Block diagram problems concerning relative dating
As a member, you'll also get unlimited access to over 55,000 lessons in math, English, science, history, and more.Plus, get practice tests, quizzes, and personalized coaching to help you succeed.According to the plate tectonic theory, the Earth's rigid outer layer, or "lithosphere," consists of about a dozen slabs or plates, each averaging 50 to 100 miles thick.These plates move relative to one another at average speeds of a few inches per year-about as fast as human fingernails grow.Scientists recognize three common types of boundaries between these moving plates (see diagrams): Adjacent plates pull apart, such as at the Mid-Atlantic Ridge, which separates the North and South America Pates from the Eurasia and Africa Plates.This pulling apart causes "seafloor spreading" as new material from the underlying less rigid layer, or "asthenosphere," fills the cracks and adds to these oceanic plates.
Learn how inclusions and unconformities can tell us stories about the geologic past.Geologists establish the age of rocks in two ways: numerical dating and relative dating.Numerical dating determines the actual ages of rocks through the study of radioactive decay.Sample dating is done by counting beads that represent 235U and 207Pb atoms in a zircon.
Students should be able to read x-y plots and divide two numbers.
The goal of this lecture is come to come to a scientific understanding of geologic time and the age of the Earth.