An important question to resolve is whether the 'chocolate' layer is natural or anthropic. Such a thick homogeneous deposit with no interruptions by evidence of occupation suggest artificial fill. But lack of materials raise suspicion that it may be natural soil from the flooding of the Orcia river to the N. While MZ does have a system of later drains suggesting that diverting water was a concern, the site sits on a plateau overlooking the river below. More, the 'chocolate' is only found in the W half of the site. Paleobotany may help us answer this question.