Consumed by the mystery of it all

So, over the past week or so, I have noticed a mysterious material in bike lanes and streets throughout the southern parts of Denver.
The foreign material is often found either in bike lanes or in the street, just left of parked cars.
The material seems to be a type of ceramic - perhaps a tile - and for awhile I thought it was construction-related. The curious material, however, has been spotted in several locations not adjacent to construction sites.
So far here are some of the locations of the sightings:
Evans Street between Franklin and Humboldt
E. Iowa Ave. between Emerson and Ogden
E Iliff between Marion and Lafayette
S Washington between Colorado and Jewell
E Yale between High and Race
The above crime scenes are all within a two-mile radius of The University of Denver.

Here is a close up of a specimen collected at the Iliff crime scene. Those interviewed on the subject have identified the mystery material as ceramic tile of some sort. As of yet, however, there have been no promising leads to an explanation for the presence of such a material in the roads.
I have come up with several of my own explanations and hope that this blog will generate further speculation, provide more evidence and perhaps eventually some answers.
1. Angry sculptors who hate bikers are destroying their defective pieces of ceramics to make the lives of bikers equally miserable.
2. There was an explosion of a tile factory (similar to the recent meat factory incident) that we just haven't heard about.
3. Campus Cycles (centrally located for all of these sitings) has a surplus of tubes for sale and thought this might be a good way to get folks in to buy them. (not a good plan as they don't typically cause puncturing - at least in my experience). [authors note: this assertion is in no way meant to damage the fine reputation of this organization - I am merely seeking the truth behind these unanswered questions]
Further research and findings will be shared as they become available. Please share any pertinent information, clues or your own findings.

Labels: Mystery