I have 3 block test excavations across a site. Bedrock was reached in all three. Immediately above the bedrock in all 3 blocks was a thick accumulation of "gray" loess. Above the gray loess in all 3 blocks was an "orange" loess. OK. In ONLY one of the blocks, wholly within the "gray" loess, was a distinct, thin organic stringer not seen in the other 2 blocks. The stringer did NOT proceed all the way across the block excavation.

How do I portray this?