A valid interpretation is that all of these striations are due to glacial action. Calumet Minn. The protolith of this cobble is a conglomerate. Note how the differences in the weathering resistance of each of the grains of this cobble have resulted in a very ruff surface that illustrates quite well differential weathering . This pebble has a polished surface but some folks would not even classify this as a sedimentary pebble. It comes from a diatreme where deep seated gasses explosively erupted through the sedimentary pile ripping loose a chunk of Devonian shale and abrasively polishing it in a matter of a few seconds while it traveled upwards in the explosive pipe.
Litterbugs do serve a purpose.
Minn. This is the same stone used in the Viet Nam Memorial. Some less than scrupulous people do the same thing to pebbles to produce dinosaur gastroliths that they then sell to unsuspecting tourist for exorbitant prices. This was collected when I was at geology field camp as an undergraduate. It comes from the apex of a tight fold that was cropping out along the highway in one of the area, which we had to make a geologic map of. Remember the above underlined terms are descriptive terms, they have multiple possible interpretations as to their mode of formation .