been to study instead the stratigraphy of the piece within the deposits of its surroundings. In many cases, however, even stratigraphical dating is impossible, due to the disregard early archaeologists gave when excavating the caves or other sites portable art were discovered in. The destruction of a datable stratigraphy also commonly occurred as a result from ransacking and illegal digs focused not on the study of the material they discovered, but on its re-sale value. All disruptions of the stratigraphy destroy the provenance from which a date could be established. Also posing a difficulty to stratigraphical analysis is the possibility that the time of an object's creation and final deposit can vary greatly. Many portable objects are believed to have served as ritual objects, being passed down from generation to generation, keeping them in use for hundreds or thousands of years. Through the migration of prehistoric man, it is possible that the final resting place of an object is hundreds or even thousands of miles from the point of its original creation. Though difficult, dating portable objects provides an important link in building a chronology of the art, and thus evolution of prehistoric man. While the specific trends associated with a given period are not always agreed on among all scientists due to the subjective nature of art, broad similarities and patterns can be formed which work to augment the archaeological study or prehistoric man by forming observations and theories on which other archaeologists can develop. References Prehistoric art