Presentation on theme: "DIGGING UP THE PAST ARCHAEOLOGY. WHAT IS ARCHAEOLOGY? Archaeology comes from the Greek archaia (ancient things), and logos (science or theory). Archaeology."— Presentation transcript:
DIGGING UP THE PAST ARCHAEOLOGY
WHAT IS ARCHAEOLOGY? Archaeology comes from the Greek archaia (ancient things), and logos (science or theory). Archaeology is the study of the material remains of the past. Without this science and the work of archaeologists, we would know very little about ancient humans. Archaeologists are specialists in the study of early humans and early civilizations because we have few, if any, written records from this era. To understand this early period in our history, we depend on physical remains. Archaeologists are like detectives, they search out physical clues to solve the mysteries of the past.
WHAT DO ARCAEOLOGISTS DO? Archaeologists work at a dig site to gather data, and then spend the majority of their time in a lab analyzing this data. They eventually write reports on their findings for other people to read about and learn from. The type of work an archaeologist does requires a lot of patience and perseverance, and isn't quite as exciting as the "Indiana Jones" movies make it seem! Depending upon where they are located, some dig sites may be extremely hot and not have any running water (or bathrooms) nearby!
Archaeologists excavate for four kinds of information: They look for Evidence about past environments. Things such as seeds, animal bones and soil. These are called Ecofacts. Evidence of things people made or did that can't be moved, such as house floors or hearths. These are called Features. Evidence of the tools or other items that people made and that can be moved or carried. Objects like arrowheads or pottery are called Artifacts. Organic materials, such as animal and human bones or their fossilized remains. The recognizable remains, or the impressions left by them, of a plant or animal preserved in the earths crust are called Fossils. WHY DO ARCHAEOLOGISTS EXCAVATE?
HOW DO ARCHAEOLOGISTS FIND SITES? There are many ways that an archaeologist find sites. First of all, an archaeologist knows what environmental factors humans have always needed in order to stay alive. These include easy access to water, location on a trade route, and a geographic location that allows for natural protection. With this information in mind, an archaeologist can study maps to locate likely places where prehistoric people may have lived. In addition to this, archaeologists often learn of sites when construction companies clear land to build houses, shopping centres, etc., and they uncover artifacts. Most states have laws that require construction crews to report their discoveries of artifacts and features to a local archaeologist. Once in a while a farmer might happen upon an artifact while working in the field. Archaeologists appreciate learning of these discoveries, and having landowners cooperate with them by giving them permission to investigate these potential sites.
THEY FIND ARTIFACTS, THEN WHAT? Archaeologists study the finds at various sites to unravel some of the mysteries surrounding how humans lived. They are assisted in their detective work by other closely associated scientists called anthropologists, paleontologists, and paleoanthropologists. Anthropologists are scientists who study the origin, development, distribution, social habits, and culture of humans. Paleontologists examine the fossil remains of animal and plant life to understand past geological periods. Paleoanthropologists combine the work of both these scientists.
HOW ARE ARCHAEOLOGICAL FINDS DATED? Radiocarbon or carbon-14 dating is used as a way to determine the age of a find. Physicist Willard F. Libby of the University of Chicago discovered this method in 1948. Carbon 14 or C-14 is an unstable or radioactive form of carbon that has eight neutrons, rather than the six associated with ordinary carbon or carbon 12. All forms of life have organic molecules containing carbon atoms, and have about the same ratio of C-14 atoms to other carbon atoms in their tissues. When an organism dies, the C-14 begins to decay. In radiocarbon dating, the fewer the C-14 atoms, the older the organism. The rate of decay is steady. The half-life of C-14 is about 5730 years. In other words, in 5730 years, half of the C-14 will have decayed. The next quarter decays after another 5730 years. After 50,000 years, there is little measurable C-14 left. Therefore, radiocarbon dating works well for relatively recent objects from the distant past.
MORE ON DATING… To date older materials other techniques are needed. Thorium decay and transformations can be used to date items between 100,000 and 500,000 years old. In rocks, the decay of potassium 40 to argon 40 can be used to date specimens from 500,000 to millions of years old. The decay of rubidium to strontium can be used to date archaeological finds into the billions of years. Archaeologists have other methods as well. Sometimes they measure the amount of surface decomposition on certain stone tolls or the amount of thermo luminescence visible when ancient pottery is heated. During the 1980s, Derek York of the University of Toronto developed a new dating technology using lasers. This method made it possible to get an accurate date from a single microscopic crystal of volcanic material.
ARCHAEOLOGY IS NOT PERFECT Some problems with archaeology.. Limited sources available due to climate, environment, or human encroachment. The Archaeologists cultural, religious, or political bias may blur scientific research. Government in power may limit archaeological finds or taint interpretations. Personal ambitions may taint the interpretations of artifacts/finds. Over excitement may impair judgment and interpretation. Existing interpretations or theories may colour the interpretation of new finds.