What is it, exactly, that went through the ice on Flat Pond?

Yesterday, March 2, I went for my weekend woodland walk. On crossing Flat Pond I noted that there was a peculiarity in the ice on the pond. I wondered if it were a meteor crashed to earth not unlike the one that recently hit Russia. I guess I will have to wait for Spring to come to snorkel down to extract the very, valuable meteorite shards...