Presentation on theme: "Archaeology Can you Dig it?. Archaeology The study of past human cultures and the way people lived based on the things they left behind. Archaeologists."— Presentation transcript:
Archaeology The study of past human cultures and the way people lived based on the things they left behind. Archaeologists study the past by examining objects people have left behind. Being a archaeologist is very much like being a detective!
What is the difference between a fossil and an artifact? Fossils Remains of once living things (plants, animals, people), not of things that were made Artifacts Products made by human skill – items made by people
How do archaeologists find sites to explore? What is a site? A site is a place archaeologists wish to explore. At the site, archeologists literally dig, looking for remains of past ancient civilizations. How do archaeologists find sites to explore? They think about… What people need to stay alive: access to clean drinking water, protected place to live, access to trade routes They check out reports of artifacts that have been discovered. Some places are discovered using scientific instruments like radar and sonar to find ruins
At the dig site Before they dig… An archaeologist must receive permission to explore a site Once permission is granted, the archaeologists work in teams exploring they area and they look for evidence – fossils and artifacts How do they dig? Before they begin digging, archaeologists design a grid on the ground using rope and string. Each square in the grid must be carefully searched. A record must be kept of anything found, including what it is found next to it.
What tools do they use? The tools of the trade include: 1.Trowels 2.Brushes 3.Spoons 4.Dental picks 5.Sieves 6.Saws 7.Dust pans 8.Wheel barrows They search each grid carefully. Digging at a site is slow and careful work. Once objects are labeled and removed from the site, they are taken to a lab where the detectives (the archaeologists) examine it to decide what it is, what materials were used to create the object and how it was used.
Dating Remains: Tree Ring Dating Carbon-14 Dating
Tree Ring Dating: Dendrochronology The annual rings of a tree can give scientists a snapshot the environment. Scientists have identified: times of too much water (floods), times of too little water (drought), lightening strikes, earthquakes, insect infestations, climate change. Here's a very basic look at how it works. The thickness of the yearly ring, depends on the environment of the tree. You can begin to make guesses about the environment by looking at the thickness of the rings. Some years, rings will be thick. From this, we might hypothesize that the conditions for growing were excellent. Other years, the rings will be thin. This would signal that, for some reason, the growing conditions were not as good. Perhaps there was a drought or a disease. Tree ring dating can go back as far as 3,000 years
Carbon-14 Dating How does radiocarbon dating work? All plants and animals on Earth are made principally of carbon. During the period of a plant's life, the plant is taking in carbon dioxide through photosynthesis, which is how the plant makes energy and grows. Animals eat plants, and some eat other animals in the food chain. Carbon follows this pathway through the food chain on Earth so that all living things are using carbon, building their bodies until they die. A tiny part of the carbon on the Earth is called Carbon-14 (C14), or radiocarbon. It is called 'radio'-carbon, because it is 'radioactive'. In the 1940s, scientists succeeded in finding out how long it takes for radiocarbon to disappear, or decay, from a sample of carbon from a dead plant or animal. Willard Libby, was an expert in nuclear and atomic chemistry. After the war he became very interested in peaceful applications of atomic science. He discovered that after all living things die, the Carbon-14 within them decrease at a measurable rate. By measuring the remaining Carbon-14 once living things can be dated to all the way to approximately 30,000 years ago.
Carbon is very common on Earth, there are a lot of different types of material which can be dated by scientists. Below is a list of the different kinds of materials which can be dated: Charcoal, wood, twigs and seeds Bone Marine, estuarine and riverine shells Leather Peat Coprolites (samples of preserved feces) Lake muds and sediments Soil Ice cores Pollen Hair Pottery Metal casting ores Wall paintings and rock art works Iron and meteorites Bird eggshell Corals Blood residues Textiles and fabrics Paper and parchment Fish remains Insect remains Resins and glues Antler and horn Water