That is certainly a possibility, Gabe, but I would have to take a look at them to make sure in my own mind. For those not familiar with foundry practice, when you ram up a sand mold for a casting, you use a two-part casting flask consisting of a cope and a drag. The two parts of the flask split in the center to make working on the mold, inserting cores, and removing the pattern easy. The last thing you do prior to setting the flask on the casting floor is insert gates for introducing the molten iron into the mold and vents to allow the air and hot gases to escape. As the iron cools and becomes solid in these openings—and particularly the gate—the iron extensions are still attached to the casting and are generally referred to as sprues. Many of you may recall the same word from the days of your youth when you assemble plastic model kits!
However, even if they are sprues, how did they ever end up where you found them? When I worked in a foundry—back in my much younger days—the sprues all went right back into the crucible with the next furnace charge. Why would anyone transport the sprues out of the casting facility?