Final answer:
White or black markings at an excavation represent various elements such as labels in grid systems, historical use of pigments, or cultural practices. They may also show how artifacts have aged or been preserved.
Step-by-step explanation:
White or black markings at an excavation site can serve various purposes, including labelling, decoration, and symbolic representation. In an archeological context, these markings can be part of the grid system used by archaeologists to map the site meticulously. White markings may also represent the intervention of white pigment used historically to highlight patterns or signify particular cultural practices, such as the use of white rocks at family altars dedicated to Pachamama in Andean culture. Black markings could indicate the use of charcoal or other materials by past peoples to create images or text, or they could result from the way certain artifacts have aged or been preserved in the ground.