Relative age dating

• Paleomagnetism allows for establishing the absolute timing of tectonic and climatic changes recorded in rocks.
• The oldest rocks are typically in the bottom layer and youngest rocks are in the top layer
• Geologists are scientists who study earth and rocks
• Relative age is the age of rocks and geologic features compared with other rocks and features
• Superposition is the first principle that in un disturbed rock layers, the oldest rocks are on the bottom
• Principle of original horizontality, most rock-forming materials are deposited in horizontal layers
• Another principle is that sediments are deposited in large,continous sheets in all lateral directions.The layers will continue until they thin put or meet a barrier.
• An inclusion is a piece of am older rock that becomes part of a new rock
• When rocks move along a fracture line the fracture is called a fault
• Unconformity is a surface where rock has eroded away, producing a break, or gap, in the rock record
• Disconformity- Younger sedimentary layers are deposited on top of older, horizontal sedimentary layers that have been eroded
• Angular Unconformity- Sedimentary layers are deposited on top of tilted or folded sedimentary layers that have been eroded
• Nonconformity-Younger sedimentary layers are deposited on older igneous or metamorphic rock layers that have been eroded
• Matching rocks and fossils from separate locations is called correlation(another word is connection)
• Fossils are the preserved remains or evidence of ancient living things
• Rock formations are often correlated based on similarities in the rock type, structure and a fossil evidence
• Index Fossils represent species that existed on Earth for a short length of time, were abundant, and inhabited many locations