Summary
Highlights
The lecture introduces the concept of chronology, which is about assigning dates to archaeological assemblages. It builds upon previous discussions on site formation processes, focusing on how to construct chronological sequences for sites and regions. The importance of dating in archaeology is highlighted as a long-standing preoccupation of the field.
The lecture discusses how different cultures perceive time. Western cultures typically view time as linear (past, present, future), a concept that gained popularity during the 18th-century Enlightenment with the widespread use of mechanical clocks. In contrast, many ancient and modern societies, especially those closely connected to nature, perceive time as cyclical, based on seasonal changes, celestial movements, and life cycles. However, some societies, like the ancient Maya and Egyptians, utilized both cyclical calendars for religious and practical purposes and linear chronologies for administrative records.
Archaeological dating techniques are categorized into two main types: relative dating and absolute dating. Relative dating establishes chronological relationships (e.g., older or younger than) between sites and cultures. Absolute dating, on the other hand, provides specific dates in terms of years. Relative dating is considered the foundational basis for all archaeological research.
Relative dating largely relies on stratigraphic observations, which involve studying the layering of geological strata at a site. The Law of Superposition is key here, stating that in undisturbed contexts, earlier layers lie beneath later ones, meaning the oldest artifacts are at the bottom and the youngest are at the top. This principle allows archaeologists to establish a relative sequence of events.
A relatable, non-archaeological example of a cat lying on a pile of papers is used to illustrate stratigraphy and the Law of Superposition. By observing the sequence of events (papers placed, cat lies on them, papers removed, cat returns), a relative order can be established, even without knowing the exact time intervals between each event or the specific age of the objects involved.
Applying stratigraphy to archaeology reveals long cultural sequences. Archaeological stratigraphy operates on a smaller scale than geological studies, requiring careful observation of occupation levels and correlation with cultural sequences across sites. The Law of Association dictates that artifacts found within a particular stratum are associated with that layer's chronological period. Archaeologists reconstruct both natural and cultural transformations affecting a site.
Diagnostic artifacts are crucial for relative dating. These are objects whose styles or features change predictably over time, allowing archaeologists to place them within a specific chronological range. Seriation is a technique for ordering artifacts based on their stylistic and design changes, which can reveal cultural sequences. An example of colonial gravestones in Massachusetts demonstrates how changes in decorative motifs (death's head, cherub, urn and willow) followed a predictable 'battleship curve' pattern over time, indicating periods of popularity.
The concept of seriation is applied to pottery styles in the Tehuacán Valley, Mexico, where changing pottery types were used to establish a relative chronology before absolute dating methods were refined. The lecture concludes with an exercise that applies seriation to modern trash dumps, using musical technology (8-track tapes, Walkmans, iPods, cassette adapters, MiniDiscs) to demonstrate how knowing the introduction dates of these items can help establish a relative chronological order of dumping events.