As an archaeology doctorate student, you can choose to write your dissertation on pottery. You can focus your research on a specific style of pottery, such as Corinthian pottery; on a potter, such as Lydos or Makron, both ancient Greek potters, or on a specific type of pot, such as amphorae or kraters. You can perform a comparative analysis of different styles of pottery that emerged from the same area during the same amount of time, such as pottery from both Athens and Corinth in the 4th century B.C. Use the analysis to look into what about those cultures would have influenced different styles of pottery.
You can focus an archaeology dissertation on textiles, regardless of what culture or period you're studying. For example, you can focus on intact Bronze Age textiles that were discovered in bogs in Denmark in the 19th century or on Peruvian textiles discovered in South America. You can look at the actual textiles and their uses and wear, as well as the design and construction, to understand the evolution of the society and their relationship with cloth.
Your dissertation could look into tools that have been unearthed at various excavations from various cultures and civilizations. For example, you can look into the materials that the Mayans used to create tools, including obsidian, limestone, flint, granite and quartzlite. You can look at when and why civilizations began using certain materials. You can perform a comparative study of two civilizations that began using bronze or copper around the same time and what contributed to their adoption of the metal or metal compound.
You can tailor your archaeology dissertation on various types of sculpture. You can focus your studies on a specific period, such as the Hellenistic period or the Archaic period; on a type of sculpture, such as portraiture, architectural sculpture or grave monuments, or on a specific sculptor, such as Phidias, who worked on the Parthenon, and discuss how his work imitated or reflected contemporary society. You can also focus on a specific piece of sculpture, such as the pediment of the Megarian treasury in Olympia. You could perform a comparative analysis of works from two Athenian sculptors from the same age, comparing and contrasting their reactions to contemporary social upheavals.