I read the paper, I think that this is pseudoscience garbage, in my non-expert opinion. I think the sphericles can be explained geologically, the "growth" of the pebbles is explained, as others have pointed out, by the sand around them being removed and being exposed more.
I don't like to do this because I would rather attack the evidence but for context, look at the author's history and other publications on researchgate as /bluenose69 pointed out. Read the wikipedia article on the "Journal of Cosmology". This author has a belief that there is life on Mars, and if it isn't puffballs like this paper, it is lichens, or stomatotites. Or suing NASA to examine a rock that was flipped by the wheel of Opportunity that the rock was alive and moved around.