaps as doorways to an unpleasant spirit world, needing to be blocked. I was walking around looking at these and spotted a very noticeable black rock-on-rock: (closer)(another view)I was not until I got home and looked at the pictures that I noticed the black rock is sitting over a vein of quartz. There is some similarity to the covered crack of the previous pictures and I have very little doubt that this black rock was selected because of its deep color and iron rich composition. Did we think of quartz veins as having so much power that this was required? It is a new pattern for me and a pretty dramatic example.

I believe these gaps, cracks, and veins are a major part of what was going on at this site and my guess is that it has to do with channeling of "energy" both positive and negative, creating an interplay and perhaps balancing of forces. Some explanation is needed for why all these similar patterns occur in one place.

Finally let's take a closeup of some of the little rock piles:The neargound pile might actually be part of a small "gap", because of the second rock next to it. A closeup of the far pile, suggests its components are not random rocks:
I wonder about the shape of the lower rock, and about its composition:But that is another story.