As with most academic disciplines, there are a number of archaeological sub-disciplines typically characterised by a focus on a specific method or type of material, geographical or chronological focus, or other thematic concern. By civilization Certain civilizations have attracted so much attention that their study has been specifically named. These sub-disciplines include Assyriology (Mesopotamia), Indology ( India ), Classical archaeology (Greece and Rome),Etruscology (Etruria), Egyptology (Egypt), and Phoenician-Punic archeology (Phoenicia and its colonies), Sinology (China). By historicity Another main division of archaeology distinguishes: historical archaeology, which examines civilizations that left behind written records; and prehistoric archaeology, which concerns itself with societies that did not have writing systems. However, the term is generally valid only in Europe and Asia where literate societies emerged without colonial influence. In areas where literacy arrived relatively late, it is more convenient to use other terms to divide up the archaeological record. In areas of semi-literacy the termprotohistoric archaeology can be adopted to cover the study of societies with very limited written records. One example of a protohistoric site is Fort Ross on the northern California coast, which included settlements of literate Russians and non-literate American Indians and Alaska natives.Ethnoarchaeology is the study of modern societies resembling extinct ones of archaeological interest, for archaeological purposes. It is often difficult to infer solid conclusions about the structure and values of ancient societies from their material remains, not only because objects are mute and say little about those who crafted and used them, but also because not all objects survive to be uncovered by scholars of a later age. Ethnoarchaeology seeks to determine, for instance, what kinds of objects used in a living settlement are deposited in middens or other places where they may be preserved, and how likely an object is to be discarded near to the place where it was used.Taphonomy'' is the study of how objects decay and degrade over time. This information is critical to the interpretation of artefacts and other objects, so that the work of ancient people can be differentiated from the later work of living creatures and elemental forces. By time period A selective list of sub-disciplines distinguished by time-period or region of study might include: African archaeology, Archaeology of the Americas, Australian archaeology, European archaeology: focuses on archaeologic study concerning the location of the findings. Industrial archaeology focuses on the preservation of material relics of the Industrial Revolution or the