You may of hit the nail on the head Richard,about 3/4 of a mile,, 2 steamers hit head-on years ago,this piece (Brick)was located at a old telegraph pole along side a swamp(flood,n bog) ..Railroad, past practices,then were to dozes, clam and bury evident of derailment,and wrecks,,(out of site out on mind,)I,d say there may be more debris buried beneath the surface, but it may stand to reason, fire bricks from the boiler on the steamers,transhipped to a location for easy disposal.
.Thanks Andy