re: Spherules are not concretions, as previously hypothesized
Similar to my conclusions. The spheres are all around the same size and they are evenly distributed throughout the parent rock and not confined to one or more layers.
The most logical conclusion I can come up with is that they are biological in origin. But the skeptic in me keeps saying there must be a non-biological explanation.
Tektites would vary in size much more than we see, and they would be confined to layers.
