GEOL423 - ADV COSMOGENIC NUCLIDES: ADVANCED METHODS in COSMOGENIC NUCLIDES

Earth is constantly bombarded with primary cosmic rays, high energy charged particles that interact with atoms in the atmosphere, producing a cascade of secondary particles. These particles, in turn, interact and reduce their energies in many reactions as they pass through the atmosphere. By the time the cosmic ray cascade reaches the surface of the Earth, it is primarily composed of neutrons which produce nuclides in materials such as rocks and sediment at the Earth's surface. Most of these cosmogenic nuclides are produced by neutron spallation within the upper meter of mass. Using certain cosmogenic radionuclides, scientists can date how long a particular surface has been exposed, how long a certain piece of material has been buried, or how quickly a location or drainage basin is eroding. The basic principle is that these radionuclides are produced at a known rate, and also decay at a known rate. In this course, students will learn the details and history of cosmic ray production rate estimates over the globe and through geologic time. A primer to the various accepted scaling methods will be discussed as well as age and erosion rate calculations and advanced and new applications.